Chapter Text

Author's Note:

Hi, just one quick thing before we get started: you can read this, even if you haven't read "Realisations". Anything relevant from that story will be mentioned here, but of course you are welcome to read my previous story as well.

To everyone else, welcome back; this story picks up just a few days after Realisations' final chapter, so you could see this as a continuation, but with new protagonists now.

There will be a few images/drawings from time to time, given that one of the protagonists is an OC, to help you picture her, though I don't know how many yet. Might slow the publishing of new chapters a bit.

Enjoy.

Prologue

It was a pretty normal day within the body. No major incidents, just a few germs at the common entry points of the body as usual, which were quickly disposed of by the immune system. It had been like this for some time now and U-4989 was frankly feeling a little bored. There wasn't much for a neutrophil like him to do, except to patrol the body again and again, so he'd opted to distract himself whenever he could, whether this meant playing with the platelets or testing out a new weapon.

His makeshift spears were getting better, as were his skills with the polearm. As it turned out, throwing them seemed to work much better than slashing. If only he had a decent place to practice; he would keep an eye open on his next patrol.

Today however he'd gone to the nasal cavities, a part of him hoping to encounter at least a stray Streptococcus. On the other hand this place had really good buns. After walking around for a bit 4989 sat down with some tea and his still steaming lunch, comfortably leaning against a tree by the side of the road. He watched the other cells doing their work as he enjoyed his meal, a far cry from the germs he mostly consumed. As a phagocyte he was used to the taste, but nothing could hope to beat fresh food made by local cells. Plus it was usually much sweeter.

He was eating his last bun, when he spotted a familiar face in the crowd. It wasn't AE 3803, but another erythrocyte, who he recognized thanks to her dark auburn hair, neatly braided with the exception of short, wild strands framing her face. During the Plasmodium invasion some weeks ago, she had been the first infected one U-1146, NK cell and he had encountered alive and the first, who had been saved.

Plasmodium falciparum

Unicellular parasites, causing Malaria, introduced to a host body by the bite of an insect, most commonly the Anopheles. At this stage they are called sporozoites and first infect liver-cells (hepatocytes), maturing into schizonts, and multiply, becoming merozoites, before getting released into the bloodstream, where they invade erythrocytes. There the parasites continue to multiply asexually and devour the haemoglobin (having reached the throphpziote-stage), destroying the host cell in the process and move on to new red blood cells. This circle continues in the bloodstream, while some turn into male and female gametocytes, which can be absorbed by a mosquito again, where they reproduce sexually, creating new sporozoites.

It could have gone very differently. At that point they had already found a dead erythrocyte and after seeing that she was victim to a parasite, NK had initially suggested simply killing her, the host. Both U-1146 and he had stepped in, however, given that it hadn't been a virus , something that couldn't even infect an erythrocyte , and prevented an execution . As a result the bracelet-like parasite had been successfully removed , allowing her and many other erythrocytes , among them 3803, to recover . 4989 had only seen the auburn haired red blood cell once since then, when she'd approached him to timidly thank him for keeping her safe from NK. An unexpected gesture, but one he'd greatly appreciated.

It had caused 4989 to wonder if it was possible for him and his fellow white blood cells to befriend more erythrocytes. AE 3803 was currently the only one he knew of, her senpai AA 5100 maybe as well, something he found to be a shame and a bit ridiculous, given that there were millions of them. There had to be a few more exceptions.

He often saw other cells talking and laughing with each other, playing games and frankly it was something he would like to be a part of, especially on slow days like this. As it was, most none-immune cells, with the exception of platelets and a few others, kept away from leucocytes; he couldn't even approach most of the erythrocytes he was constantly surrounded by without making them uneasy. Some were even fearful, which frankly kinda stung. After all, they were here to protect.

Sure, white blood cells sometimes got a bit intense during battle, but none of them would ever harm the cells of this body. That was of course unless they were for example infected, but at that point they really weren't themselves anymore; frankly virus-infected cells were pretty much dead already, mere husks under the pathogen's control. Were those cells in pain? Probably, given that the viruses latched on with sharp appendages before taking over from the inside. Killing them could be seen as an act of mercy, an end to their suffering.

In any case, 4989 really wanted none-immune cells to be more comfortable around them, at least comfortable enough to have a normal conversation with. And this erythrocyte seemed like his best bet to get started. She'd met him, he'd helped save her life; that was better than nothing.

Only question was, how should he approach her? Just walking up to her didn't seem like a good idea, might only make her nervous same as with all the others; she certainly had been when she'd sought him out. Could she perhaps even feel threatened, especially considering her experience with NK? That was the last thing he wanted.

4989 watched her pass by a while longer, seeing the CO2 box in her arms, and as he wondered which route she might take, he suddenly had an idea. It was worth a shot.

...

On this calm day AC found herself very much enjoying her trip though the nasal cavities. It had been a great idea to stop for a nice break with buns and a relaxing, warm footbath, which frankly after hours of nonstop walking she'd ached for even more than the glucose. She really needed to come here more often; it frankly was one of her favourite spots in the body, despite occasional germ invasions, though once you had made it past the first immune cell those things took care of themselves. Now feeling refreshed and back to a hundred percent, the young erythrocyte was on her way back to the lungs, humming contently to herself.

Fleet of foot she walked down the road, before deciding to take a shortcut through one of the smaller vessels, not a capillary, though it would be tight if two cells were to walk side by side. But it also meant that there was very little traffic; most erythrocytes preferred the main road along the shops, where they could comfortably catch up with friends. Besides, AC had a feeling that she would only be tempted to take another break at one of those shops. While she wasn't in a hurry yet, she knew she would be if she were to make another stop there.

This whole place just tempted you with so many ways of procrastination. Not that she necessarily minded; just doing delivers could be a bit dull after all.

She hadn't made it too far down the slim road, when unexpectedly a voice addressed her from the side. "Uhm miss, could you help me out?"

Confused AC turned around and in the little gap between two buildings saw one of the neutrophils. She needed a moment, but then realized that she knew him, or at least she had met and talked to him before. "U-4989?" He was the one who had helped save her life, something she'd thank him for only a short time ago. It had taken her days to convince herself to seek him out and just as many to find him. Not to mention that she'd hesitated and ducked out twice, before finally mustering the courage to do actually approach him and just the other day his partner as well.

With a surprisingly friendly smile for a leucocyte, he greeted her. "Yep. Sorry to bother you, but I well...," he chuckled embarrassed. "I kinda got stuck."

Stuck? For a moment she simply stared at him, admittedly dumbfounded, but yeah, there he was with basically only his head and arms sticking out. "Oh, I..." was all AC was able to mumble nervously; he was still a white blood cell after all. Every instinct told her to keep a distance.

"If you could just pull at my arm a little," the neutrophil requested a pleading look in his grey eyes. "Please?"

Back in the day she'd never paid much attention to the leucocytes. They were, of course a constant presence in the blood stream, but always somewhere at the side, almost invisible. Only when things went wrong, you could not help but notice them, yelling for blood, eyes wide with murderous intent. But things had changed a little since the parasite, besides she owed him; big time. "Alright."

The erythrocyte put her box aside and slowly, carefully, took hold of his wrist and lower arm. Placing one foot against a wall next to him, she began to pull. Her first attempt was a little hesitant and didn't accomplish anything. She took a deep breath and this time pulled with far more strength, tightening her grip.

"Almost," he encouraged her.

"Ugh."

And suddenly he was free. The erythrocyte stumbled backwards, until her back hit the wall of the building behind her, staring at the neutrophil, who was still being propelled towards her. Suddenly panicking her eyes widened; was he going to crash into her!

Tripping from one foot to the other, same as she had, he fought to regain his balance and she quickly closed her eyes, raised her arms, bracing herself for the impact. But it never came. When she looked again, the erythrocyte saw that he'd managed to stop himself just in front of her, a hand on the wall she had stumbled against and his smile from earlier had made a return.

"Ah, thank you miss," he said, and his eyes darted to her beret. "AC 4293."

"You're welcome, Kōchūkyū-san," she told him, yet pressed herself against the wall away from him. This was damn close.

Thankfully he seemed to notice her uncomfortableness and finally stepped back. "Sorry for the inconvenience. I swear this doesn't happen often," he hastily added, sounding a little flustered.

"I take your word for it," the erythrocyte mumbled as a reply, relaxing a little.

There was an awkward pause and to her surprise, she saw him rub his lower arm, almost as if he too was nervous. "I wanted to ask the other day; how have you been recovering? I mean after the parasite...?" So, he'd recognized her as well.

AC looked up, finally meeting his grey eyes, oddly enough being greeted by a soft gaze with what seemed to be honest concern. "Oh, well I've been doing fine," she answered somewhat perplexed, feeling a little disarmed by his friendly attitude. "I guess I was lucky it got removed so early on. Actually I was allowed to go back to work again within a week. Still have that scar though." She lifted her right arm, showing the red dots that made up the small bite-mark just beneath her glove. "I tried to cover it up, but couldn't find anything suitable; seeing it is a bit unnerving." Wait, why was she telling him all this? Sure he had been nothing but friendly, but still.

"I suppose longer gloves aren't an option?" he suggested.

That was actually something she had considered. "If there are any, I haven't found them." She shrugged, her shoulders scraping the wall she was still leaning against. "Who knows; maybe I get used to it."

"Maybe it will disappear yet," the neutrophil reckoned optimistically.

"Maybe." Frankly AC didn't believe that, but it was probably possible. She looked past him and spotted her box, still sitting innocently on the ground. "I...I should really get going. The carbon dioxide...," she began to explain, hoping to be able to excuse herself without being too rude. This all was too weird for her.

His eyes widened. "Oh, right." He pulled at his cap and made a quick bow. "Sorry, I didn't mean to keep you. Thanks again, for me helping out."

Somehow AC 4293 managed to muster a shy smile. "Sure." She picked up her box, and gave him a last nod before departing. "Bye."

Displaying a much wider smile than her, he waved. "Bye! Take care!"

With a few steps a much relieved AC exited the alley and stepped onto a main road again. She took a deep breath. Okay, what had just happened? Or better yet, what in general was happening?

Usually, back in the day, when she took notice of neutrophils, or white blood cells in general, they never failed to manage to make her cytoplasm freeze. Sure, they protected the body, but it was difficult to feel safe around them, when they only seemed to be interested in killing things. The only exception to this rule seemed to be the macrophages, but their constant cheeriness, even in the midst of battle could sometimes be unsettling in its own right.

Now however things seemed a little more...complex? When she'd been infected with the Plasmodium, she'd turned to the white blood cells in pure desperation after seeing her friend killed by the very same bracelet-like parasite, her haemoglobin devoured by that monster. But, with the exception of the NK cell, every leucocyte had been nothing but obliging towards her, doing their best to help her.

AC vividly remembered the neutrophil U-4989, how he'd tried to remove the parasite with his knife, careful not to cut her. Did she really have a wrong picture of them all this time? Or at least a distorted one?

But her line of thoughts was interrupted when she spotted a familiar group not far off, three of her closest friends she'd grown up with. Putting on a smile and pushing those thoughts aside, AC 4293 joined them.

"Hi everyone."

"Hey AC, are you alright?" another young woman with short black hair asked, looking strangely enough somewhat concerned.

"I'm fine CT 2980," she assured her, assuming that they had seen her engrossed in her thoughts moments earlier. AC had been told that she could sometimes look troubled whenever she was, even if nothing was wrong. Or walked into things; rarely, but it had happened.

Another of her friends, AD 5022, didn't seem quite convinced however, narrowing his eyes, which were of the same dark brown as his hair. "You're sure? We thought that neutrophil might have bothered you."

"What?" AC turned around and saw U-4989, who had probably left the alley right after her, walk down the road away from them. Oh. Quickly she placated her friends. "No, he just wanted to know how I've recovered." Even to herself it sounded peculiar, but it was true. So weird. "He's actually one of the white blood cells that helped me with the parasite."

"I thought they wanted to kill you," 5022 replied with a deep frown.

AC 4293 shook her head, but what else did she expect from his occasionally selective hearing. "Only the NK cell. He and his colleague were the ones, who convinced her to try cutting the parasite off first, remember?"

"Hm." She wasn't exactly surprised. Generally speaking all red blood cells were at least somewhat afraid of the immune-cells, but 5022 was among those, who took it a step further. After seeing them wipe out hundreds, if not thousands of virus-infected cells on his very first day of work, he'd come to deeply mistrust them. Therefore, AC couldn't exactly argue with him, there was no point really, as it was like running against a brick wall, even if she disagreed.

"You have to admit, they're still creepy," CT 2980 added, before shivering a little at her next thought. "Just the way their eyes change when they spot a germ, freaks me out every time." Now with that AC could agree with, despite feeling reluctant to voice that opinion. Right now she couldn't help but picture the neutrophil's kind smile from mere minutes ago.

Meanwhile AD 5022 nodded. "Don't want to know what would happen if you were ever caught in the crossfire or happened to be in the way during an incident. Probably would just cut you up as well; those guys get crazy."

FP 1564, who had stayed out of the conversation until now, started rolling his eyes behind the few strands of light brown hair crossing his face. "I've never heard of a white blood cell killing a healthy erythrocyte, even by accident," he pointed out calmly.

AD folded his arms. "Well, we are millions. Who knows if we would ever hear about it should it happen." That idea was horrifying, but AC just couldn't believe it.

"Now you're being a bit ridiculous," FP 1564 scolded him in her stead. "A white blood cell killing a healthy and functioning cell is a serious crime; the rest of the immune system would be after them."

AC nodded, glad there was at least one voice of reason around. "He's right. They might be crazy and a bit intense, but only because they take their duties so damn seriously. Yeah, it's scary, but I'm sure they wouldn't hurt us." Without reason anyway. Subconsciously her fingers brushed over the wrist-scar.

"Still, the less contact I have with them the better," CT 2980 declared decisively, putting a hand on FP's and AD's shoulders as a calming gesture, before this could turn into an argument. "No reason to risk it."

The two nodded, while AC 4293 only sighed. She really liked her friends, however this remained a topic better not discussed with them; well, with the exception of FP 1564 that was. It wasn't like she didn't have any reservations towards white blood cells, but CT, and AD especially, just always expected the worst from them.

She looked over her shoulder, to where the neutrophil had disappeared in the crowd. She suddenly recalled what his colleague U-1146 had said to the NK cell. We're supposed to keep the body safe, which includes the cells living in and providing for it. If we can save her, we will.

A faint smile tugged at the corners of her lips. They were wrong in some respect, she herself had been, at least about some leucocytes.

But perhaps on the other hand they were right about better not risking anything regardless. Who knew how many thought just like that NK cell? Simply kill the host. The image of that female lymphocyte standing before her, sword drawn, looking down at her with a cold, pitiless expression, still send shivers down AC's spine. What if you came across someone like her again?

Yeah, perhaps better not risk it.

...

U-4989 continued his patrol, replaying his interactions with AC 4293 in his mind. It hadn't gone quite as he'd hoped, though at least he finally knew her designation. Still, she really had been afraid, or at least that had been his impression. He couldn't have been that scary, right?

Nonetheless 4989 smiled a little; after all, she had helped him, despite her reservations and she hadn't run off, so on the other hand it also could have gone way worse. But it was obvious that he had to do something if this was to go anywhere.

Question was: what could he do?

There was really only one example he could take cues from. U-1146 had helped AE 3803 whenever he could; assisted her navigate the body, protected her from germs. But AC 4293 probably didn't get lost often enough for that to be a viable approach, 3803 was pretty unique in that regard after all, and the latter required him to just happen to be around whenever she was endanger, which wouldn't exactly be easy. How ever had 1146 managed that? Maybe he was luckier than the fluffy haired neutrophil gave him credit for.

No, he needed to do something else to alleviate her fear. It was bad enough that her scar still haunted her every day; she didn't need a neutrophil scaring her as well. It really was a shame he couldn't do anything about that bite-mark, especially given how he'd been unable to remove the damn parasite in the first place.

Suddenly 4989 stopped dead in his tracks. He had an idea.

Chapter Text

Gifts

For the next few days things remained calm, but 4989 found himself not minding so much anymore. He did have a new little project, after all. At first he searched for the right material, something that would also be comfortable to wear, until he found it during his last visit to the spleen when he'd needed a new uniform. It was smooth twine, actually the same type they made white shoe laces from, though he now had another purpose for it.

So today he'd found himself a nice little spot in the shadow of a tree from where he had a good view across a busy crossroads, where blood from the liver entered the inferior vena cava, since he still had his duties to fulfil and got to crafting. The noise all the other circulating cells made didn't bother him in the least, given that he was used to it, letting the chatting and sounds of countless footsteps fade into the background.

For some time 4989 was able to continue his wok undisturbed, making good progress, until he spotted his fellow neutrophil U-2626 walk up to him, just as he was about to exit the liver. "Hey, 4989," his friend greeted him, joining him beneath the tree, a fresh tea in one of his hands.

"Hey, how was patrol?" the fluffy haired neutrophil asked, without stopping his work.

"Uneventful." He leaned closer to get a better look. "What are you making?"

"Oh, nothing special," 4989 replied somewhat evasively. "Just a little something to pass the time."

"So you picked up braiding?" his friend clarified, prying, or at least that was what 4989 assumed, given that it was difficult to tell with those long bangs covering 2626's eyes completely.

"It's a gift if you must know."

"For whom?" 2626 asked curiously.

4989 hesitated for a moment, stopping his work, but then again why not tell him. He didn't mind a bit of friendly teasing, which he was certain would follow. "Remember that erythrocyte, who came to thank me that one time?"

"Yeah, sure."

"Well, I met her again the other day and turns out she still has a scar," he explained, tapping his own wrist where she carried the bite-mark. "Understandably having a constant reminder or her near-death experience isn't too pleasant, especially after having seen someone she knew die from that parasite, but so far she hasn't found a way to cover it up properly."

2626 inclined his head, in sense his way of raising a questioning brow. "Don't you think a bracelet is a bit insensitive then?"

That was indeed what 4989 was making; he was braiding the strings to make them into bracelets, two to be exact. He'd been uncertain about the size at first, but had taken a few measurements with a confused AE 3803's help. AC 4293 was only a little taller, so he doubted that there were any significant differences between their wrists. Additionally, with AE having the same scar, it had been easy to determine how broad the bracelets needed to be.

"Well, what else is she going to wear? Vambraces? A jumper?" He had naturally thought about whether it was insensitive, but a bracelet remained the best solution, and so he'd opted to at least make them different enough to not be reminiscent of the parasite. Plus it matched her hairstyle. Of course there was still the chance that she didn't like them, but it was worth a shot.

"You could pick up knitting while you're at it; it does get nippy in the extremities sometimes," his friend teased, referring to the jumper-idea. "But point taken. So, you're trying to make friends?" 2626 clearly remembered him saying how he wished to actively raise the number of unafraid erythrocytes some time ago.

"Of course; I don't want to make erythrocytes jump every time I address them." The fluffy haired neutrophil confirmed, with a confident smile. "But you have to start somewhere and she seemed like the right person." Honestly the list of viable candidates had been a very short one.

"What about 3803's friends?" Admittedly, the only other on said list.

4989's smile faltered. "Honestly, she doesn't have too many, aside from maybe her senpai AA 5100." At least she seemed to be the erythrocyte that could be seen most often around 1146's girlfriend.

"But you're trying...what's her name?"

"AC 4293."

"You try with her first?" Confusingly there was now a grin on 2626's lips.

"Having helped save her life just puts me in a good position," 4989 noted; otherwise, she probably wouldn't even be willing to talk with him. "But hey, if you want to try with AA 5100, go head."

His friend merely shrugged, but his grin remained. "And this has nothing to do with the development between 1146 and 3803?"

Even more confused 4989 frowned. "Why would it have anything to do with them?"

"Nevermind, just curious. Well, got to continue my round. See ya." 2626 waved goodbye and re-entered the blood vessel.

"Yeah, see ya." It was only then that the fluffy haired neutrophil finally realized what his friend had implied. "Wait!" he quickly shouted after him, jumping to his feet, but 2626 was already out of earshot. "No, it's not like that!" But his friend was gone.

The neutrophil huffed annoyed and sat back down. It really wasn't anything like between those two lovebirds. Frankly 4989 didn't even know AC 4293; for all he knew she could still turn out to be an arrogant, mean-spirited or spiteful person, but that was the thing. He didn't know. Whether he liked her or not would depend on how their future interactions would play out, on what he would learn about her, if she gave him the chance. He didn't her know and that needed to change, simple as that.

Regardless, right now she was an erythrocyte, who had gone through something horrible and was still coping with it. He just wanted to do something for her and hopefully this little gift would help with that.

AC 4293 was travelling alone down a road along the mouth, somewhere close the root of a tooth, looking for the right address to deliver her basket of nutrients to. It had to still be several blocks ahead, though it wasn't easy to say with all of the buildings looking pretty much identical. But that was the thing about blood vessels; they were pretty much the same everywhere. Not exactly what she would call visually stunning. Maybe on her way back to the lungs she could go past the vocal cords, watch the cells there for a bit. She only had to be careful not to linger for too long.

"AC 4293?" a male voice suddenly addressed her; it was familiar, but she couldn't immediately think of a face.

Curious she stopped and turned around, her eyes widening almost immediately. AC hadn't expected him. "Oh, neutrophil!" she greeted the leucocyte she knew as U-4989 surprised, tensing up a little. "What are you doing here?"

"I was actually looking for you," he admitted with the same friendly smile she'd seen last time.

Oh; was that bad? Was something wrong? Leucocytes generally didn't talk to you unless something was amiss. "Looking for me?" She was forcing herself not to take an instinctive step back, instead grasping her braid that was lying across her shoulder today tightly with one hand.

Apparently he noticed her anxiety, since his smile faltered and he looked somewhat abashed. "Don't worry, it's nothing bad. I'd just like you to have this." He pulled something from one of his pockets and held it out to her. "You said you were looking for something to cover your wrist with."

AC hesitated somewhat confused. She couldn't see what it was, but it had to be small, given that it fitted in his closed fist. Very slowly she offered her own hand and felt him place something light in her palm. The erythrocyte took a moment to examine his gift. "Is that...?" Bracelets.

"I...I made them myself. Hope I got the size right," the fluffy haired neutrophil told her, apparently quite nervous now, rubbing the back of his head. "You can adjust them a little," he added hastily, pointing at the loop each had at one end.

Made them himself? Both astonished and still puzzled she looked at him. "Th-thank you?" Was all she could stutter.

His lips curved up into a sheepish smile. "Just in case I made two; you know if you need a spare or want to wear one on each arm." He tugged a little at the peak of his cap, perhaps waiting for her to say something, but AC currently felt a bit speechless and didn't know what to say. "Anyway, I didn't mean to keep you from anything." He waved. "Bye." And almost fled back into the bloodstream.

For what felt like at least a whole minute AC 4293 simply stared after him, until eventually she looked at the bracelets in her hand again.

He'd apparently made them from white string and very neatly braided them. It honestly was well made; he must have spent some time working on these. AC finally smiled, her fingers touching her lips. That was so sweet. He'd asked about her well-being and actually put in the effort to try and make her feel better. A neutrophil, who until just the other day hadn't even known her number.

AC put on the first bracelet. With a bit of fiddling it fitted perfectly around her wrist and completely covered the little bite-mark. The smooth twine felt nice against her membrane and was so very light she could hardly feel it.

Suddenly she felt a pang of conscience, stabbing her right in the chest. Being the idiot that she was, she hadn't even properly thanked him, just stuttered. Honestly, what was the matter with her, she could do better. He'd been nothing but nice to her; it didn't just deserve, but demanded some acknowledgment.

She had to seek him out and she had to stop acting like a scared little erythroblast around him; her fears couldn't keep getting the better of her, it was ridiculous, regardless of what CT 2980 and AD 5022 believed. This neutrophil certainly wasn't dangerous.

...well, as soon as she wasn't occupied with her duties for a moment, then she could try to find him.

Right now she had to find that blasted building;the beige one with the balconies. She looked down the street where everything fit that very description, until she glanced at the house number 820. The one of her card that had come with the basket read 2970. AC sighed. Better get going.

...

Well, this hadn't gone too badly.

With his every mitochondria still pulsing like crazy, 4989 continued his patrol, a relieved smile on his lips, feeling rather satisfied. Honestly, he hadn't been sure how she would react, but he took taken aback and a bit puzzled over freaked out any day. Hopefully, she would wear the bracelets, though at this point he was simply glad she'd accepted them in the first place.

While he still didn't know really anything about her, he'd come to the decision that she was quite cute, if not the same way AE was. Her eyes were a little sharper, giving her slightly more mature features, and were bronze coloured instead of amber. Though he had never seen them side by side, the neutrophil guessed that she was a little taller as well, about the same height as AA 5100, who he did sometimes see around 1146's girlfriend.

She also seemed to have a habit of pulling at the messy strands framing her face or holding her braid when she was uncomfortable or nervous. He would watch out for that next time they talked, maybe it could help him avoid making her uneasy. That was if he could actually think of something to talk about, instead of rambling like an idiot. Better luck next time, whenever that would be.

A few days passed and another patrol had started out rather relaxed as they so often did. But today things didn't stay quiet. Somewhere along his way, while 4989 stretched his arms, wondering idly if he should get some tea, his receptor suddenly went off. He whirled around excited, scanning the street he'd been walking along, as well as the apartment buildings flanking it, but everything seemed to be in order. Well, a few erythrocytes looked at him concerned, backing off a little, but that was it.

Then noises reached him from further down the road, sounds of blades clashing and solid objects breaking and the neutrophil started running. Finally some action! It didn't take long until he saw the first cells fleeing in his directions, clearly trying to get away from something.

When 4989 reached a little plaza, booths offering glucose-goods around the central lawn, he noticed something. Did the noises come from two different directions? Great, where should he go now?

His dilemma however quickly solved itself within mere seconds. One fellow neutrophil came crashing through an alley to his right, while another came flying from between two booths to his left. Both ended up lying side by side only a little further up ahead, both equally surprised to see each other. And 4989 recognized them too, when he heard their voices.

"U-2626?"

"2048?"

"Hey, guys! What's going on here?" the fluffy haired neutrophil asked, joining them as they sat up. It was in that moment that the germs they had been fighting appeared.

2626 pointed at the alley, from where two bacteria of violet colour and outfitted with black claws emerged, their grins exposing razor-sharp teeth. "Pneumococcus, with capsule."

Meanwhile, 2048 pointed at three female looking germs, which had taken position on top a booth selling spun sugar, as its owner ran away in fear, almost stumbling over his own feet. They were reminiscent of the Staphylococcus aureus, though their bodies were beige coloured, coated with some sort of mucus and seemed frailer in overall appearance. "Staphylococcus epidermidis." The other two stared at him disbelievingly. "They just got a lucky hit when I killed two of their friends, okay," 2048 quickly defended himself.

4989 chuckled, drawing his knife. "Ah, another beautiful day at work."

Staphylococcus epidermidis

A bacterium that is part of the normal human skin and mucosal flora. While usually not pathogenic, there is a risk of infection for patients with compromised immune system and it can cause hospital-acquired infections, even leading to sepsis. It is especially known to cover catheters or other surgical implants (such as prostheses) with a biofilm, a mucosa-like, thin layer of microorganisms sticking together. Following surgery at the heart, it can also cause endocarditis, the inflammation of the inner heart-layer.

The Pneumococci wouldn't run; with their capsules they were unfortunately pretty safe, but the same couldn't be said for the Staphs. If they deemed the situation to dangerous or all three of them were too occupied with the violet germs, they could escape and cause who knows what damage to the body. No, they needed to go first, so they could all focus on the real threat here.

"Now die!" Without another moment wasted 4989 ran towards the booth and pulled himself up. Two of the bacteria managed to leap off, getting some distance between themselves and the neutrophil, but he had grabbed the other by the ankle and dragging her back, making her fall flat on her back.

"Ahhh!" the Staphylococcus screamed in agony as 4989 cut across her torso, though he was already fixating his attention on the reaming two, glaring at them out of the corner of his eye. Cytoplasm splashed across his uniform, colouring the front of it red, but as he rose up again from his crouching position, 4989 noticed that it wasn't the only thing covering him. "Ugh; that's sticky," 4989 said disgustedly, looking at strings of a mucosa-like substance stretching between his weapon, hands and the bacterium's body.

"Yeah, I know," 2048 replied, while he closed in on the other Staphs below, showing the same pale, viscous strings stretching between his owns fingers, as well as his arms and torso.

"Could use a bit of help here too, guys," 2626 reminded them, also back on his feet and in combat stance before the approaching Pneumococci, entering the plaza now.

"Keep them occupied; we'll quickly finish this first."

"I'll try not to get killed," came the dry retort.

2048 chuckled, before he suddenly charged at the Staphylococci, eyes wide, baring his teeth. "Die germs!"

The bacteria, having realised that they no longer outnumbered their initial opponent tried to run as predicted, but 2048 was quicker, cutting down the first effortlessly. 4989 swiftly threw a handful of blades at the second, as he jumped from the booth's roof. "You're not getting away!" They hit their target from lower back to the base of the neck, the germ flinching in pain, slowing to a near stop just as his feet touched the ground. Easy prey. Then he grabbed her arms, probably dislocating it as he spun her around and slashed through her throat with one clean cut. Done.

Satisfied, starting to really feel the rush of battle, 4989 turned to 2048 and both looked to their friend who was fending off the two Pneumococci, blocking their claws and tentacle-like flagella. He was really in trouble, his arms already covered with what were hopefully only shallow cuts, and both neutrophils rushed off to aid 2626. "So, what now? We might not be able to get through the capsule," the fluffy haired neutrophil noted, furious at seeing a friend injured.

"True, but maybe if we attack together at once, they might not be able to cover all angles," 2048 pointed out.

"Worth a shot." In any case, they couldn't allow those germs to run amok.

"Let's go!" 2048 threw some of his own throwing knives, which did little besides embedding themselves in one Pneumococcus' capsule. But it drew its attention away from 2626.

The attacked germ jumped at 2048, lashing out with its tentacles, forcing the neutrophil to stop dead and block the attacks, one claw brushing his cap, slicing through the fabric. 4989 used the opportunity to flank it, trying to get a hit at the neck, only to be stopped by the honeycombed-patterned sheet of the capsule taut between two of its tentacles, which the Pneumococcus used like a literal shield.

That triumphant grin it gave him only served to enrage him more. Snarling 4989 drew a second knife and threw it from below, managing to get it under the shield. With some satisfaction he saw his blade pierce through the pale membrane of the abdomen, between the violet pieces of exoskeleton, embedding itself to the hilt.

The bacteria hissed in pain, just distracted enough for 2048 to advance again. 4989 quickly continued his attack as well, both forcing the germ into the defensive, to hide behind its dual shields and together they pushed the invader against the nearby building, cornering it. The moment its back hit the beige wall of the apartment complex, the germ lashed out furiously, desperate to keep the two neutrophils at a distance.

Much to 4989's displeasure it worked. Sure his blade had merely been able to scratch the capsule, but now every time he took a step closer the tentacles would almost get him, aiming for his head and chest. It was infuriating.

2626 on his own was having even less success, still fighting close by, trying to push his opponent towards his friends. Getting both germs into one spot again would be a start, especially if there was no way out for them other than through the leucocytes.

But that was all they could do. Contain, perhaps tire them out.

Frankly the fluffy haired neutrophil didn't like that idea very much; it would be an arduous task and he would prefer a quicker solution. After all, they could get exhausted as well and he had no intention of getting injured or even killed by such common bacteria, nor would he allow his friends to suffer such a fate.

Suddenly 4989 noticed another white shape to his left, another neutrophil by the looks of it. From the corner of his eye, he saw him dash right into the battle, straight at the Pneumococcus 2626 was fighting. A powerful kick pushed the germ against a wall next to the other. 4989 grinned; now they were both cornered, capsule or no capsule. "Sorry I left you waiting!" the newcomer apologized.

"1146? Didn't know you were around," 2626 noted as the four of them surrounded the now nervous invaders.

"I was, but when I saw what we were up against I got us a bit of help," he told them.

"Hey, everyone!" The other three neutrophil glanced over their shoulders to see a familiar, brown-haired lymphocyte.

"Hi, B-Cell," 4989 greeted him relieved to see their fellow leucocyte.

The blue-clad cell nodded and looked at the confused Pneumococci. "Capsule?"

"Yes; the bastards are blocking all our attacks," 2048 explained.

B-Cell charged his weapon, the lines along the Y-shaped lighting up green. "Not a problem, ready when you are." Like on cue the neutrophils parted, exposing the two germs. 4989's grin broadened; game over.

"What? No, wait!" one Pneumococcus screeched, now panicking, the other trying to run, but too late. B-Cell pulled the trigger. Both bacteria were showered with the antibody-saturated solution, both hissing in pain as the little proteins latched onto them.

"My capsule!" It was gratifying to see holes appearing in the protective structure, as if B-Cell's solution was made of acid.

Antibody opsonisation and complement activation

Antibodies can fulfil several functions, two of which are:

The marking of pathogens, referred to as opsonisation; antibodies latch onto a target's surface, thus attracting phagocytes, such as neutrophils and macrophages, and allowing them to ingest and eliminate their targets.

Complement activation; antibodies can attract and activate specific proteins within the blood plasma. Some of them can also do opsonisation, while others go to a targeted cell, like a bacteria, link together and create a complex that perforates the membrane, leading to it breaking down (lysis), killing the cell.

Seizing the opportunity immediately 1146 leaped forth, blade flashing just as 4989 was about to do the same. "Die!" And slashed through the first throat, grabbing the other germ by its shoulder as it tried to flee, pulled it towards himself, just before ramming his blade into the back of its skull. Both Pneumococci collapsed, dead before they hit the ground.

"Show off," the fluffy haired neutrophil teased him, acting like he was pouting a little, kicking one of the corpses as if to make sure it wouldn't get back up again.

"You can get the next one," 1146 assured him, patting him on the shoulder.

The fluffy haired neutrophil expression brightened. "Promise?" Truthfully he didn't care that much, but where was the fun in that?

And indeed his friend chuckled. "Yeah."

"Hey, you got two as well; like you have anything to complain about," 2626 remarked, putting his knife away. "I had to defend myself the entire time and didn't get a single kill in the end."

"Oh yeah? One word: biofilm." 4989 spread his arms, showing off the disgustingly sticky strings. "Want a hug?"

The other neutrophil quickly took a step back. "I'm fine with just cytoplasm, thanks." He quickly declined with a grin, one of the few expressions easily discernable, despite the bangs.

"You're welcome," B-Cell piped up slightly annoyed in the background.

...

Come on get a hold of yourself. He's bloodied, but he's still the same cell, who took the time to make bracelets for a random red blood cell, just because she was freaking out over some scar. He himself must have dozens! He's still the guy who got stuck between walls and the first trying to help you with the parasite. Calm down. It's just cytoplasm...a lot of cytoplasm.

At first AC 4293 hadn't been sure how to find him, but when she'd heard about a nearby germ attack she just had to check. Her reasoning had been that in all likelihood every neutrophil in the area would probably have responded to the incident, which just had to increase her chances of finding him. And indeed, there he was.

Other red blood cells were already watching from a safe distance and she saw their disgust and horror at the brutality in front of them. AC did her best to suppress those same sentiments; after all, what alternatives were there, when faced with such deadly invaders? This was something that needed to be done. Sadly AC noticed that her rationalisations didn't quite work even on herself, as she felt her haemoglobin still twisting inside of her, when she so much as glanced at the corpses. Thankfully the cuts were too thin for large organelles to spill out. That was a small blessing.

There were four bloodied neutrophils in total around a couple dead germs and a B-Cell, who was currently talking to two of them, but she immediately recognized the fluffy white hair of one close by, despite 4989 having his back turned to her.

Standing apart from the others he seemed to be dissolving one of the beige coloured germs with his hydrolyzing enzyme spray, and hadn't taken notice of her yet. AC took a deep breath, not feeling as confident as she had a couple minutes ago. Nonetheless, she stepped forth, slowly, hoping not to startle him.

"Uhm, U-4989?" Her voice still sounded too timid, even to her own ears.

The neutrophil turned around, a look of surprise on his face. It kinda felt like a role-reversal. "AC 4293?" He'd clearly not expected to see her and quickly put his spray away, brushing over his clothes with his hands, as if he was trying to clean up. If anything he spread the cytoplasm even more, as well as some mucosa-like substance.

"Yes, hi," AC greeted him, trying her best to smile with semi-success and not to look at the gore. "I brought you something. Just a little thank-you for the bracelets." With so little time, she'd simply gotten a fresh tea and a germ soup, as she didn't know if neutrophils could even eat anything besides germs; rather sad really, if that was the case. Suddenly she wondered if her gift was a little redundant, given that they had just killed several bacteria. Maybe they ate those first? Had this been a mistake?

A little confused at first he looked down, but when he saw her 'presents', his expression brightened.

"Great, thanks." Grateful, he took the cup and container, stacking them carefully, much to AC 4293's delight. At least she hadn't picked wrong then. A short, but awkward, pause followed, before he spoke again. "So, ahem the bracelets. Do they fit? You...like them?" Something like hope flickered in his grey eyes.

Shyly she nodded, lifting her arm to show off her now covered wrist. "Yes; it was very thoughtful. Thank you."

"I was worried, because, you know." He chuckled nervously. "Bracelets." How could anyone so bloodied, look so absolutely innocent at the same time, with such big, bright eyes and sheepish smile?

It actually stunned her for a moment. "Oh," AC whispered, before finally understanding what he meant, her eyes widening. She'd never associated them with the parasite. "Oh no, it's fine; they blend in nicely with my gloves," she quickly reassured him.

He gave a sigh of relief. "Glad to hear." The neutrophil inclined his head a little. "Still afraid of me, huh?"

AC hugged herself tentatively, a part of her indeed still very uncomfortable. "Never really interacted with a white blood cell before. Well aside from the occasional barked order about getting out of the way or something like that," she told him.

Seemingly a little embarrassed his cheeks turned a pale pink, something that she'd never seen before or expected to ever see; it was weirdly adorable. "We're not exactly known for our communication skills," he admitted with a shy laugh.

She looked at the other neutrophils and back to him. "That aggressiveness; is that only when you're around antigens?" The erythrocyte tugged a little at some of her dark, auburn strands. "I'm just asking because you seem nothing like a stereotypical leucocyte." Quickly she bit her lower lip, but it was too late. Had it been rude to say that?

Thankfully he didn't seem offended and merely shrugged. "It varies. I mean just like with every cell population you have a wide range of personalities, but at least with us neutrophils, we all first and foremost want to protect. That's what we were born and trained to do." He gestured to one of the dead germs. "But that means we were also made to kill anything that would harm this body, so when we find a threat, eliminating it with extreme prejudice becomes priority. It's a rush really; it's intense, exciting and it doesn't really stop until you've killed your target. But of course we always know what we're doing."

"So you too get...bloodthirsty?" Somehow that was a little disheartening.

The neutrophil nodded. "Comes with the territory. Plus hesitation can have dire consequences for the body. If only one germ escapes, it could mean the end of our world." He gave her a somewhat self-conscious smile. "But yeah, I go a bit crazy like the others too."

"Oh." This really shouldn't surprise her, but it made her feel uneasy nonetheless. Still, it was foolish; it wasn't like he would suddenly snap.

Suddenly he slapped himself on the forehead, his cap sliding back. "And that wasn't the most reassuring thing I could have said. Sorry." Worriedly, he studied her reaction. "But I would never hurt a healthy cell. I'd sooner jump into stomach acid." He sounded so earnest and his bloodied appearance aside, he looked nothing like a killer; not with that warm smile, those big, friendly eyes and his short, fluffy hair. He just seemed to be a very genial person and her haemoglobin twisted again, but for a different reason.

"No, I'm sorry," AC 4293 told him guiltily, feeling her cheeks flushed. "You've been so nice to me, and I'm acting like this." She felt ashamed to be so judgmental.

"Don't worry, I get it," he told her, but his smile was weaker than usual, almost brittle.

She furrowed her brow. "It doesn't bother you?" Because it seemed like it did.

U-4989 shrugged, but AC was certain that he almost looked...sad. "Well, a little, but none-immune cells always act like that around us. Most anyway." Was he talking about the platelets? They never seemed afraid of the leucocytes from what she'd seen, in fact they often seemed unfazed by their violent occupation.

"Still, I want to try and do better," the young erythrocyte assured him. "So again, sorry and thank you for the bracelets; I really like them."

At this the smile became genuine once more; it really suited him much better. "Glad I could help."

And this time AC managed to smile sincerely in return. "Yeah, so...bye." Lifting a hand, she waved and headed back to the bloodstream to where she'd left her cart. Duty called.

Before she turned around he too waved, looking much happier than he had last time they'd parted ways. "Bye." No, this had absolutely not been a mistake and the knot in her chest was gone again.

Chapter Text

Taking A Step

U-4989 made his way to a little canteen near the heart, squeezing past a group of chatting erythrocytes to get in. They hadn't noticed him at first, yet suddenly all but jumped aside, when they saw the white uniform. The neutrophil mostly ignored them and looked around.

He'd contacted one of his friends and learned that he was taking a break between patrols here, which suited 4989 well, as he was on his way to the head anyway. Easily he spotted his white-clad friend among the red blood cells.

U-1146 and AE 3803 had found themselves a table at the corner of the room, where despite the nearby window they still had some privacy; given their rather unusual relationship that was probably for the best.

To this day they were trying to maintain a low profile, in fact, until recently they had even attempted to hide it from their closest friends. A futile effort of course, considering that the other three neutrophils had secretly helped them get together in the first place, something those two lovebirds actually didn’t know about.

But it wasn’t a secret anymore and frankly you only needed to take a look at them together and you'd know.

Their unique relationship was actually the reason 4989 sought them out today. He required advice, and they were possibly the only two who had some expertise helpful to the fluffy haired neutrophil.

As he approached the table 3803 waved him over, smiling warmly as ever, the neutrophil returning the gesture in kind. "Hi guys."

"Hi, 4989.," the erythrocyte greeted him as he sat down at the opposite side of the table. "How have you been?"

"Pretty well, thanks for asking," he replied, suddenly feeling a bit nervous.

His friend apparently picked up on that. "You said you needed help," 1146 noted. "Everything alright?"

Here goes nothing. "Guys, mind if I asked you for some advice?"

"Advice?" 3803 was perplexed, inclining her head a little.

The other neutrophil however only nodded. "Of course you can. What do you need it on?"

For a second 4989 nibbled on his lower lip, before taking a deep breath. "You remember the first erythrocyte NK removed the Plasmodium from?"

"Of course."

"She's the one, who told you about me, right?" the redhead piped up, looking to her boyfriend.

He smiled and nodded once. "Yes; I can't express how glad I am that she remembered your name."

Frankly, they were all glad that 3803 had survived the ordeal, but 1146 would have naturally taken her death the hardest, even back then, when they hadn't known about their true feelings for each other yet. But today 4989 wanted to talk about AC 4293. "Well, I've kinda been trying…to make friends with her," he explained, hoping his cheeks remained white.

"She was the erythrocyte you talked with the other day after we had fought the Staphylococci and Pneumococci," 1146 realised. "Seems like you've already made some progress" he pointed out, before taking another sip from his tea.

4989 nodded. "A little, but she's still very nervous around me. That common fear towards us leucocytes is really not helping matters." He looked to the erythrocyte, hope flickering in his eyes. "So I was wondering: how did you overcome your fear, 3803?"

She giggled somewhat sheepishly and scratched one of her now lightly flushed cheeks. "Actually I never really was afraid of you white blood cells, except the T-Cells maybe," AE confessed.

Not the answer he had expected. "Never?"

"Well, first time I saw you guys in action I was of course a bit shocked, but I had just been attacked by a germ as well. If Hakkekkyū-san hadn't saved me, I would have died then and there, or later when I was attacked again." She looked at 1146. "Of course I was a bit intimidated, but I was never truly afraid of you."

"Oh." Not the answer 4989 had expected or hoped for.

"I guess that wasn't the answer you were looking for?" AE 3803 concluded correctly, seeing his disappointment.

Quickly he lifted his hands. "Don't take this the wrong way, I'm happy things worked out so well between you two, I really am, but it doesn't exactly help me. I mean I'm looking for anything that could help me ease her fears." He rubbed the back of his head. "I'm not even sure how I should start a conversation with her."

"How did you do it before?" 1146 questioned.

"Well," he chuckled embarrassedly. "The first time around I pretended to have gotten stuck while migrating and asked her to help and pull me out."

His friend frowned, more surprised than disapprovingly. "Really?"

"I didn't want to intimidate her," 4989 quickly defended himself. "It seemed like a good idea at the time. Still, I learned that the scar troubled her, so next time I got her bracelets to hide it."

"That's why you measured my wrist the other day," 3803 exclaimed; admittedly he'd never told her what he'd needed the measurements for; he just hadn't really wanted to tell anyone about his attempts to befriend an erythrocyte until he had anything to show for.

He nodded. "Yep. Thank you again by the way; it was very helpful," 4989 told her with a grateful smile. "Anyway, thing is, I don't know how to continue from here on." He naturally had thought about it, but hadn't managed to come up with anything good. He still wasn't sure if simply walking up to her was a good idea and even if he did, frankly he had nothing beyond "Hi".

"When you happen to meet again, you could ask her about her day; everyone likes it when their work is appreciated," 3803 suggested.

"That is if you mean it," 1146 was quick to add. "I suppose that's the most important part; be honest. If you have to put on an act every time you interact with her, this is not going to work out."

Made sense. That was the whole point after all, to assure her and perhaps one day other erythrocytes that neutrophils and by extension other white blood cells were more than bloodthirsty killers. If he had to act and if she learned that he was being dishonest, any effort would have been for naught. Besides, it wasn't like he needed to pretend anyway. He was interested in learning more about her and he liked to think that he was a rather affable cell…outside of battle anyway.

"Any more tips?" he asked hopefully.

3803 looked to the ceiling as she pondered, a finger tapping her chin. "Well, going all across the body is exhausting work. Sometimes we don't find the time to eat or drink enough on hectic days, so tea and glucose is always appreciated," she mentioned after a while.

Like AC had done for him, bringing him soup. "I guess that could work."

Both 1146 and 3803 continued to try to come up with more suggestions, but eventually only looked at each other, equally empty handed. "I'm sorry we're not much help," his friend told him.

"Truth is I'm not quite sure why things worked out between us like they did," AE 3803 admitted, looking sorry. "They just did I suppose."

4989 however smiled. "No, its fine, but I thought asking you couldn't hurt." A little was still way better than nothing. "Anyway, sorry to take so much of your time."

"Not a problem," the erythrocyte assured him with her cheerful smile.

"Well, you guys have fun now," 4989 told them with a meaningful wink as he stood, ready to depart.

AE blushed, her cheeks suddenly bright red, while 1146 shook his head an amused smile on his lips. "Just go back on patrol; the ears aren't going to guard themselves."

The fluffy haired neutrophil grinned, doing a mock salute. "Gotcha."

"You seem disappointed."

Her friend's words tore AC 4293 from her thoughts and she shrugged. "Finally a delivery to near the brain, but like every other time it has to be during waking hours." She sighed. "I'm never going to see the fireworks during the REM sleep at this rate."

Rapid eye movement sleep

There are five kinds sleep phases, one being REM sleep or REMS, which is distinguished by rapid movement of the eyes and low muscle tone to the point of immobilization, while blood pressure and pulse rise. Even brain activity resembles more that of someone awake and thus most dreams occur during REM sleep as well.

REM sleep phases occur several times a night, accounting for approximately 20 to 25 % of an adult's sleep cycle, and over 50 percent of an infant's, a reason why it's thought to play a role in learning, memory and mood.

"I know it's far, but perhaps you really should use your off time to go see it," FP 1564 suggested.

Since her time as an erythroblast AC had wished to see the brain, when it created dreams; countless neurons firing as they communicated, resulting in a unique lightshow, which could be watched from certain designated viewing areas. From what she had heard these were always packed, but nonetheless she just wanted a chance to see the show and if that meant being squeezed in between her fellow erythrocytes, so be it.

"Yeah, maybe," AC conceded. "It just would have been convenient to combine it with a delivery, you know."

He nodded understandingly. "I know and I'm sure one day you'll be lucky. Until then, you gotta make your own luck." Since she could remember, FP 1564 had always been someone with an adage for any given situation.

So she rolled her eyes, but with a smile. "I thank you for your wise words, senpai."

"Ah, the difference a few minutes make," FP chuckled.

AC shoved him playfully, now a smirk on her lips. "Don't get smug; how many times did you get caught by our neutrophil teacher?" Lessons of running away from an immune-cell, playing the part of a bloodthirsty bacterium were among the more memorable of their childhood.

He quickly cleared his throat and looked away. "Not important." But then he grinned. "Though, if I remember correctly you're the one, who got into trouble for running off."

"Hey, I stayed in the bone."

Her friend chuckled. "Yeah, right into an osteoclast construction site."

"Unimportant details," she deflected, tugging at one of her strands; how could she have known that they had been reconstructing part of the bone nearby?

Seeing her lifted hand, FP 1564 noticed something. "You got a bracelet?"

AC let go of her hair and looked at her wrist. "Oh yes; just something to cover up the scar."

"Guess you finally found something." He'd seen her try out a few options, among them bandages, which sadly had only started to itch after a short time. "Did you make it yourself? Looks like it took a bit of effort to make."

She couldn't help but bit her lower lip. "Actually…it was a gift," AC told him evasively; how would he react, if he learned who had made it for her? Surely not as badly as her other friends, but still.

"A gift? Another one of our classmates?"

"Not exactly."

Her friend seemed mildly surprised. "Are you embarrassed?" Suddenly he grinned. "Ah, is there something more?"

AC's eyes widened, knowing what he was implying. "What! No!" she quickly corrected him, shaking her head. "Nothing like that; I actually hardly know him." In total they might have talked for fifteen, maybe twenty minutes tops.

FP frowned. "Okay…but you don't want to tell me?"

"I…" The erythrocyte sighed; now she couldn't exactly talk herself out of this anymore. She had to tell him something. "Promise you won't tell CT or AD?"

"What?"

"Please?"

He still seemed puzzled but nodded, seeing the pleading look in her eyes. "Alright. So who?"

AC swallowed, tugging at her dark, auburn hair again. "A neutrophil; you know, the one you guys saw when we happened to meet at the nasal cavities."

"The one who helped save you?"

She nodded. "Yeah; when he asked me how I've recovered, I may have mentioned that the scar bothered me. And a few days later he suddenly shows up and gives me two of these." AC looked at the braided bracelet again; she kept the second in her little bag, just in case the one she wore got damaged. Thankfully the material the neutrophil had made them from had proven resilient and didn't itch one bit. Most of the time she didn't even notice that she was wearing anything.

"Is that so?" The broad grin from earlier made its return.

AC frowned. "Are you implying something?"

"You have to admit it's strange that an immune-cell would do such a thing." FP shrugged. "Maybe he thinks you're cute."

But she could only roll her eyes at his suggestion. "Maybe he thinks I'm an easily freaked out erythrocyte. I mean I have made an excellent job proving that recently," AC joked dryly.

"Don't beat yourself up," FP 1564 tried to reassure her with a warm smile, as he placed a hand on her shoulder. "Besides he's a neutrophil; he must see us red blood cells freak out all the time."

True enough. Frankly AC couldn't think of a single red blood cell, who wasn't at least disgusted whenever they saw bloodied leucocytes and admittedly most ran away screaming at the mere sight of bacteria or other invaders.

"So you think there is more behind this than a friendly little gesture?" she asked her friend, shaking her wrist a little for emphasis.

"Merely alluding to the possibility," FP clarified. "I mean he didn't just give you two ribbons to tie around your wrists."

Truthfully AC wasn't entirely convinced, and she frowned sceptically. "I don't know. Our conversations were rather brief."

"What did you talk about?"

"He asked me about my recovery, whether I liked the bracelets…" For a moment she paused that feeling of guilt emerging, just like when she had last talk to the neutrophil. "If I was afraid of him."

"Are you?"

AC couldn't help it, but when she thought back to that neutrophil, she always remembered him with that warm smile. "I think afraid is too strong a word. Uneasy, sure, but as far as white blood cells go, I'm not exactly frightened by him." Her eyes narrowed questioningly. "You seem awfully alright with me talking to a leucocyte."

He gave her a wry smile. "I'd be lying if I said that I wasn't uncomfortable around them as well; their main function is to kill after all, even cells of this body if need be. However, given what you've been telling me, I don't think you're in any immediate danger. But, I can see why you don't want the others to know about this."

"They would freak out." She knew they meant well and were just being protective, but it was nonetheless annoying at times. Even now when she was just tired from running around the body without a break for a long time, they got overly nervous, as if she could collapse and die any moment. If they saw her so much as interacting with a leucocyte, they would probably full on panic.

FP 1564 however chuckled, as if he found that prospect actually amusing. "AD would probably burn those bracelets, while CT would cut your hair and give you a makeover to make you unrecognizable."

Protectively she swiftly grabbed the long tail. "No one's touching my braid!"

FP nodded, remembering a few incidents during their childhood, when some blasts had pulled at it in an attempt to annoy her. It had not been worth it; she'd never been someone, who just put up with anyone’s nonsense. "Oh, I'm well aware." But he suddenly became more serious and AC saw a hint of worry in his eyes. "Still, be careful, alright? You never quite know with leucocytes."

AC didn't reply, admittedly feeling conflicted. White blood cells were dangerous, sure, it was their job to kill after all. But unpredictable? They targeted invaders and cells that had become a threat to the body only; that actually was extremely predictable. She thought back to her last conversation with that fluffy haired neutrophil and those bright, friendly eyes. No, as long as she was a healthy erythrocyte, she was certain that they would never be glaring at her with murderous intent.

The ear really didn't guard itself.

Erythrocytes and common cells hid or ran away screaming, as a germ fled through the blood vessels around the middle ear. Its primarily orange and grey body was shaped like a caterpillar, yet moved as swiftly as a snake, barging through the street, pushing aside any road signs, benches and even some of the slim trees distributed sparingly in the area. And U-4989 was following close behind.

His receptor was ringing obnoxiously loud in his ears, but he was more focused on the antigen running for its life. Until finally the germ was not in close proximity to any civilians for a moment. Immediately 4989 reached for his throwing knives, launching a handful at the invader.

It screeched in agony as they imbedded themselves into its back, reeling at the same time, causing the germ to crash against the wall of a nearby building. Grinning triumphantly, 4989 lifted his blade, ready to deal the finishing blow.

In that moment the bacterium whirled around, its beady eyes full of fear, its beak-like mouth clicking. "Neutrophil! Shouldn't you be at the respiratory tract, taking care of those Pneumococci?" it cried desperately, squirming and writhing, clearly searching for a way out.

"Your competitors? They've all long been taken care of, germ. But you've made the mistake of getting into this body, Haemophilus."

Haemophilus influenza

A bacterium that was once believed to cause influenza, until the responsible virus was discovered. Types of this bacterium without capsule are part of the normal human mucosal flora and are usually of no concern. Encapsulated Haemophilus however are obligatory pathogenic bacteria, divided into serotypes A-F, with type B being the most notable. They are especially dangerous to children and can among others cause meningitis, epiglottitis, otitis media, sinusitis, bronchitis as well as pneumonia, which is why vaccination is recommended

"No!" With sudden, unexpected speed, the bacterium threw itself at the neutrophil.

"What?!" Utterly taken by surprise, 4989 quickly lifted his knife, blocking the beak aimed for his face, letting it bite down on the flat sides of the blade instead. The weight of the bacterium threw him off his feet however and just as his back hit the ground, the Haemophilus tossed its head around, actually managing to tear the weapon out of the leucocyte's hand. Oh, come on! This was just embarrassing now.

The beak came down again, the tip once more going for his face. Baring his teeth, 4989 caught it just in time, one hand at the beak, the other pressed against its face. Stalemate. Maybe if he kicked it hard enough he could safely draw another knife.

"Neutrophil!" Who? He knew that voice, but at this moment couldn't tell who it belonged to. More importantly he heard a blade slide across the ground and from the corner of his eye saw his knife coming to a halt in arm's reach. Yes!

4989 delivered a powerful kick into the germ's belly, making it flinch, and reached for his knife, his other hand still holding the beak at bay. "Die, germ!" and he rammed the blade into its head.

"Arrgh!" The Haemophilus twitched, and he felt it go limp, allowing him to finally throw it off. With another wide slice, he opened up its belly, making sure it would not get up again.

As the receptor deactivated 4989 sat up, feeling himself relax a little while he caught his breath, with the bloodlust draining away as quickly as it had come. Not his best kill, but at least it was done.

The neutrophil turned his head, when he noticed someone approaching him and quickly realised that it was an erythrocyte. His eyes widened, once he looked up to see her face. "AC 4293?"

The auburn-haired cell crouched down next to him, a basket with nutrients dangling at her arm. "You're alright?"

"What?" 4989 stared blankly at her, not sure if he had misheard. But he saw the genuinely concerned expression and quickly recovered, his mitochondria fluttering. She cared? Swiftly, and absolutely elated, he jumped back on his feet. "Yeah, just a few bruises. Great timing with the knife by the way; thanks."

"You're welcome," she replied as she rose with a tentative smile. "Glad I could help."

Finally getting a good look at her, 4989 noticed that her shirt was almost as red as her jacket, not to mention several more red splashes across her arms and legs. Had his last slash…? Suddenly feeling a little guilty, he bashfully rubbed the back of his head. "Looks like you got quite a bit of cytoplasm on you. Do you want me to show you to a wash station?"

"I suppose that would be for the best," she conceded, regarding her appearance critically. "I'd be getting some odd looks with all this on me."

Rather relieved at her decision, and how well she took being splattered with cytoplasm, 4989 smiled. "Great; I'll just be quickly dissolving this germ and we can get on our way."

"What was that anyway?" she asked, looking over his shoulder as he recovered his throwing knives from the body. Fortunately, they were all still in good condition.

"Haemophilus influenza," he explained as he pulled out the hydrolyzing enzyme spray and began to dissolve the bacterium. "This one was really only a nuisance, but its encapsulated relatives are tougher to kill and could have caused an inflammation here at the middle ear."

"Sounds nasty."

The fluffy haired neutrophil nodded, watching the body simply melt away. "They are and if left to their own devices they could do more damage, perhaps even destroy this world." After a few short minutes, the entire germ was gone, leaving only a damp spot on the street that would in dry time. Satisfied 4989 put the spray away again and turned to the erythrocyte, who had patiently waited. "Ready to go?"

She gave him a single nod. "Lead the way."

Together they started walking down the road and the fluffy haired neutrophil noticed that they both were trying to avoid looking at each other. He could feel the awkwardness lingering between them, as well as his growing urge to disperse it. He had to say something. Hadn't AE 3803 suggested something? "So, um…how was your day?" 4989 tried carefully, his cheeks warming.

"Huh?"

Upon hearing her confusion, he blushed, well, as much as a neutrophil could anyway. He wanted to migrate straight through the floor, as apparently the damn thing refused to swallow him up. It sounded so clunky. What had he been thinking?

"Oh, I…I've been well?" He could hear her uncertainty and strangely enough it was a bit comforting for him to know that she was on a learning curve just like him. Maybe it at least made him appear like less of a fool to her. "Thanks for asking."

His lips curved up into a timid smile; he could salvage this. "Glad to hear. Sorry again for the cytoplasm."

Surprisingly she shook her head. "Don't be, it was my bad. I'm the idiot, who didn't take a step back." AC 4293 pulled a little at her clothes. "Well, at least it doesn't show on my jacket."

"And now the shirt matches," 4989 pointed out, hoping to lighten the mood.

For a moment she looked at her attire. "I suppose being a red blood cell and all, I can finally fully live up to the designation." Was he detecting a sense of humour?

Feeling emboldened he decided to reply. "Don't know; those blue shorts kinda stick out." He tried to joke.

"Ah, true," she replied, obviously only acting disappointed.

His smile grew genuine, delighted to have gotten a glimpse at her more mirthful side. Now that he could work with. "Hey, what am I supposed to say? I'm obligated to dress in all white, when my function is to eliminate all threats to this body." He tugged at his own jacket. "Now every time I do my job I look like someone's tossed a bucket of paint at me."

AC 4293 inclined her head. "You think it would be better if you dressed in red?"

The fluffy haired neutrophil merely shrugged. "Well, at least it wouldn't be so noticeable; and trust me, white shows everything, not just cytoplasm."

"I can imagine."

…

Okay, this was not something she had planned on today. Of course she had expected to meet this neutrophil again, just not so soon and like this. But when she'd seen him struggle with that germ, his weapon in front of her feet, how could she not have acted?

Still, just walking down the road with him seemed…weird. The looks other erythrocytes gave them, probably in part because of the cytoplasm on her, weren't exactly helping.

Thankfully U-4989 seemed just as flustered as her, which admittedly eased her mind, especially when he started making jokes. The tension she'd been feeling actually lessened as they walked, even if she didn't entirely relax.

They continued to follow the road for a few blocks, until the fluffy haired neutrophil pointed to a doorway with a staircase leading down. "Here we are," he told her and they stepped inside what she could only describe as a communal shower. "You can leave the basket here at the entry; I believe the cell would be happy if his sandwich didn't get soaked."

Probably a good idea. "Alright." She placed her basket on the stairs and followed him down.

There were several hoses, some with showerheads, some without, while along the wall were shelves filled with shampoo and white towels, which looked surprisingly soft. She kinda wanted to touch one, but AC had a feeling she would need one soon enough anyway.

So instead, she sat down on one of the stools next to the neutrophil, who handed her a showerhead, with a worryingly apologetic smile. "Here." Tentatively she took it and turned it on. "Careful, it's…"

"Ah! This really is cold." Why hadn't she heard him out? She hadn't felt anything this cold since that snowstorm during the hypovolemic shock, and she shut her eyes immediately, shuddering.

"Sorry." AC heard him apologize. "Not a fan myself, but I'm afraid I really can't do anything about it."

"It's fine." Actually it was incredibly uncomfortable, but unfortunately there wasn't exactly an alternative. "You do this daily?" she asked, opening her eyes, both curious, but also trying to distract herself.

"On average at least once. Always depends on how many germs I encounter," the fluffy haired neutrophil explained, having started cleaning himself as well. Actually, he seemed almost unbothered by the cold. Maybe that was just by comparison though.

She couldn't help but feel sorry; as if having to fight and eat germs wasn't bad enough. "I think I would have frozen to death by now."

He chuckled, making her glance over to him again. "Softie."

It was an impulse, a spur of the moment thing, but without thinking she turned her showerhead. And the water stream hit him right in the face.

AC gasped, hands flying to her mouth, eyes widened in shock. The showerhead fell soundly to the floor. Why had she done that?

The neutrophil spat out some water, trying to wipe of the rest from his face. Nervously she watched as he blinked several times, clearing his vision. For a moment he stared at her, clearly staggered. Was he mad?

And then he laughed, loud and brightly.

Now it was her turn to look taken aback. She was still frozen in place, when he took his own showerhead and pointed it at her. "You're on."

"Eeh!" AC screamed when the cold water hit her, and she quickly covered her face using her arms.

She could hear him chuckle as he lowered the showerhead again."Giving up already?" the neutrophil asked; she could practically hear him grinning.

That sparked something in her. "Oh, you wish." And hit him again with the water, face still turned away from him.

She only heard him laughing, merry, carefree and she couldn't help but laugh herself; it was infectious. U-4989 tried to circle around her, hit the face she so desperately tried to hide with one arm, while she tried to hit him as well, never daring more than brief glances, catching glimpses of his wide grin and bright eyes.

Suddenly she didn't feel the cold anymore. Sure her cool cheeks were flushed, but she was laughing, running and sometimes slipping, while she fought water with water. It was strange, but for a moment she felt like an erythroblast again, despite being soaked with freezing water.

AC had no idea how long they continued, until she heard steps on the staircase and a male voice spoke up. "What is…?" But he was interrupted by a spurt hitting him straight in the face.

"Ups; sorry 2048," U-4989 chuckled.

Said leucocyte wiped the water from his face. "You two seem to be having fun," he noted, thankfully smiling. He too was a neutrophil, with a hairstyle not dissimilar to U-4989, though his hair was perfectly straight, while his eyes were a bit narrower in shape.

"Care to join in?" the fluffy haired neutrophil asked, waving with his currently turned-off showerhead.

The newcomer shook his head. "Not really, I was just wondering what this commotion was all about."

"Ah come one, don't be boring," another neutrophil behind him remarked, his eyes completely covered by bangs, just before giving his colleague a push.

The one called U-2048 slipped across the wet floor, struggling to retain his balance and grabbed one of the hoses without a showerhead. "Now you've both done it."

And the battle began in earnest. With three neutrophils doing their best B-cell impersonations, AC completely lost track of what was going on. Not that she cared. Over the loud noise of rushing water, she could still hear laughter, including her own, as she blindly pointed her showerhead to wherever the streams hitting her came from.

Eventually, the attacks stopped coming in, and she dared to open her eyes, her clothes feeling heavy, clinging to her body, same as her hair. Apparently there were only two combatants left and she turned off her showerhead, taking a deep breath.

She saw the straight-haired neutrophil approach her. "You're alright?" he asked her politely.

"Just a bit out of breath." AC confessed, panting a little, feeling the cold return to her body, as well as some of her earlier nervousness. Still, she was pretty sure she'd seen this one before with U-4989; that along with him having participated in their game right now at least meant that he couldn't be such a bad guy either.

Meanwhile, the neutrophil nodded towards his colleague. "Hope he isn't getting on your nerves too much."

"He's not," she assured U-2048. "I actually had a lot of fun." As strange as it was to say, now that she'd regained her sense, but it was true. This had been great. Seriously, who would have thought?

Both of them looked to the other side of the wash station, where U-4989 and the other neutrophil were deciding a final battle, until the fluffy haired leucocyte slipped and fell. His friend laughed and would have probably declared himself the victor, if the hose of U-4989's showerhead hadn't knocked him down in that moment, since it had wrapped itself around his legs during their playful tussle.

U-2048 and AC chuckled at the sight. "Well, if the fun ever gets too much, don't hesitate to tell us. We'll get him off your back, don't you worry."

"Thanks."

He inclined his head, studying her for a second. "Would you like to join us for a tea? I know I always need one after a shower and we're all a bit soaked." Apparently, he had noticed her shivering quite a bit.

Where all neutrophils this attentive? "That actually would be nice." She looked down at her trembling hands, wondering if she should wring out her gloves. "I think my fingers are a bit stiff."

"We can fix that," the one called U-2626 replied grinning as he joined them. "Hey 4989, you're coming?"

"Hang on a second," the fluffy haired neutrophil replied, picking something up from the ground, already carrying something else under his arm. "Lost my cap there for a second."

"Shame on you." His friend teased.

4989 merely stuck his tongue out, only to chuckle a moment later. With a happy smile he then turned to AC and handed her one of the towels he must have picked up before coming over. "Here; thought you might like one."

Even after only having spent a little time with these neutrophils, AC had to admit that they were surprisingly pleasant company.

To her they were actually very courteous, not only serving the erythrocyte tea, but U-2626 offered to get her some glucose, despite the next vending machine being a few streets away.

When talking with one another, they were also quite casual and laid-back, a far cry from the lymphocytes, especially the Killer T-Cells.

They reminded her so much of the myelocytes she'd seen back in the bone marrow, making jokes, teasing each other, though thankfully they weren't playing catch with drawn knives and yelling about killing stuff. Still, she had no problem seeing that these three had been life-long friends and she found herself smiling the entire time, listening to them, though still timid whenever they addressed her directly. After all, despite their kindness, she had only just met them and so her mind was racing, trying to find out how to act around them.

Nonetheless, why had she been so scared all this time? It suddenly seemed so ridiculous.

Eventually however, both U-2048 and U-2626 departed, having to resume their patrol, leaving AC alone together with U-4989.

"Feeling better?" he asked after waving goodbye to his friends. "Um, I mean warmer?"

And apparently he was back to acting awkwardly; not that she minded, given that he more or less mirrored her own insecurity again. "Yes, the tea really helped. Thanks. But I guess I should be getting back to work myself." She probably had lost way too much time already, but if she walked with a swift pace, she certainly could make up for most of it.

Amusingly, U-4989 eyes widened, as if he'd only just remembered that she had her own duties to attend to. "Oh, of course!" Sheepishly he rubbed the back of his head. "Again, sorry for…" But he was interrupted by a shout.

"AC!"

Surprised both of them turned around and the erythrocyte recognized one of her friends running towards them. "CT?"

Her short-haired friend all but crashed into her, throwing an arm around her shoulders, the handle of her card in the other hand. "There you are, we've wondered where you've been."

"What?" She could feel her friend pushing, and perplexed as she was by CT's sudden arrival, the red blood cell simply stumbled along with her.

"Come on, all this oxygen isn't going to deliver itself," the other erythrocyte insisted, now all but dragging AC with her. As a matter of fact CT had always been the strongest of them, despite being the shortest by half a head, making it difficult to resist.

AC managed to briefly glance back, only to see U-4989 disappointed expression and sagging shoulders. Her haemoglobin felt like it was twisting uncomfortably in her chest at the sight. This was not the goodbye she had had in mind.

For a moment she considered resisting CT, but then it occurred to her why her friend was acting so strangely. No, she would have to wait until they were alone and then try to explain everything.

And so AC let herself get dragged away, down the road and around another corner. Just to be safe. "CT I'm fine," the auburn haired erythrocyte finally declared, slowing down to a stop. "You can let go of me now."

Clearly worried her friend studied her, but thankfully removed her arm from AC's shoulders. "You're sure? That was a leucocyte," she noted troubled, pointing the direction they had come from.

AC couldn't help but sigh and lifted her hands, hoping to reassure her friend. "I know, but it's fine. A little earlier I was around when he finished a bacterium and got some cytoplasm on me." Maybe for now it was for the best not to mention the shenanigans at the wash station or her tea-time with neutrophils.

"Is that why your clothes are a bit damp?"

She nodded. "Yes; I think he was just about to apologize for that again." Third times the charm, right? Unnecessary, though it was sweet of him. "That's it. Promise."

"Oh…" CT's dark eyes widened, and she covered her mouth with both hands, clearly embarrassed. "Sorry, guess I got carried away," she admitted guiltily.

"It's fine." AC chuckled, glad that things were now cleared up. Still, this was exactly why she didn't even want them to know about the bracelets. Her eyes wandered to the cart beside them. "You're going back to the lungs?"

The raven-haired erythrocyte nodded. "Yes, just made my delivery. I was thinking about getting some dinner from the booths at the pulmonary vein. Care to join me?" she offered.

"I still got to deliver these nutrients." AC told her, lifting the basket. "But hey, I'm gonna hurry up and meet you there, alright?" And there was something else she needed to do first; hopefully, it wasn't too late.

"Great, see you later."

...

Heavy-heartedly 4989 watched the two erythrocytes disappear in the crowd of cells. And that after things had developed so well, better than he had honestly expected. After all, today had been the first time he'd seen her laughing, brightly even, despite her freezing, with a face as red as her jacket from the cold water. Sure AE 3803 suggestion, asking about her day, hadn't exactly worked, but he'd winged it afterwards.

He was still delighted how well she had responded to his cautious attempts at humour and then the battle in the wash-station. Frankly, she'd kinda started it…and he couldn't be happier. He'd never seen her so relaxed. Only afterwards, when they had all warmed up with some tea she'd been a lot more coy again, hardly speaking, mostly just listening to them talking. However, given that she'd been with three neutrophils, two of whom she'd only just met, things had went surprisingly well.

All in all he was actually satisfied. If only her friend hadn't shown up when she had.

The fluffy haired neutrophil sighed and started to walk. He too had to return to his duties, finish his patrol…

"U-4989!" Hang on.

The neutrophil turned around, seeing the auburn-haired erythrocyte running towards him. She'd come back? "AC 4293?" He was confused, but at the same time so glad to see her. "I thought you had to finish your delivery?" As a matter of fact the basket was still dangling from her arm.

"Yes, but I had to speak with you first, after we got interrupted," she explained, shifting her weight nervously from one foot to the other.

"Huh?"

"Look, I'm so sorry about my friend," she began apologetically, one hand placed on her chest. "It's just, she, like most of my friends, has always been uncomfortable with white blood cells, and since the Plasmodium-invasion and what happened with the NK cell she's a little afraid for me, especially with a leucocyte keeping me company."

"Oh, right," 4989 replied somewhat lowly. Even though he wasn't a NK cell, as a matter of fact, he and 1146 had stood up to her; this wasn't fair.

Meanwhile AC 4293 studied him for a moment. "U-4989, can I ask you something?" she finally asked.

"Sure."

"The bracelets." A finger brushed over the one hiding her scar, but she kept looking at him somewhat quizzically. "Why did you make them for me? You didn't know me."

"Oh. How can I say this…" He took a deep breath. Just tell her the truth, right? "You obviously know how most erythrocytes get real jumpy around us."

"Yes," she replied, looking away, clearly a little embarrassed.

"Well, it's always been like that; I've gotten used to it, whether I like it or not." Briefly the corners of his mouth lifted for a nervous smile. "But then a friend of mine met an erythrocyte, who wasn't afraid of us. They became close friends, and I figured things actually didn’t have to be like that after all." He gulped, desperately searching for the right words. "When...when you thanked me for helping you, I thought…I thought it was worth a try. And when you told me about your scar I just wanted to help, especially after I wasn't able to do much against the parasite itself." 4989 felt his cheeks heating up. "And...and I was hoping to get another chance to talk with you."

There was a brief pause. "I guess it worked."

Hope sparked in him, making his chest feel lighter. "Yeah." There was an awkward pause, both smiling timidly at each other and 4989 struggled to find something to say; preferably a sentence with more than a single word.

To his surprise, AC 4293 however was the first to speak. "U-4989…I really had fun today."

Now that made his mitochondria jump. "Really?" he asked relieved. "I wasn't sure. I was a little afraid that three neutrophils at once might have been a bit too much."

She shook her head. "No, it was actually fine," the erythrocyte assured him, if somewhat hastily. "Thank you."

4989 just wanted to exult, but forced himself to stay still, despite feeling like a compressed coil spring. "So,…see you around?"

AC 4293, still displaying that adorably shy smile, brushed a strand of auburn hair behind her ear. "I hope so."

She never saw him jump, fist raised triumphantly in the air, cheering out loud, much to the bemusement of the other cells around him, as soon as she was out of view and 4989 resumed his patrol a few minutes later.

Chapter Text

Splinter

"I spy something that begins with…"

"Balcony," AC 4293 promptly answered.

"Hey, how did you…?"

She gave him a meaningful look. "Because we had 'endothelial cell' last time and before that it was 'window'."

"Yeah, this street doesn't really impress with variety," FP 1564 admitted and sighed.

"That's an artery for you." AC reminded him, but then shrugged. "At least we're almost at the foot now."

"Yeah. Hey, how about a break before we head back up the vein?" he suggested.

"Oh, definitively."

The two erythrocytes had been walking together ever since meeting at the lungs and now found themselves around the ankle. Both carried deliveries for cells of the left foot and due to it being such a long way down, they needed to follow some of the major arteries, the highways among the blood vessels, which was a bit of a shame, given that most of the interesting sights of the body could usually be found at the smaller ones. Here in this area apartment building simply followed after apartment building. In AC's mind, not exactly the definition of riveting.

Aside from being somewhat boring, the journey as a whole was also a quite tiresome, especially the return trip. Before starting their trek all the way back up through the vein, most erythrocytes enjoyed a bit of rest; AC and FP were no exception. Shame there weren't steam baths at the feet like those at the nose though. Still, after such a long walk, she would happily settle for a bench.

For now however, they simply continued on until they reached the heel. FP waited on the street with both their carts, while AC made her delivery and collected the CO2. One down, one to go.

"I think it's down that way," FP muttered to himself, eyes on the map. He looked up, checking the roads around them. "Ah, yes. Only a few blocks now. "

"Good, I could really use some glucose about now." Hopefully, there was a vending machine somewhere nearby, not to mention that her feet were hurting.

But they had hardly gone a few steps, just turned around a corner, when suddenly the world shook. AC clung to her cart, struggling to stay on her feet same as everyone around her, some stumbling to the ground. It only lasted seconds, before just as sudden as it had started, the trembling stopped again.

"What was that?" FP asked troubled, looking around.

AC, however, didn't really hear him, distracted by something else up ahead. "Look! Over there! "

Down the road was an area where buildings had either partially or completely collapsed, smoke rising from the rubble. Most striking perhaps was what appeared to be a mountain at the centre of it all.

Both erythrocytes hurried down the street, trying to find out what had just happened and what this strange, foreign object was, which could not possibly be something of the body itself. It was strange; usually when coming across an injurythere were craters, holes, but this timethere was something coming out of the ground, looking brown and somewhat fibrous, and it had simply pushed any buildings in its way aside.

"Where did this come from?" FP 1564 whispered, when they had reached the edge of the destroyed area.

Cells were emerging from the rubble , platelets gathered, ready to repair what they could , but in the first moments of arrival , the two erythrocytes could only stare in awe . It just looked so unreal.

"Help!" The faint plea caught AC's attention, FP still staring at the mountain. It had come from somewhere further up ahead. Her eyes scanned the debris, until somewhere in the distance she spotted a small waving hand between the stones.

"Hang on!" And she jumped down from the street into the field of ruins. On her way she crossed small trenches created by the tearing and compressing of the endothelial cells, before rushing up the slope at the foot of the mountain , almost jumping from rubble to rubble . Some pieces gave way beneath her feet, but she was quick enough to avoid losing balance. Footsteps behind her told the auburn haired erythrocyte that FP was following her.

"Help!" This time she heard it loud and clear.

Finally, they reached the cell, trapped in the ruins of his home. "We're here! Just a second, " AC assured him and took hold of a piece of rubble that blocked the hole. While she pulled, FP used his shoulder to push against it. At first it merely swayed, until it toppled and the two erythrocytes simply let it roll downhill.

She heard coughing and from the now widened hole a young, black haired cell appeared, covered with dust. "Thanks," he panted as soon as he was outside, before taking a deep breath. He looked around confused , taking in the scene before him, until he finally noticed the mountain , his eyes widening "Is that…? "

"I… I think that's a splinter, " FP 1564 muttered.

AC felt a shiver going down her spine. "From the outside? Doesn't that mean…? " As if to answer her unfinished question, they heard distant, cold laughter and fearful screams of other cells.

"Oh, no." FP grabbed her by the shoulder, pulling the normal cell to his feet with his other hand. "Quick we have to get away from here!"

Even faster than before the threeran down the slope, AC having to slow down occasionally to avoidstumbling over her own feet. And then she heard it just behind her. "Look what we have here."

"AH!" AC leaped forth, straight down into a trench , hearing something like a claw hitting and smashing a piece of debris , probably where she had just been. Too close! She rolled, ready to keep running, when she spotted a white silhouette dash past her.

"Die bacteria scum!" She dared to glance over her shoulder and watched relieved how a neutrophil slice up a pink germ, a streptococcus, cytoplasm spraying. Saved.

At least for the moment, because AC could already see more bacteria emerging from around the splinter in all shapes and colours. And from somewhere behind her, she heard the distinct sound of numerous receptors activating. Hastily she waved over to FP and the normal cell. "Quick! Down there! " They were right between the fronts, in the middle of what would turn into a battlefield any moment!

Both didn't hesitate to follow her advice and took cover by her side, just before numerous neutrophils leaped over the trench, eager to engage the enemy. "Think we can make it to that road?" the cell asked nervously, catching his breath, fearfully pressing himself against the trench's slope.

"Across a battlefield?" Quickly FP shook his head. "I think we should wait. The white blood cells might get this soon under control. " He was probably correct; right now they might only get caught in the crossfire or  run into another bacterium.

Still, they heard more screams of dying bacteria, roars and shouts by the leucocyte fighting them. From their little trench AC could see more bright red spouts. "I think I'll never again complain about how plain blood vessels are," she noted; this was certainly not what had been in her mind, when she had wished for something interesting to happen.

FP gave her a wry smile. "We know you will."

She shrugged. "Didn't you once say: 'It's the thought that counts'? "

"Sounds like something I would say," her friend admitted, before suddenly craning his neck, a questioning frown on his face. "Is that a B-Cell?"

AC lifted her head as well. There was indeed one of the blue-clad cells, large cannon in hand and despite not having done anything yet, he was smiling triumphantly, or at least confidently. AC could read IgM on his weapon. "Well, the splinter went through the skin; maybe a dendritic cell notified him. Or he just happened to be around. " In either case, she wasn't about to complain.

"Let's keep our heads down."

The sounds of battle continued on, with no side relenting as it seemed. Could it be that as long as the splinter was inside, the platelets couldn't close the wound properly, allowing new germs to constantly swarm in? If that was the case, how long would this battle last?

Eventually, another blue-clad cell jumped across the trench. "Got the IgG!" he shouted, joining his colleague.

"About time; the neutrophils need all the help they can get," the first one replied, still firing from an elevated position near the erythrocytes.

Immunoglobulins: IgG and IgM Antibodies

There are different classes of immunoglobulins (Ig,) also known as antibodies, fulfilling different roles as part of the immune response. They are Y-shaped proteins, primarily produced by B-lymphocytes and plasma cells and can be found in bodily fluids or on the membranes of certain cells.

Immunoglobulin G (IgG) is the most common, making up 75% of all Igs in the serum. Their main functions are complement activation and agglutination, as well as opsonisation.

Immunoglobulin M (IgM) is a larger protein, having a pentameric structure in serum (five 'Y' forming an almost snowflake-like shape), but monomeric on the membranes of B-lymphocytes. They are the best Igs at complement activation, but can also cause agglutination and neutralise toxins. They are also important in the initial/primary immune response, before sufficient amounts of specialized IgGs have been produced.

AC could hear the bacteria again. "Ah, I'm melting!" one screamed in agony, in its last moments before death.

"Ha; complement activation for the win!" the first B-Cell cheered.

Then she heard others. "Get away from me!"

"I can't; we're stuck!"

Craning her neck, AC saw the second blue-clad cell grinning as well. "Looks like the IgG works too."

Agglutination

Antibodies fulfil several functions, one of them being agglutination. They attach themselves to cell membranes, like those of bacteria, connecting them, causing them to clump together/agglutinate. This helps with their disposal through leucocytes.

This however can also happen to cells of the body; when for example the wrong blood type is transfused, antibodies will agglutinate red blood cells, leading to haemolysis.

"Still, this could go on forever if the splinter stays," he continued. Well, that confirmed AC's suspicion and it didn't exactly cheer her up.

"Well, until it's gone, we have to try and hold the line here," the first B-Cell simply replied and resumed fire.

Suddenly she felt a hand on her shoulder. "It's now or never," FP told her and the cell boy. "Let's go!"

AC nodded and jumped back to her feet, climbing out of the trench as quickly as possible. Dead bodies were now lying everywhere; sliced up, some looking as if they were glued together, others partially melted. You had to admit, the immune cells were incredibly effective, if gruesome.

They had made it halfway back to the un-ruined part of the foot, when the ground shook anew.

"Oh, come on! What now! " AC couldn't help but exclaim , both alarmed and annoyed, as she and her friend stopped in order to remain on their feet , while the normal cell boy just continued running despite stumbling and falling more than once.

"The splinter!" FP shouted. "It's getting pulled out!"

The auburn haired erythrocyte looked behind her. Her friend was right; the mountain trembled and ever so slowly retreated. Something or someone was removing it! They had to hurry, or the drag would pull them out! "Run!"

FP didn't need to be told twice, and they picked up the pace. The cell boy proved surprisingly fast, but then again he hadn't spent most of his day walking down almost the entire length of this body and had never stopped to look back. To her distress, AC could feel her legs protest, tired from all the walking and her last meal had been at the chest. She gritted her teeth. Oh no, not like this. She would not go out like this.

Then a new noise caught her attention, not the sound of battle or blood flowing out a wound. It was a rushing sound and once more, she dared to glance over her shoulder "Water?! " The splinter was gone, but instead of everyone getting sucked out the created hole, water streamed through it. No, it was more like a tidal wave flooding the area. The wound was being cleaned! It would wash everyone it caught out!

"The staircase! Hurry! " FP yelled and she could see the same panic that she felt clawing into her chest in his eyes.

But she also saw what he meant, a flight of steps leading to hopefully safer, higher ground. The cell boy reached it first and ran up as fast as he could, practically on all fours. AC could hear the water closing in, desperately pushing herself harder, ignoring her protesting legs. There! She'd reached it!

Quickly AC rushed up a couple of steps and wrapped one arm around the balustrade, reaching out with her other hand, screaming with all she had. "FP!" The water was right behind him; soon it would reach his feet! They would never make it up the stairs in time! "FP! Hand! "

He too reached out. "A…!" The moment their hands touched, the water reached him. It overtook him.

She felt his hand grasping hers; she clung to it, pulled. And felt it slip from her grasp.

His beret disappeared between the waves. AC was forced to take a deep breath, getting submerged as well. She wrapped her arms and legs around the balustrade, desperately holding on, the water tearing at her like some ravenous beast, rushing in her ears like a thunderstorm. With every bit of strength she had left, AC held on. That was all she could do, hold on and wait.

And finally the water receded again. AC gasped for air, panting, but didn't let go of the balustrade immediately. Her body was completely tense, her initial movements awkward and stiff. Eventually, she managed to loosen her grip and simply slumped down to the stairs, shivering from the cold.

The water was gone. Cowering there on the steps she stared down at her hand, now only holding a single empty, white glove. FP was…

…FP was gone.

She searched. AC 4293 searched the area, shouted his name, her voice growing shakier and quieter each time as the realisation of what had happened slowly sunk in. There were no more cells. Only those who had run had survived, or others like the neutrophils, who had managed to hang on with their L-selectin. Everyone else was gone, cells and bacteria alike. It was so eerily quiet now with the wound closed. Like a graveyard.

Eventually, AC wandered off. She couldn't stay. Her mind was utterly blank, yet her body moved, slowly, almost automatically, but it moved. She had to keep going. She couldn't stay, not here. Not here. Her work, yes, she had to do her job, right?

AC didn't know how, but somehow she managed to find a CO2 box and a cart which hadn't been washed away. She doubted the box was hers, but that didn't matter. It needed to be brought to the lungs anyway. Just keep going.

Slowly she walked along the vein. She had to get back to the torso. Heart, lungs and to the next client. On and on. She didn't really register anything around her; sounds were dulled, as if they were coming from far away or from behind a wall and her eyes were vacantly staring at her cart.

"Red Blood Cell? Are you alright?"

She blinked and stopped, suddenly awakening from her trance-like state, finding herself staring at a white neutrophil uniform just beside her. Lifting her head slowly she found herself looking at U-4989, meeting his worried, grey eyes. Somehow the erythrocyte managed to open her mouth, but failed to make any sound, much less form words. She felt…empty. She only felt tears gathering in her eyes.

None of that escaped his notice. "AC 4293, what happened? You're soaked." He reached out, but hesitated to actually touch her. "Are you hurt?"

She couldn't answer. She just couldn't speak. So instead, she let go of the cart and merely lowered her gaze to the lone glove still in her hand. She'd been clutching it the entire time.

"AC 4293?" This time his voice was lower, but sounded no less worried.

And finally she was able to summon her shaky voice. "FP…we were making our deliveries…there was that splinter…water…got pulled out." A first tear rolled down her check, her body started to tremble. "I managed to get to the stairs…I reached out but, but…he was washed away…he just slipped through my fingers, he…" And AC simply broke down.

A storm of emotions finally descended upon her mind and soul, tearing everything down, anything that had kept her standing until now, and shecried like shenever had before in her life, her visionsimplygone in an instant. FP 1564 was dead; her best childhood friend gone, ripped away.She hadn't been able to help him.She'd failed him.

Just when she was ready to collapse, a pair of strong arms wrapped themselves securely around her and she was pulled against a much sturdier body than her own. Her beret slipped back when she pressed her head against his chest , one of her hands covering her mouth as she wept the other holding on to the white uniform, clutching desperately the fabric .

U-4989 didn't say anything; he simply held her and let her cry, one hand rubbing soothingly over her back, the other cradling her head.

                                                                       

AC didn't know how long they remained like this; it was as if time had simply stopped. But he never pulled away, never told her to stop. He just let her cry, gave her however long she needed.

He was warm compared to her, not cold and drenched like her own clothing, his chest rising and falling in a steady, comforting rhythm on which she tried to focus . It helped. Eventually, AC quietened down, a few last tear running silently down her cheeks.

It was so good to know that there was someone, that she wasn't alone.

She didn't wish to leave the warm embrace she found herself in, but knew that she had to. Additionally, she didn't want to drag him into this; he was a neutrophil, surely he had more important things to do and she didn't wish to bother him. These things happen all the time, she had to deal with it... somehow. "I… I have to go, " AC quietly mumbled, but given that the hand on her back stopped moving, he heard her. " My job… the CO2. "

The embrace loosened and her beret was rearranged, back to how it should be. "And I'm going with you."

...

U-4989 truly didn't leave her side. He accompanied her all the way back to the lungs, helping her finish the CO2-delivery, even shielding her in the heart from all the other red blood cells. In the packed chamber he stood right behind her , arms like a ring around her to give the erythrocyte space, preventing others from bumping into her as best as he could. At some point along the way, he also talked with someone over his transceiver, but AC didn't register what was being said.

After the CO2 had been dealt with, he took her to the area just outside the lungs, right next to all the little shops and booths, insisting she took a break. Frankly she didn't have the spirit to object. She felt both hollow and heavy at the same time.

They sat down on a lawn in the shadow of a tree, as far away from the main road as possible. Only a bit later U-1146 suddenly showed up, offering her his condolences, to which she merely managed to mouth a near silent thank you. He handed them both a cup of fresh tea each, before turning to his friend. She barely heard him promise U-4989 to take over his patrol before departing again.

AC didn't know how long they sat there silently side by side. Occasionally she would take a sip from her tea, feeling it warm her and with time her body began to feel less heavy, despite the images in her mind. At some point U-4989 gently placed a hand on her arm, his thumb brushing lightly across her membrane. The knot in her chest seemed to loosen a bit at that and she vaguely noticed her body moving a little closer to him on its own accord, until they literally were shoulder to shoulder . Truthfully right now she just didn't want to be alone; she needed to feel that she wasn't. And he didn't object, at least he didn't move away.

However, she couldn't help but feel just a little uncomfortable. "I'm sorry," AC mumbled guiltily after a while, clenching her fists, the teacup now empty beside her on the lawn. "I dragged you into this. You don't have to do this. " Surely he had duties, none of which could possibly include her. Not to mention that it had suddenly dawned on her how awkward this was. A leucocyte comforting an erythrocyte? Sure he'd tried to make her feel better before, but this went further than any of their previous interactions.

Yet he didn't seem to have any such reservations and gently grasped one of her fists, which were resting on her legs, almost enveloping it entirely. "Hey, I'm here now. I'm not leaving you alone like this, " the fluffy haired neutrophil declared softly, greatly easing her guilt. " He was a close friend, wasn't he? "

She nodded. "We grew up together." Her throat tightened and she snivelled. "He was like my big brother and now…" The tears threatened to return any moment now, she could feel them gathering.

But then his hand let go of hers again, his arm instead wrapping itself around her back and he pulled her against his chest once more. AC could feel his head resting ever so lightly on her head, cushioned by her beret. "I know."

"Huh?" His statement briefly confused her.

4989 hesitated for a moment, before he started to explain. "We're neutrophils. Daily some of us die to protect this body. " She felt his body tense up. " Some of them friends."

"Oh…"Of course he was no stranger to loss; he was one of the leucocytes, and their job was to fight. Naturally that couldn't always end well.

He continued. "I know we're supposed to get used to it, after all it is in part our purpose, but frankly I never really could. I guess I should be glad that my closest friends, those I grew up with together are still alive, even if it was close several times. "

"Bacteria?"

"Mostly; getting injured fighting them is a bit of an occupational hazard, and 1146 especially has this knack for playing hero. More than once I thought him dead and several times he really was at death's door. " His voice sounded a little shaky; he really cared for his friends.

Gently she squeezed the hand on her arm. "That close?" she asked softly.

"Too close." 4989 seemed to gulp. "Sorry; I'm trying to make you feel better and here I am making a mess of things, " he groaned guiltily.

"No, it's fine," AC assured him; while not per se comforting, somehow it did make everything else he was doing and saying feel even more sincere. She was so glad he was here. She was so glad he understood.

"It almost happened to me once too, you know," he said low-voiced. "Getting dragged from the face of this world."

The thought made her flinch. "During a fight?"

"Sort of. There was an abrasion, and I forgot to turn on the L-selectin right away. The draft would have pulled me out, if it hadn't been for a pipe I somehow managed to grab and hold on to. "

"Did the others save you?" He was still here after all. Thankfully.

He shifted his body a little; was the memory making him uncomfortable? And yet he still shared it. "Well, the platelets closed the wound, but I just kept clinging to that pipe; hanging over that dark abyss was terrifying, " 4989 confided and paused. " And then I got to spend three days as part of the blood clot; what better than a healthy dose of claustrophobia after a near death experience. "

AC knew that last part had been a joke, but it didn't change the fact that he had nonetheless been afraid of dying back then, the same way she almost had today. "Difficult to imagine a leucocyte fearing anything." She told him; they, 4989 in particular, turned out to be so much different from what she used to imagine.

"Hey, I tooam only a cell after all." His voice turned to a conspiratorial whisper and she could just imagine him winking. "But don't tell anyone, alright?"

A small smile flashed over her lips. "Your secret is safe with me," AC assured him.

"Much appreciated."

There was a pause, just enough time for her mind to wander back to the splinter. "I wish I could have saved him," AC confessed quietly.

Thankfully he pulled her just a little closer. "I know. Sometimes you just wish you could do more. Anything. "

"Yes, but..." She just barely managed to stifle a sob. "It was my fault."

"What?"

"There was that cell, he was trapped in the ruins. I wanted to help and FP followed me. " The haemoglobin twisted painfully inside her chest. " If I hadn't gone... "

Suddenly she was moved and before she knew it, they were eye to eye with each other, one of his hands framing her face. "It was not your fault." He sounded so serious, decisive. "You only did what you thought was right, and your friend chose to go with you, you didn't make him. And neither of you could have guessed what would happen. You tried to save him. You did NOT abandon him. " Her vision went blurry, and he pulled her back against his chest, this time embracing her with both arms, keeping her together. His head rested once more on her beret, while hers rested just beneath his chin, her fingers almost clawing into his uniform. "It was not your fault."

He had no idea how much it meant to her to hear him say that.

For a few minutes she just silently cried as he held her, as she tried to come to terms with her guilt, repeating 4989's words in her head. After a while she tried to look up to him, without really moving her head, her voice but a whisper. "How do you deal with things like this? Losing someone? "

He hesitated to answer. "I'm not sure," the neutrophil admitted. "Cherish my friends, I guess; they've always been there for me when I was struggling. I was never alone, and they helped me through it. " A moment of hesitation. " Red Blood Cell? "

"Yeah?"

AC felt him take a deep breath. "I… I'm glad you're still alive and though I didn't know FP, I'm sure he too would be glad to know that you've survived. " The erythrocyte bit her lower lip, a fresh tear in the corners of her eyes , but despite the residual feeling of guilt concerning her friend , deep inside she knew he was right about FP. " It was not your fault. " She wanted to cry again, but he gently squeezed her. " And I'm certain your friends are glad you're alive as well; they are still there for you. You're not alone either. "

Yes, she wasn't alone, CT and AD were still there. Right now however, it was 4989, who was here for her and grateful AC nestled just a little closer, closing her eyes, seeking the solace he so readily gave, appreciating his company. His own head, still gently resting on her beret, moved a little to accommodate her new position and they remained quiet for the time being. But their little talk had helped a lot. AC felt a little lighter; even breathing seemed easier.

The comforting moment didn't last, however. Eventually, she felt him lift his head, his embrace loosening. "Um… your friends are here. " 4989 sounded so deeply apologetic. " I don't want to freak them out, so… " And squeezed her arm carefully before letting go.

It took her a moment to realise what he meant, sensing him vanish and she opened her eyes again. To her distress finding herself all alone AC turned around, but he was already gone , probably having migrated through the thin gap she spotted between the two buildings behind her and the tree . The knot in her chest tightened again.

But he was right. When she looked the other way, the erythrocyte saw that AD 5022 and CT 2980 were walking down the road coming from the lungs , each with a box O2 in hands . She had to tell them. They had to know. Her chest hurt a little again.

Taking a deep breath AC got back to her feet. She walked to them, her legs still feeling stiff, but she neither waved nor shouted. Thankfully they spotted her anyway and came to join AC at the side of the road. How should she tell them? She wished 4989 was still here; she felt so vulnerable.

Her friends seemed in good spirits, however their smiles vanished once they got a look at AC 4293. CT carefully placed a hand on her shoulder, studying her with a troubled look. "AC? Hey, are you alright? "

And she told them. Her voice was low and shaky, she broke off more than once, but she managed to tell them. AD paled as he listened, he looked devastated, while CT was soon at the verge of breaking into tears. Once AC had finished , she then wrapped her arms around the auburn haired erythrocyte tightly, who hugged her friend back, trying to give solace, while seeking it herself.

But AC herself didn't cry, she couldn't anymore, even as her friend started to sob. Her own eyes felt completely dry by now. Without saying a word AD then simply embraced the two.

Suddenly it was only the three of them.

...neither ever blamed her.

Days passed, and things stayed quiet for the most part.Business as usual. 4989 was frankly starting to feel a bit bored again, which to be fair was in part thanks to his current assignment. Acting as sentry at the right atrium of the heart, just were superior and inferior vena cava met, wasn't exactly an eventful occupation, but at least he wasn't alone.

"Not enjoying guard duty?" 2626 asked when he saw his friend stifle a yawn.

The fluffy haired neutrophil sighed. "You mean standing around, doing nothing?"

The other leucocyte merely shrugged. "Just enjoy the break, or would you rather swap with someone at the intestine?"

"Point taken." Constant fighting wasn't exactly what he was looking for either; some middle ground would be nice. Or a place where he could try out new weapons. Busy roads weren't exactly ideal, and he had a few ideas he wanted to try out. Still, just standing here was starting to make him edgy; he wanted to move. "How do you feel about tea, though?"

"Not a bad idea."

Thankfully there were a few stands and vendors around, even if not as many as in the pulmonary vein, providing an opportunity for erythrocytes to refresh themselves before entering the heart , something especially those coming from the inferior vena cava probably appreciated.

The two neutrophils kept to the side , not wishing to walk against the flow of cells headed into the atrium, though still scanning the area , given that they were nonetheless on duty . Somewhere along the way, something caught 4989's eye. "Hey; I think I see AC 4293. " Plaits weren't exactly common and in combination with that dark, auburn shade, he could only think of one erythrocyte.

"Have you seen her since the splinter?" All his friends knew about what had happened to her; 4989 had informed them while he'd accompanied the red blood cell back to the lungs, to let them know why he'd changed his patrol route.

"No," the fluffy haired neutrophil replied. "Mind if we…?"

"Of course not."

He was still worried about AC 4293. Losing her friend, watching it happen and nearly having died herself again had clearly been traumatic. Even to him the thought that she had only barely escaped death made his lysosome twist. And the way she 'd talked about it, how she had clutched her friend 's glove had even made 4989 concerned she could develop some sort of survivor guilt, something he himself wasn't entirely unfamiliar with, or at least the feeling that you could have done more . The idea that she had felt responsible too...

"… I'm sure he too would be glad to know that you survived. "

Had what he said help? More often he , someone who was usually considered rather emotional by his fellow neutrophils, had received comforting words or gestures rather than given them and he certainly had never tried to console an erythrocyte before. Well, AE 3803, who had quite a knack for getting herself into trouble, a little once when 1146 had been critically injured, but they had known he would recover so it hadn't exactly been the same thing. How was it that it always seemed like the nicest people had to go through the worst experiences?

Fortunately, the erythrocyte was walking near the side of the road as well, making drawing her attention an easy enough task. "AC 4293," he greeted her, putting on a warm smile, waving to make sure she saw them. "Hi."

She spotted them and much to 4989's joy actually made her way over to them , careful not to accidently hit another cell with the box she was carrying in her arms . "U-4989, U-2626; good to see you. " Her smile, while genuine, still seemed a little weak, but nonetheless the fluffy haired neutrophil was glad to see it. She really appeared to be doing better.

Meanwhile, 2626 replied. "You too, miss. My condolences for what happened, " he added sympathetically.

Sadness snuck into her smile, turning it brittle. "Thank you."

"Just wanted to ask how you were holding up," 4989 piped up gingerly, still feeling concerned.

"It's been difficult," AC 4293 admitted, lowering her gaze, hugging her box a little tighter. "A part of me still kinda expects to see him again, crossing paths as usual, going on deliveries together." Now her eyes met his and her little smile returned, but this time he also saw gratitude in her expression. "Thank you… for having stayed with me. For what you've said. "

Guiltily the fluffy haired neutrophil tugged a little at his cap, as if trying to hide his face in the shadow of the peak. "I'm sorry I left so abruptly that day, I just…"

Quickly she shook her head. "Don't worry, I understand. Truthfully I don't think I could have dealt with my friends going ballistic as well after everything that had happened. "

"Yeah; after meeting one of your friends, I kinda figured they wouldn't exactly approve of me being around. " It still frustrated him that leaving had been necessary at all. Would it always be like that? The original plan had been to get erythrocytes in general to be less afraid, not just AC 4293. He would think about that later. First things first and sheepishly he rubbed the back of his head. "I have to admit, I wasn't sure how much help I was in the first place anyway."

The erythrocyte' looked at him surprised. "What? No, of course you helped, I was such a mess. " Her cheeks flushed, her gaze and voice lowering. " That you even took the time to keep me company; really, I'm grateful. Frankly I 'm not sure what I would have done , or how I would have made it back all the way to the lungs , if you hadn't been there. "

4989 felt mitochondria jump with elation. "Well, then I'm glad I could help a little." A noise suddenly reminded him that they weren't alone and he turned to his friend, still standing beside him. "What are you chuckling about?"

2626 grinned. "You, 4989; you have always been the heart of our little group. "

"Oh, yeah?"

The other neutrophil nodded. "Yes; 1146 is the serious one and 2048 the most level-headed. "

4989 looked at him questioningly. "And what does that make you?"

"The handsome one, obviously." His friend said straight-faced, in a very matter-of-fact manner.

"Those bangs cover half your face." The fluffy haired neutrophil promptly pointed out.

"Now imagine if they didn't."

4989 furrowed his brow. "Then how come 1146 is the one with a girlfriend?"

2626 merely shrugged. "Lack of effort on my part really."

"U-1146 has a girlfriend?" AC 4293 piped up surprised.

"Huh?" Oh right, she didn't know. Well, no point denying it now and frankly he didn't mind the switch to a more light-hearted subject. Perhaps it would be good for her too. "Yeah, you've actually met her once. It's AE 3803. "

Her eyes widened, evidently remembering the other erythrocyte. "That's why he was so troubled, when I mentioned she had a parasite."

" Well , they weren't together back then , just friends, but they got together after that incident ," the fluffy haired neutrophil explained.

"With a bit of help from us," his friend added.

She frowned a bit suspiciously. "How did you help?"

"They've always run across each other regularly, but for them to actually admit their feelings and take that next step, it needed the right location." He was still proud that his idea had worked so well. "And so we got them to the retina with a view into the eye."

There was a sparkle in her own bronze eyes. "Oh…"

"You've been there as well?" 2626 asked curiously.

The erythrocyte nodded. "Only once, but it was absolutely gorgeous. I ended up lingering there way too long, but my client was thankfully very understanding; apparently that happens a lot. " A bit embarrassed her cheeks flushed a little again, but like before she quickly recovered. " And sending them there worked? "

4989 nodded. "Well, they finally confessed their feelings."

"Plus we stuck around and made sure no antigens distracted them," the other neutrophil pointed out, before he sighed. "Would have been a shame if in the crucial moment 1146's receptor had gone off."

"Yeah, that could have ruined the mood," AC admitted.

The fluffy haired neutrophil chuckled amused. "A little."

2626 nodded in agreement and nudged him with his elbow. "Well, I'm gonna go get that tea now." He bowed his head to AC 4293, holding the peak of his cap between two fingers . "Good day, miss."

"Bye."

"Right behind you," 4989 told his friend as he went ahead, before turning to the erythrocyte again. "Sorry; technically we're on guard duty around here," he apologized; at least he now knew that she was recovering. That certainly was a weight of his mind.

"It's fine." She lifted the CO2 box in her arms a little for emphasis. "I got a delivery to make myself."

"Alright; well… see you around, AC 4293. " And waved goodbye. He was about to turn away.

"4989?"

And stopped. "Huh?"

She was smiling, for real this time. It really did look good on her. "Just 'AC' is fine."

Chapter Text

Author’s Note:

It’s been a long, long time, not gonna lie. Bad news is, I won’t be adding any more drawings to the story; between work and so many other projects I just can’t find the time and at this point the motivation. But I will publish the remaining chapters, if possible within the next week or so, finally completing the story.

Best wishes, CorvusAlbus/MiraAvis

Sacrifice

It was such a nice day. 4989 was humming a merry tune as he walked from the torso down towards the abdominal region of the body, finishing the tea he'd gotten earlier. He was supposed to meet up with 1146, as they were scheduled to go on patrol through the gut. It was one of the most dangerous places in the body, which was why even neutrophils tried to team-up when they were on duty there. The strange thing about the human body was that it was home to more bacteria than actual human cells, and most of those bacteria happened to be located in the intestine. Thankfully the majority was not only good but also vital for the body, helping it to absorb nutrients and water, as well as keeping their harmful cousins at bay.

Still, there were always those actively seeking to invade the body or those simply waiting for the right opportunity. In essence, there was no such thing as a quiet patrol through that particular region.

Eventually 4989 reached the agreed upon meeting point, finding himself on a little bridge across another street. The fluffy haired neutrophil looked around, until he spotted something that immediately made him smile. U-1146 had already arrived and not alone. By his side was AE 3803, a hand on her delivery cart, brightly smiling at her neutrophil boyfriend.

They stood together on the road below, keeping to the side as to not disturb the blood flow, probably saying goodbye as the two shared a kiss before parting. As she turned, AE spotted 4989 on the bridge and waved, the neutrophil happily returning the gesture, before she re-joined the crowd of erythrocytes, soon disappearing between the other red-clad cells.

1146 meanwhile walked up the steps to join him, a content smile on his lips. It was good to see him like this. Sure 1146 had always been satisfied with his role, even enjoyed parts of his job, he certainly cared for his friends and acted like a big brother around the platelets, but he had also always been one to worry quickly, to occasionally overthink. More than once 4989 had worried about his wellbeing, not just his health, but his mental state as well. Constant battles for the very survival of this world and perhaps more than just the occasional near-death experience; that could wear anyone out.

However things had changed since AE 3803 had come into his life, especially since they had discovered their true feelings for each other. At least those who knew him had noticed.

4989 was certain that he'd never seen his friend smile so much; he seemed more relaxed when things were calm, yet fiercer in battle at the same time, as if he was fighting with stronger conviction or renewed purpose. All things considered, regardless of what cells like Memory-T thought, he was doing better than ever. And 4989 couldn't be happier for them both.

"And what are you grinning about?" 1146 questioned when he joined him on the bridge.

4989 winked. "You two just look so adorable together. Would you like me to go alone?" He asked cheerfully, nodding toward the street AE had taken. "You could join her on her delivery."

His friend however merely shook his head. "Thanks, but we've agreed that we wouldn't compromise our duties, because of our relationship." His smile returned and the two began to walk down the road to head deeper into the digestive tract. "Besides, we'll meet again later."

"Alright; just wanted to offer it. I still owe you for taking my patrol, when I helped out AC 4293."

1146 lifted a hand, shaking his head. "Don't mention it. How is she doing, by the way?"

"Much better." He told him excitedly. "I've seen her a couple of times since and she seemed alright. She misses her older brother of course, but she's coping quite well from what I can tell." And she was smiling more again; he couldn't express how glad that made him.

His friend however furrowed his brow questioningly. "Sounds like you didn't talk much." He noted.

4989 smile faltered a little. "Not as often as I would like; her friends are not fond of leucocytes of any kind, so when they are around…." He explained disappointedly. Still, he had managed to talk with her a few times though, taking AE 3803 advice and bringing her tea and glucose whenever he spotted her on her own.

The first two times she'd been a bit confused by the gesture, but had never declined and thank him nonetheless. Their chats however were always brief, little more than catching up with each other before returning to their respective duties. It was partially his fault; 4989 simply wasn't sure how to talk with her. Even telling her about his day might gross her out; she just wasn't used to it like AE. Besides, he just couldn't help but notice that she appeared nervous, so it just seemed like a good idea to not aggravate that tension by sticking around.

What even were they? Strangers certainly not, so acquaintances? He wanted to be friends, but that term didn't seem quite right…yet. He had to do something about that.

"Wasn't it your original plan to remedy that that particular issue? Do something about that general fear towards us?" 1146 inquired, tilting his head a bit.

4989 sighed, rubbing his neck, feeling a bit put on the spot. "I know." He lamented. "But so far I've only managed to approach AC; you know, trying to help her cope with her scar and the death of her friend."

"I'm afraid that won't help much with the overall erythrocyte population."

"You're right, but I'm really not sure how to go about that." One red blood cell at a time was of course nonsense, but what was he supposed to do? Give out flyers? No, there had to be a more practical way. "Who knows; maybe by getting to know AC I can figure something out." If she could overcome her fear, she might have an idea how others could as well, though he shouldn't count on that.

For a moment his friend looked at him thoughtfully. "So, you really want to be friends with her."

"I like her." 4989 admitted, smiling again, his cheeks feeling warm. "She's nice and even quite fun, when she isn't intimidated; shame you weren't there at the wash station."

"The others told me a bit." 1146 mentioned, the corners of his mouth lifting a little. "And you wouldn't consider yourselves friends already?"

"Not really." He could hear the disappointment in his own voice and he looked at his chalk white clothes. "She's kinda nervous around me; I fear it's still difficult to see past the uniform."

The other leucocyte frowned again, but this time in a disbelieving manner. "You're sure? I've seen you talk to her the other day and you sounded just as nervous as her."

That was kinda true. "Just because I'm worried about saying the wrong thing." 4989 told him, even though he was a little embarrassed to admit it.

"And how do you know it's not the same with her?" 1146 pointed out with an encouraging smile and placed a hand on his friend's shoulder. "Perhaps she doesn't care about the uniform anymore, but just like you doesn't quite know what to say. All things considered, she's even newer to this than you."

4989 stared blankly at him. "Oh…" That he hadn't considered. He'd already made some experiences with AE 3803, but AC had probably never spent extensive time with a cell of another type.

"Besides, didn't you just console her after she lost her friend? You really think she would have let you hug her and keep her company all day if she didn't at least trust you? If she wasn't comfortable? And from what 2626 told me, she was very grateful for that." He shrugged, pulling his hand back again. "Maybe it's just me, but you seem to be friends in all but name."

"You think?" The fluffy haired neutrophil asked hopefully. All he had noticed was her apparent un-comfortableness and made a point not to outstay his welcome. Had he interpreted this all wrong? Maybe he should have thought about this a bit more.

"You might want to join her on a delivery." 1146 suggested, picking up on his friend's improved mood. "Your little five-minutes chats only get you so far." There was no denying that and it was something he'd like to change.

Yeah, now that he thought about it, maybe it was time to do just that. 4989 couldn't help but grin confidently. "Well, guess I have plans for later then." If she was alright with that. He just didn't have to stutter like during their initial encounters…. or cry; seriously he'd almost shed some tears when consoling her. Good thing that with his head on top of hers she hadn't seen it.

The other neutrophil chuckled at his enthusiasm, but 4989 didn't mind. "Tell us how it went. AE 3803 has been curious…" But he was suddenly interrupted by a slightly distorted voice.

"U-1146, U-4989; come in."

His friend reached for his transceiver. "U-1146 speaking."

"U-2048 here. You and U-4989 are on patrol in the intestine?" 4989 good mood dampened immediately. That didn't bode well; not that he had expected this patrol to be peaceful anyway.

"Just started our round." 1146 confirmed, his expression too looking much more serious than it had only moments ago.

"Good. We have an invasion at the colon and not the typical kind. We could really use any help we can get."

4989 took his own transceiver and joined in. "Do you know what germs we're dealing with?"

"Not yet, but I'd say some kind of E. coli. In any case, we have a bunch of destroyed epithelium cells. Even an M-Cells has been hit; they seem to have been poisoned." That really didn't bode well at all.

"We're on our way." 1146 merely replied gravely.

"Guess I'll be taking a shower before joining AC." The fluffy haired neutrophil noted half-jokingly, trying to lift the mood, if only for a second.

For a moment his friend's lips indeed curved to a faint smile. "I'm sure she'd appreciate it." Before he turned back to the transceiver. "2048; where do you need us?"

AC 4293 stretched her arms, feeling quite relaxed and rested. It had been an easy day so far and after enjoying a break at the colon, she had just started to head back to the small intestine, where she was supposed to pick up her next nutrient delivery. Maybe it would get her someplace interesting like the head, which had always been one of her favourite areas.

Perhaps she would cross paths with 4989 again too. She'd seen him almost daily since the splinter, often bringing her refreshments, asking how she was faring. Frankly she very much enjoyed his company. He was always so sweet and kind to her, not to mention that it was difficult not to smile when talking to him, thanks to his cheerful disposition. It was infectious; ironic really.

So it was a shame that she never quite knew what to say, something AC could kick herself for, in part because she wasn't quite sure what they were. They certainly weren't strangers anymore, beyond that she just wasn't sure.

It didn't help that he always left so quickly again. He made sure she was alright and left almost as quickly as he'd appeared.

A part of her had started to wonder, if he only sought her out because of pity. Of course she remembered his wish to not be feared by every none-immune cell, but that didn't mean he wanted anything further, that he wanted to be friends; perhaps that particular intention was just something she had wrongly interpreted from what he'd told her at the ear.

Maybe he was just being friendly, which strangely enough bothered her, made her nervous. What if he no longer sought her out once he noticed that she was fine and no longer struggling with the death of her friend? After all, she was one of millions of erythrocytes and so far he'd mostly seen her timid, vulnerable side. Way to make an impression.

Frustrated AC ran a hand over her face. Ugh, what was she thinking? He must have spent hours by her side, holding her, consoling her, when she had been at her lowest. He'd even opened up to her about his own, similar experiences. Certainly no one would do that just out of pity, right?

The auburn haired erythrocyte sighted. She really needed to stop with this self-loathing; it was a horrible new habit she'd picked up since…since FP's death.

Still, the issue remained that their recent conversations seemed to end before they really begun. If there was to be a chance for them to become friends that needed to change; surely she could do something about that.

If she met him during her delivery, perhaps she could invite him to join her, find out what he'd been up to. Strangely enough he never really spoke about his job, only his friends. Did he fear that she might get freaked out? Sure, killing and eating bacteria was undeniably a bit disgusting, but it had to make for more interesting stories than her deliveries. Besides, she was genuinely curious at this point. If these past few weeks had proven anything it was that she knew way too little about white blood cells.

AC thought back to the ear, the tussle at the wash station, the tea afterwards with him and his friends. It could work. Yeah, she could do this; she just needed to give it a shot.

The young erythrocyte reached the ascending colon, however almost as soon as she did all hell broke loose. A handful of erythrocytes came running from one of the smaller vessels to the main road she was on, screaming, shouting, causing a panic.

"Germs!"

"Run!"

Oh, come on.

When she'd been an erythroblast a neutrophil had taught her and her classmates how to escape. Just run. Don't stand around, trying to look what's after you, just run away; the whereto and how-far took care of itself. But it was never quite that simple.

As soon as AC started running, another red blood cell lost control of his cart and it crashed against her foot. The pain shot up her leg, making her see white for a moment and hissing sharply AC stumbled to her knees. The other erythrocyte continued to run, eyes full of terror, fixed on something behind her. Oh no.

"An erythrocyte?" A deep voice hissed pleased. "How convenient; I'm feeling a little peckish."

She should ignore the pain and run. AC knew that, but despite being frozen in horror something made her glance over her shoulder nonetheless. Behind her approached four centipede-looking creatures of a metallic green-black colour, though their heads were more snake-like, long fangs emerging from their upper jaws and coated with a watery film.

"Leave something for us." Another in the back spoke, its pink eyes fixed hungrily at AC, sending shivers down her spine.

As the one closest to her opened its jaws wide, preparing to bite, AC knew that she couldn't escape, not with her injured foot. Still, somehow she managed to stumble forward in a desperate attempt to do something, regardless how futile. Any moment now. It was lready casting its shadow upon her.

"Don't you dare touch her!"

The bacterium halted in its attack, and turned around. AC too stopped and did the same, recognizing that voice. Could it be?

A neutrophil dashed towards the germs like a white thunderbolt. He jumped and threw something, not knives, as AC saw it expand and reveal a white net that fell upon three of the bacteria. Immediately they screeched in pain, struggling against the fine threads that seemed to stick to them like fibrin.

The fourth, still standing just behind AC snarled threateningly, head lowered, a pair of its centipede-legs raised defensively. The neutrophil dodged a swing by one of those pointy appendages, leaped and landed on the bacterium's back.

AC gasped, the paralysing fear all but melting away in an instance. It really was 4989. In one hand he was holding what looked like a spear, though at second glance she realized that he'd tied one of his knives to a pipe, but something else really caught her attention. His expression was one of pure bloodlust and rage, almost making him look like a completely different person.

He was baring his teeth, his eyes wide and filled with murderous intent, fixed on his enemy. She'd seen him finish off a germ once, but she'd actually never really seen him fight. It was intimidating. He rammed the spear into the bacterium's back, the blade cutting through the membrane until it was deeply imbedded. The beast hissed, whirled around and tried to bite him, but the neutrophil nimbly dodged the frantic attack, drew a second knife with his left hand and stabbed into the germ's head from below. It stilled, the large body trembling, and with another slash, 4989 opened its throat, making sure it died.

Finally the bacterium collapsed and the neutrophil jumped off, letting his knife slip back into its sheath, before pulling out his spear.

And he turned to her.

It was as if someone had flipped a switch; his eyes softened, the murderous glare exchanged with a caring expression of genuine concern as he scanned her, gingerly stepping closer. It was such a contrast to the sharp precise movements he'd displayed in battle.

He crouched down next to her, making sure his spear pointed away. "Are you alright? Did they hurt you?" The fluffy haired neutrophil reached out with his free hand, but didn't actually touch her, perhaps because he was covered in bacterial cytoplasm, some dropping from his fingers.

AC tried her best to ignore his bloodied appearance and shook her head. "No. They didn't even get the chance." She assured him, feeling guilty for having actually felt intimidated by him a few moments ago. No matter how he looked, it really was still him.

4989 breathed out relieved, his shoulders sagging down. "Thank goodness."

"What were those?" She glanced over to the corpses, the net having etched into their membranes, which was admittedly somewhat disturbing.

"Pathogenic E. coli, a particular nasty version that produces toxins." He looked at her troubled. "Among them haemolysin."

AC's eyes widened in horror. "They would have…?" Getting killed swiftly was one thing, getting melted alive however…her cytoplasm shivered at the thought, her haemoglobin twisting in her chest.

EHEC

The strains of Escherichia coli known as enterohemorrhagic E. coli are toxin producing bacteria that are always human-pathogenic. They destroy cells of the intestinal epithelium via verotoxin, leading to watery diarrhoea. This toxin can also destroy cells of the blood vessel endothelium, causing symptoms such as bloody diarrhoea and spasmodic abdominal pain. Furthermore it can also kill immune cells ingesting the bacteria, such as macrophages, while another toxin, haemolysin, destroys erythrocytes.

Antibiotics are not recommended as they can further stimulate the production and release of toxins. Instead symptoms are treated, such as keeping the patient hydrated to counter the diarrhoea.

The fluffy haired neutrophil seemed to notice her reaction and looked her over once again. "You sure you have nothing on you? Your clothes?"

Thankfully that was impossible. "No; one wanted to bite me, but then you showed up." She smiled, genuinely grateful. "Thank you."

4989 returned her smile, his cheeks gaining a faint pink hue. "Glad I was in time." He told her, visibly relaxing.

"By the way, what did you use?" AC asked and nodded at the net he'd tossed across three of the germs. "Did you steal some fibrin from the platelets?"

This seemed to puzzle him for a moment. "What? No, this is mine; a weapon exclusive to us neutrophils. It's called a 'neutrophil extracellular trap', or NET for short."

NET

Neutrophil extracellular traps (NETs) are meshes composed of chromatin and antimicrobial proteins, which bind pathogens such as bacteria or fungal cells, trapping and ideally killing them. They can also stimulated other immune cells and an inflammatory response. There are several activation pathways, like through contact with bacterial lipopolysaccharides (LPS) of gram-negative bacteria such as E. coli or interactions with platelets that have been activated by damage endothelium cells.

"We can use it to capture and kill several enemies at once, make sure they don't escape. We have to be cautious though, or we risk trapping the wrong cells, block roads or cause an unwanted overreaction by the rest of the immune system. You see, they are made from nuclei acids, and usually their release is something that really gets all alarm bells going, because it indicates damaged or destroyed body cells. Even though we're just doing our jobs that can cause more harm than good in the end, kinda like an allergic reaction. So we gotta be careful when to use our NETs."

That sounded really dangerous, no wonder she hadn't seen it before; neutrophils even used their throwing knives sparingly. Still. "I'm glad you used yours this time." She confessed; who knew how the fight would have turned out otherwise.

"I was worried I wouldn't be able to take them all out in time." 4989 explained and once again he looked concerned. "You better stay clear of this place; frankly these shouldn't have gotten into the bloodstream in the first place, but I can't promise others won't make it as well."

"How did these do it?"

He pointed to somewhere behind him. "Collateral damage; the nearby blood vessel took too much and was torn open. Right now we're trying to contain the invading E. coli as best we can. I gotta go back help the others quell this invasion."

Now she worried. How many of these things were there? How long would he have to fight? Would they get reinforcements? "Stay safe, alright?" Was all AC however managed to say as he stood, clenching her fist.

He smiled one more time, his big eyes lighting up for a moment, before running off. "You too."

His mitochondria were pounding in 4989's chest as he ran. She was alright, she was safe now, but that had been far too close. He dreaded to think what would have happened if he'd arrived but a few seconds later. If that platelet hadn't shown him which way the bacteria had gone…the neutrophil shook his head and gripped his spear tighter. He couldn't think about what might have happened, what mattered now was preventing the germs and their toxins from spreading.

It didn't take him long to reach the battlefield again and not much had changed since he'd left. Neutrophils and macrophages alike were holding the line against the invaders, plenty of which were now lying scattered across the field of debris that had once been home to so many cells. As chaotic as everything appeared, it seemed as if the immune cells were at least managing to contain the bacteria for now.

He readjusted the grip on his weapon and leaped straight back into fight. "Die germ!" The E. coli screamed as he rammed the spear straight through its head, blade re-emerging through its mouth.

U-2048 greeted him with a grim smile, though keeping his eyes on the next wave of enemies approaching them. "Welcome back."

"Missed me?" The fluffy haired neutrophil asked brightly, wiping cytoplasm from his chin with the back of his hand. His friends were still where he'd left them and thankfully none seemed seriously injured, nothing appeared to go beyond scratches, bruises and torn uniforms.

"We started to worry." 2626 replied, pulling his blade from the body of another dead E. coli, strands of his bangs sticking together thanks to cytoplasm.

"You got the escapees?" 1146 asked and launched a batch of throwing knifes as a nearby germ that was about to attack 2048, making it flinch and stumble, allowing their friend to cut it down.

"All four, but seems like there are plenty left here." This was particularly troubling, given that this bacterial strain could do serious harm even in small numbers.

HUS

Haemolytic-uremic syndrome; a usually post-infectious, possibly lethal disorder, most commonly associated with bacterial toxins, such as the EHEC verotoxin. These cause damage to the endothelium cells, including those in the kidney's glomeruli, leading to apoptosis and an activation of coagulation factors as well as thrombocytes (platelets), creating clots in the small blood vessels. This results in haemolysis and eventually haemolytic anaemia, thrombocytopenia (low number of platelets in blood), kidney failure as well as a multitude of other symptoms.

"Yeah and more are getting in through the damaged epithelium." 2048 confirmed. "If we don't get this under control soon they and their toxins will spread."

"Any word on the lymphocytes?"

"Not yet." 2626 replied somewhat disappointedly and gave him what was probably supposed to be a meaningful look. "You know how it is."

The fluffy haired neutrophil couldn't help but groan. "This antigen representation takes way too long." Not for the first time.

Before one of the others could respond their transceivers demanded their attention. "Neutrophils!" 4989 new this voice; it belonged to one of their oldest comrades still patrolling the body. While neutrophils didn't use ranks like lymphocytes, seniority and experience were still respected. "Set up a perimeter! Push the invaders to the centre of the battlefield at all cost! Senior members of the division are to gather there now!"

The four childhood friends exchanged glances. "Do you think they want to…?" 2048 asked them, though they all knew the answer.

"These germs could kill the body, even if they don't make it any further than this." 1146 reminded them gravely. "I think they are going to do it."

4989 gulped, feeling his insides twist. "Can't we really just wait for the lymphocytes?" Maybe if they arrived in time, the tide could still be turned, negating the need for more drastic measures.

"With even macrophages getting poisoned and more of their toxin leaking into the blood system?" 2626 questioned, though the fluffy haired neutrophil saw him clutch his weapon tightly, the tension of his body revealing his displeasure at what was about to be done.

"They are not going to risk that." 2048 confirmed sombrely.

1146 took a deep breath and marched forth. "We have our orders. Let's make sure they're not doing this in vain."

The other three acknowledged as one. "Roger."

This was stupid. AC knew she shouldn't be here, but nonetheless she had not headed to the small intestine, but instead followed 4989. With her foot still hurting she was significantly slower than usual, but had eventually reached the outskirts of the battlefield. It was admittedly hard to miss.

Two of the buildings making up the blood vessel's inner wall, the endothelium, had been quite damaged, and the small gap between them usually only migrating cells like neutrophils could fit through, was now a wide hole. If there was another one in the intestinal wall, through which she assumed the invaders must have gotten in, erythrocytes could get swept out into the colon!

Carefully AC stepped closer; despite every instinct warning her, she just had to know or she would not find peace today, or be able to focus on her work properly. Standing at the hole, one hand against a wall, she suddenly felt a little draft, but nothing dangerous. Maybe it wasn't as bad as she'd feared.

The auburn haired erythrocyte took her first actual look at the battlefield and knew she was wrong. Where there had once been the homes and work places of muscle and conjunctive tissue cells, was now a field of debris littered with the corpses of bacteria. On the ground their bright red cytoplasm mixed with a watery liquid, likely the toxins, which actually seemed to erode whatever they touched. No wonder the intestinal epithelium and the blood vessels had taken damage.

Perhaps scarier however was the sight of a nearby macrophage, clearly wounded, pale as a neutrophil. Another of her kin had helped her to the edge of the battlefield, not far from where AC stood. Had she too been poisoned? Was that possible?

Watching the female immune cell sit down, leaning on her oversized cleaver, the young erythrocyte grasped her plait, squeezing it nervously. If even those cells could be harmed, what about neutrophils?

Turning her attention back to the fighting, she watched as the leucocytes began to encircle the invaders, herding them to an area near their point of entry. But that was the thing, they were driving them a certain direction, not killing them. How did they plan to dispose of so many enemies? The place was crawling with the green-black bacteria, fighting back with long fangs and sharp-edged, pointy legs.

As she watched AC 4293 couldn't help but notice that there were hardly any lymphocytes. She spotted a few B-Cells, probably providing assistance with unspecific antibodies, but it seemed as if the majority of the adaptive immune system had not yet joined the fray. Surely they had to know about this by now.

The next thing the erythrocyte observed was that a small group of neutrophils were gathering amidst the herded together E. coli. It seemed like suicide to her. Transfixed AC watched the group of granulocytes then split up, dispersing in the crowd of bacteria without actually fighting them. For some puzzling reason they only seemed to be dodging their attacks. Just what were they planning?

As if on command the neutrophils at the centre then suddenly grabbed or attacked the germs they were among, but not with their blades. They used NETs. She recognized the white mesh, however those weren't as small as the one 4989 had used; these were massive, large enough to cover and bind most of the invading army, two-thirds at least. It almost looked like a blood clot in the end, though unlike red blood cells the germs were struggling against the sticky threads. Even from far away AC could hear them scream, as the mesh cut into them.

Then something hit AC. What about the neutrophils? They were trapped along with the bacteria!

In the meantime, the few remaining germs panicked, caught between the NETs and the ring of other neutrophils and macrophages surrounding them, suddenly finding themselves outnumbered for the first time in this battle. Just like that the tide had turned.

The leucocytes advanced, cutting down their enemies with renewed vigour. But that was not all.

"Move!" A deep male voice bellowed behind her. "Out of the way!"

Startled AC instinctively leaped aside, pressing herself against the nearest wall, just in time. A battalion of black-clad T-Cells ran past her, with them a few more B Cells, probably now equipped with specialized antibodies.

Battle cries were shouted and the lymphocytes finally joined the battle. Despite their intimidating presence, AC felt reassured by their arrival and sighed relieved, letting go of her plait again. Now the E. coli surely stood no chance. This would be over any minute now.

Remaining at the broken endothelium, the erythrocyte watched as the last of the germs were snuffed out by the united forces of immune cells, some of them crying out in fear or pain before being silenced. Though their end was brutal, AC felt no pity, only gladness, even if it was muted with lingering concern, a few of her fingers running over her braided bracelet.

And then it was silent.

To her surprise there were no cheers after the last E. coli were slain. The battle simply seemed to end. Slowly the leucocytes began to tend to their wounded, carrying them off the battlefield, while the macrophages started to collect the dead bacteria, probably to process them; she'd seen their giant pots.

AC hesitated, until she finally left her spot at the wall. She knew she wasn't supposed to leave the blood vessels, but admittedly she didn't care right now and so stepped into the destroyed tissue. Most immune cells simply ignored her and continued their work, others seemed confused by her presence, yet didn't stop her either as she began to search the area.

Eventually more neutrophils arrived at the scene, apparently relieving those who had fought here, which was probably for the best. They all looked so exhausted, all wounded to varying degrees, which did nothing to ease the erythrocyte's mind, her fingers once more feeling over the bracelet.

Slowly the relieved neutrophils left and AC noticed that they seemed downcast, hardly speaking to on another. The implication made her shiver; how many had they lost today?

As she looked around, AC actually spotted U-1146 among those leaving. It was good to finally see a familiar face and she was glad that he too had survived this battle. As the neutrophil walked towards the blood vessel he was suddenly approached by a red-headed erythrocyte, who was ignoring the rules same as AC and apparently offered him a tissue. This had to be AE 3803, his girlfriend; AC remembered that distinct hair curl she could even see from a distance. As AE studied 1146 with a worried gaze, he spoke to her with a reassuring smile, despite looking tired from the long battle.

AC 4293 turned away to continue her own search. He had to be around here somewhere too…

"AC?" At hearing that surprised voice, her haemoglobin leaped into her throat, warmth blossoming in her chest. He'd survived. "What are you doing here?"

She turned around and gasped, as a completely bloodied 4989 joined her on the large chunk of debris she'd used as vantage point. "I…I just had to know." The erythrocyte admitted timidly, a hand clutching her shirt just above her chest. "Are you alright?"

Aside from the cytoplasm, his clothes were torn, but thankfully he didn't seem seriously injured, at least to her inexperienced eyes. For a moment he stared at her, evidently flabbergasted, but then a smile spread across his lips. "…Yeah, yeah; just bruised, nothing serious." He assured her. "I don't think this is any my cytoplasm really. Well, not much anyway…"

AC breathed out relieved, but it was followed by an awkward silence. She hadn't exactly planned this far ahead and he too seemed a bit lost. As she wondered what to say, her eyes returned to the sight near the intestinal wall. "4989? Those neutrophils, what...what did they do? I saw NETs, but there was so much. I thought they were just those little meshes."

He stiffened, his smile faltering immediately. "Wh..what I did was vital NETosis, I just used a bit." The fluffy haired neutrophil explained and patted one of the pockets on his uniform. Then he hesitated for a moment, only continuing reluctantly. "But we can also use more drastic measures as well."

A part of her dreaded to press on, but she wanted to know. "What measures?"

Saddened he looked back to the battlefield and took a deep breath. "NETs are made from our DNA, nuclear or mitochondrial, so if we need to deploy a lot, if there is no other way, we…we can release everything we have."

"Release everything…how?" A part of her could already guess.

A little hesitantly 4989 showed her his bloodied knife. "We either open up our own membrane or allow a pathogen to wound us, often we'll grapple one of our targets too, using ourselves and our NET to trap and kill the germs. It's called suicidal NETosis."

Suicidal NETosis

There are two versions of NETosis. During vital NETosis the neutrophil quickly releases a vesicle containing the mesh, leaving their membrane intact, allowing the leucocyte to continue phagocytising microbes.

During suicidal NETosis however the neutrophil's membrane ruptures, realising a large amount of chromatin-mesh, killing the immune cell. This can take hours, compared to vital NETosis, due to the extensive intracellular NET formation.

Both are activated via different pathways.

AC's eyes widened. "They sacraficed themselves." She breathed horrified.

4989 gluped and nodded. "Yes." Quickly he put the blade away, trying to muster a brave smile, but struggled, making it look brittle, even sorrowful instead. His eyes shimmered. "We're neutrophils; eventually we die fighting and before we let pathogens wreak havoc in the body, we rather take them down with us. That's our function."

"So you,…you would do that too." Her haemoglobin seemed to be twisting itself inside her chest at that thought, her cytoplasm apparently now replaced with something much colder.

There was a moment of hesitation, his voice low when he replied. "Yeah."

"Oh." Was all she managed to utter weakly.

He rubbed the back of his head. "It's not like I want to, I don't think any of us do, it's really more of desperate last-ditch effort. But if there really was no other way…" 4989 broke off, giving her a meaningful look as he bit down on his lower lip.

There was heavy silence following his words. At first AC could only stare until suddenly she just wrapped her arms around him.. She didn't know what to say. What could she say? Stay safe? Be careful? They sounded awful in her head, how much worse would they sound out loud? She didn't want him to die, especially not by his own hand. And after what happened to FP 1564…immediately she hugged him a little tighter, fingers digging into his uniform, leaving her standing on her toes. No, not him too.

But she had also noticed something else as well, making her remember something he'd told her the day FP had died. "Daily some of us die to protect this body. Some of them friends." She didn't know whether the ones who had sacrificed themselves today had been his friends, or even if he'd known them, yet she could still see how much their deaths affected him. AC had never seen him so sorrowful, so hurt.

And so AC 4293 just embraced him. She may only have known him for a while, but that didn't matter; she cared about him.

"AC?" He sounded so unsure, almost confused. Admittedly so far he'd been the one to hug her and she'd merely accepted the gesture, let him hold her closely as he consoled her.

This was the first time she hugged him and her cheeks flushed a little at that thought. "You were there for me when I needed it the most. What kind of friend would I be if I wasn't there for you?" AC had made up her mind; no matter what he thought, she did consider him a friend.

At first she got no reaction, as if he had frozen, until suddenly his arms were around her, squeezing her gently.

...

"You sure you don't need any first aid, Hakkekkyū-san?"

Slowly 1146 shook his head. "I assure you, I'm fine, Sekkekkyū. All I require are some fresh clothes and some rest." He mustered a smile. "You really mustn't worry."

She sighed. "That's easier said than done." The red haired erythrocyte told him as they walked together back to the blood vessel. "Want me to get you a tea, maybe something to eat while you clean up?" Always eager to help; it was something he loved about her.

And her offer did sound good. "I'd appreciate it, thanks." He told her calmly, feeling quite exhausted now that the rush he'd experienced during the battle had worn off.

AE 3803 smiled happily at that, the sight warming his mitochondria, and she grasped his wrist, apparently not caring that she got cytoplasm on her gloves, gently pulling him further. She'd never been deterred by his bloodied appearance after each battle, always first and foremost concerned for his wellbeing. If she could, she would move heaven and earth to make sure he was alright, of that he had no doubt.

1146 truly felt lucky to have her in his life, especially on days like this. Immune cells, most notably neutrophils died to defend this body and all living within, but so many intentionally sacrificing themselves undeniably weight upon him. One day he too might have to do the same, and AE 3803 was aware of that. And yet she'd decided not to leave him, for which he would be eternally grateful.

Together they continued to make their way across the field of debris, until something caught 1146's eye. Not far from them was one of his friend, but he wasn't alone either. He stopped, much to AE's confusion and nodded once towards his fellow neutrophil.

"Oh." She gasped surprised, a hand on her lips and 1146 suppressed a small chuckle.

U-4989 was being trapped in a tight embrace by the very erythrocyte he was trying so hard to befriend, hugging her in return. But it was his expression that amused the other white blood cell so much.

The fluffy haired neutrophil had always been one to openly show his emotions at any given time; he remembered 4989 breaking into tears when he had believed 1146 was about to die that day in the stomach and AE 3803 had mentioned that he'd cried upon learning how highly she thought of white blood cells, literally touched to tears. So seeing him cry a little now after all that had happened today wasn't that surprising. However when the two neutrophils made eye-contact 1146 also saw elation in those wide, grey eyes, before 4989 silently mouthed. "She's hugging me!" He seemed positively exhilarated.

AE 3803, who naturally had seen that as well giggled and gave an equally silent thumbs-up, while 1146 merely nodded, happy for his friend.

...

It was strange. AC 4293 had never been one to shy away from physical contact, but it surprised her just how comfortable she felt hugging 4989. Then again, given all that he'd done for her and just the way he was, it was so simple to be at ease around him.

Frankly she could have stayed a little longer in their snug embrace, when she picked up on something. "Are you crying?" The erythrocyte quietly asked, her voice a whisper.

She could have sworn she heard a sniff. "…no?"

AC smiled; he really could be so adorable. "I won't tell." She assured him, arms still around his neck, a hand stroking soothingly over his back.

Suddenly he rearranged his hold however and the erythrocyte felt him lift her up. Before she knew what was happening, 4989 started spinning, swinging her around in circles and AC laughed, closing her eyes in an attempt not to get dizzy. She hadn't been sure how he would react to her considering him a friend, but this reaction was better than anything she could have hoped for.

Eventually he stopped to put her back down on her feet again, still swaying a little himself. "Ouch." AC suddenly flinched as soon as she touched the ground; she'd completely forgotten about her injury for a moment.

Alarmed the neutrophil scanned her body. "Are you alright?"

She nodded, but lifted her foot, rubbing it carefully. "Another erythrocyte hit my foot with his cart while he was on the run. Nothing serious, it just hurts." However as soon as she'd finished her sentence, AC felt herself being lifted up again. This time he supported her back with one arm, while the other had found its way under her legs. "What are you doing?"

"Carrying you, obviously." 4989 told her, lips curving into a smile once more, though his eyes were still glinting from his tears. "You can't walk like this, not until someone's taken a look at your foot."

AC opened her mouth to reply something, but then chuckled amused. It really was sweet of him. "You're going to insist, aren't you?"

His smile turned into a grin, his big eyes now looking at her brightly. "Yep." But then he noticed something else. "Oh, I think I got some cytoplasm on you."

"What?" Momentarily confused by his suddenly sheepish expression, AC looked down. He was right, there was a lot on her jacket and shirt now, even her shorts had not been spared. "Ah; my bad." She'd been the one to hug him in the first place after all.

"Guess that means another visit to the wash station for you then." He noted.

The auburn haired erythrocyte shrugged and smiled, readjusting her arms so they settled around his neck once again; there wasn't a better place to hold onto really. "It's okay. Besides, now I got a chance at a rematch." That promised to be fun.

And if his bright smile was anything to go by he had no objections either. "You're on."

Chapter Text

Friendship

If someone had told AC 4293 a few weeks ago that she would be best friends with a neutrophil and be regularly hanging out with him, she would have taken that cell straight to the liver for detox.

But life was strange and now there was hardly a day when she didn't cross paths with 4989, who would eagerly join her on deliveries whenever he could, something that never failed to attracted a lot of puzzled looks, which embarrassed her a little, but didn't really seem to bother him.

Still, she couldn't deny that her days were a lot more fun with him around. She actually couldn't remember the last time she'd laughed so much or so often. Little by little he'd also begun to tell her stories from work, starting with the less gruesome ones, but always making sure to depict every battle as grand as possible, as if they were the epic tales of some great, classic saga and occasionally he would try to re-enact them as well. One time he'd even gotten some platelets to help him, letting them play the neutrophils, while he took the roll of the 'evil germ'.

It all had been quite fun and adorable, watching 4989 play with the platelets, until the one he'd carried on his shoulders had gotten a little too into character and hammered his little shovel too hard onto the neutrophil's head, when depicting the final blow. AC had spent the next ten minutes holding a cup with frozen glucose against the bump, while 4989 had tried his best to reassure a crying and very guilty feeling platelet that he was alright.

All in all, things certainly didn't get boring.

The only thing that worried AC were her friends, CT 2980 and AD 5022. Both of them would probably throw a tantrum if they were to see her being friends with a neutrophil, or rather several; after all, she met and talked with 4989's friends as well, if not as often. Given how they had reacted the first time seeing her just conversing with 4989, they'd probably be horrified. Thankfully, probably thanks to sheer luck, she hadn't encountered either of them, whenever she's been around neutrophils. Of course AC knew things couldn't stay like this forever, but for now she wasn't too keen on properly introducing everyone to each other. Somehow she had to slowly accustom her friends to the idea first. They had already noticed that something had changed and at least according to AD she was apparently smiling more nowadays.

Currently AC was leaving the lungs alone however, a box of fresh oxygen in arms, starting her new circulation. She'd made it about halfway down the pulmonary vein, when she was suddenly blinded, her vision covered by two, gloved hands.

"Guess who?" a merry voice asked her.

Warmth spread through her chest. "Oh, I wonder who it could be?" AC wondered aloud, chuckling a little. "You know there is that distinct scent of neutrophil soap."

"You narrowed it down to only a few thousand possible cells," came the teasing reply.

"Perhaps, but I also know your voice, 4989."

The hands were pulled back and she turned around. "The only fault in an otherwise flawless plan," the fluffy haired neutrophil lamented with feigned disappointment, but was ultimately unable to hide a playful smirk.

"So, how have you been?" There was something that looked like an almost healed cut along his left cheek, but otherwise he looked just as lively as always. Good.

He shrugged. "You know, just the usual pathogens straying into the body. Nothing we couldn't handle. You?"

AC lifted her box. "Busy as usual; right now I have to go to the left kidney."

This made his eyes light up. "Mind if I join you? I'm not on a set patrol, so I'm free to go anywhere at my own discretion."

"I'd love that." Suddenly the erythrocyte got an idea; it was right up his alley. "Hey, ever rode down the aorta?" she asked him excited.

Curiously he inclined his head, looking at her quizzically. "Rode?"

Smiling AC nodded towards the heart. "Come; it'll be fun."

A few minutes later AC was standing on the cart, rushing down the aorta, but where her oxygen should have been 4989 sat, box secure in his arms. Somehow she managed to navigate them safely between the other speeding carts, though she needed to keep a hand on her beret to prevent it from flying away, eyes narrowed due to the biting airstream. Still, both of them were yelling and laughing loudly, like two children on their first rollercoaster-ride. And this time AC didn't care if anyone looked, she was far too preoccupied and having way too much fun, and apparently so was he. Today started out great.

The next time AC was on a nutrients delivery alongside one of her friends, she got a reminder as to why she'd neglected to tell her them about 4989. As they walked along one of the body's many veins, the two erythrocytes came across a pair of neutrophils, currently disposing of a few germs, Pneumococci, fresh kills by the look of it. Their enzyme spray was doing its work, dissolving the violet bacteria, creating frizzling sounds and an acidic scent AC had become rather familiar with.

"That's revolting," CT 2980 remarked, looking quite disgusted at the half melted bodies as they passed by.

"Has to be done," AC merely replied. It wasn't like she enjoyed the sight; it simply just didn't bother her anymore. Frankly when you met a friend and his mates covered in red every other day, there wasn't much of choice. At least cytoplasm washed off easily.

Her friend frowned. "They could at least do it someplace else, not here on the main road for everyone to see," she noted, not entirely unreasonably. Still, the suggestion wasn't exactly practical.

"If you want to help them carry half a dozen germs around just to dissolve them, go head. I mean it's a lot more viable to do it right where they made the kill." They worked hard enough as it was; she'd seen them injured, exhausted from battle and even gotten a glimpse at a scar or two.

"Point taken." Suddenly she looked curiously at AC. "Since when doesn't this kind of thing disturb you anymore?"

Oh; how to explain that? "I guess after having been saved by a neutrophil more than once now, I just don't mind it so much anymore," the auburn haired erythrocyte told her with an innocent smile, hoping it was a convincing enough explanation.

Thankfully CT seemed to buy it, yet nonetheless regarded her friend with a concerned look. "You really have to be more careful, you know."

AC played with one of the messy strands framing her face. "It's not like I want these things to happen to me."

Playfully CT tugged at her friend's plait. "In any case, cut it out. We don't need new habits like that," she joked with an encouraging smile, while AC freed her plait from her friend's lose grasp; she'd never liked people touching her hair.

"I know; I'll try to do better," the auburn haired erythrocyte promised. Admittedly since the E. coli incident she hadn't actually encountered any germs, only ever seen the aftermaths, so that was something.

Her friend appeared satisfied with her responds. "Good; don't want one of those creepy leucocytes winnow you, because you got injured or something."

AC suppressed a sigh. Everyone knew that red blood cells too damaged or too old were removed from circulation, usually in the spleen. By now however AC had been through the regular check-ups several times and never had one of the macrophages even considered retiring her. Sure, the first few times after the parasite invasion she had been terrified, not knowing how the phagocytes would react to her scar, but by now she knew that she was perfectly functional.

That 4989 was so protective and caring towards her had only increased her confidence. By now she probably didn't even need to wear the bracelet anymore, but she liked it; it had been such a wonderfully thoughtful gift and AC had no intention of taking it off for that reason alone. No, she wasn't afraid of the phagocytes anymore, despite their almost manic drive to kill, whenever a pathogen was near. They weren't cruel or monstrous, not towards those they had sworn to protect, even with their lives, as she herself had witnessed.

But how could she make her friends see that, without having them go through everything she herself had? How change such a deeply ingrained image, when every time they took notice of a neutrophil he was usually bloodied, with a murderous glare in his eyes, which even AC still found unsettling, while screaming one of their battle cries?

Perhaps she could tell them a bit of what she got up to with 4989, without disclosing that he was a neutrophil? If she got them to develop a positive imagine of him, maybe the eventual revelation would be met with more acceptance. She had to try something. Sooner or later they would find out about 4989 and his friends, one way or another.

...

Meanwhile in a marginating pool 4989 was taking a break from his last patrol, high above the red blood cells travelling along the artery below, a still steaming tea next to him. With his back resting comfortably against the wall, feet up on a large buttress supporting the roof, he let his mind wander off. The past few weeks had been great. When he had first thought about befriending erythrocytes, improving the image of white blood cells and more specifically approach AC 4293, he'd never expected things to turn out quite like this. Not that he was disappointed, at least concerning the latter, on the contrary.

Ever since the battle against the E. coli, their relationship had made a dramatic leap forward. It seemed after every previous encounter had created cracks, on that day the ice had finally broken. Now when he approached her on the streets, AC greeted him with a warm smile, with no trace the apprehension that used to be ever present, talking with him as she would with any other friend. Even when he was still bloodied from battle, she didn't shy away, though that development had taken a bit more time. The first few times he'd seen her struggle to keep her face straight, but it seemed that she was now almost as used to it as AE 3803.

In fact, whenever they met shortly after an engagement she would first ask him about his wellbeing and he could see her swiftly checking him for injuries. 4989 just couldn't put into words how happy that made him. She actually cared, even worried for him, though perhaps given what had happened to her friend FP 1564 not that long ago, it was all too understandable.

Still, when she'd first hugged him on the battlefield after the E. coli had been dealt with, told him that she considered him a friend he'd been so elated. They had spent the rest of the day together, her company both welcomed and comforting. After such a day, after so much loss, simply talking with her had been helped him immensely. Now he understood even better why 1146 enjoyed his time with AE 3803 so much.

Perhaps it had something to do with their rather peaceful occupation, but there was a light-heartedness to these erythrocytes that was often difficult to find with most immune-cells, especially with AE 3803, who he had rarely ever seen without a smile.

Even AC, despite what she'd gone through since the Malaria-invasion and how she'd been affected by everything, was at least still quick to smile and laugh again, as well as empathetic to a fault. 4989 had also learned that she had a curious mind, asking about regions of the body she never or rarely got to see, or how leucocytes worked with each other and interacted when there wasn't an enemy to repel. Just the gory details weren't exactly her thing and were thus rarely addressed. Who knew, maybe in the future.

In turn she had also truly opened up to him. Among others he'd learned of her friends, what they were like and her hope to introduce him one day. He now knew of her wish to see the REM-sleep unfold in the brain and her weakness for several sweets, among them fresh buns from a shop at the nasal cavities, something he all too well understood; they were delicious. Many of the others he planned to try out, when he got the chance.

She also got along very well with the other three, even though AC still seemed unsure as to where she should look when speaking with 2626; the lack of visible eyes amusingly seemed to throw her off a little.

All in all, despite him not having really gotten closer to easing relations between immune cells and none-immune cells, 4989 looked back happily at these past few weeks and looked forward to what the next few would bring.

A few days later AC found herself walking through the venules near the spine, carrying a heavy box of CO2 she'd just received from a tissue cell. There was very little traffic between the high apartment buildings at the moment, but she could hear chatter from some of the balconies, even music from an open window somewhere above. It was really inviting just to stay around for a while and listen, before she would head further to the busy vein just a few more blocks away, but it was then that she picked up on someone close by already whistling along to the tune.

Curiously AC headed further down the road and looked around the next corner. Uphill on the street, at the very top of the elevation she spotted a cell dressed in white, crouching, though from this angle the erythrocyte couldn't quite see why. Had he just killed a bacterium?

In that moment he stood up and AC's haemoglobin jumped, when she discovered it was none other than 4989.

Delighted the auburn haired erythrocyte jogged uphill to greet him, seeing him turn as he noticed he was being approached, smiling when he recognized her. "AC!" he greeted her enthusiastically, waving, clearly just as happy to see her.

"Hi, 4989." She reached the top and saw that curiously he was standing next to an empty erythrocyte delivery cart. "What are you doing here?"

"Seeing how fast I can get down this road," the neutrophil simply replied, pointing down the empty street.

AC raised an eyebrow. "Why do I get the feeling you're looking into the offensive applications of our delivery carts." She had already borne witness to some of his more improvised weapons. There were hits and misses, and this looked like the latter.

Her questioning expression seemed to surprise him a little. "What? Hunting down bacteria can be a hassle, no one wants them to escape, plus with the right velocity it might be possible to just run them straight over," 4989 explained excitedly.

She hated to do this. "Yeah, I'm going to have to step in here."

"Huh?"

"You just can't do that."

Now he really did seem confused. "Why not? How is it different from what we did in the aorta?"

"Because the aorta is a vessel designed for blood to flow through at high speed and under great pressure. In a vessel like this you're only going to cause damage, might hit an innocent bystander. Also we didn't run over any bacteria," AC told him, feeling a little guilty, given that she had inspired this particular idea and was now crushing it. But she just had to dissuade him from doing something so risky. Not to mention that these carts were notoriously difficult to steer, if you intended to do anything else but go straight forward.

He looked at her pleadingly with big, round eyes, hands clasped. Oh, why did it have to look so cute? "At least a test run, just to see if it could work?" No, she had to stay strong.

AC put her box aside and stepped in front of the cart, arms akimbo. "If you want to run me over."

For a moment he stared at her stunned, but then his eyes narrowed, while his mouth turned into a thin line. "You don't play fair."

The erythrocyte grinned triumphantly. "Then I win?" But seeing how disappointed he was, she gave him an encouraging smile. "Look, if it's an immediate emergency, grab one and drive it straight into a germ's face for all I care, but we're not making it a standard, alright?"

4989 sighed defeated. "Fine."

AC stepped closer and placed a hand on his chest, her voice soft as she spoke to him. "Hey, I don't want to hear stories one day about how a crazy neutrophil crashed into some poor cell's living room."

Now it was his turn to raise an eyebrow questioningly. "Crazy?"

"Eccentric?" AC offered in return.

He paused, pondering this for a moment. "I'll concede to that."

This made her chuckle and she could see him smile again. Suddenly she had an idea. "How about this; there are some regions in different bones, which are no longer producing new blood cells. They have undergone a bit of reconstruction, but they are rather low-traffic areas."

His eyes lit up, his smile broadening. "You think I could try it out there?" 4989 asked hopefully.

"Under the supervision of a more experienced driver, of course." AC gave him a meaningful wink. "Deal?"

He grinned. "Deal."

Satisfied with having resolved the situation, AC picked up the CO2 again. "Good; I'll be taking this then, thank you." And put said box on the cart.

"Don't you trust me?" 4989 asked, clearly only acting a little insulted, head tilted sideways, once more looking at her with big, puppy eyes.

It was still adorable, but he'd already used it today, therefore all she gave him a knowing smile. "Oh, I trust you…to get up to some mischief."

"Hey!"

AC gave him a rather piercing look, even though she kept smiling. "Am I wrong?"

Sheepishly he looked to the sky, tapping his index fingers against each other. "…not necessarily," he sheepishly admitted, making her chuckle.

She was however interrupted by a voice from his transceiver. "U-4989, you hear me?"

Quickly he grabbed the device, putting on a much more serious expression. "Loud and clear 2626. Got something?"

"Trouble at the paranasal sinuses. Can you get up here?"

"On my way." 4989 gave her an apologetic look. "Sorry, gotta run."

AC merely shrugged; it couldn't be helped. "Don't worry, just be careful alright?"

He smiled again. "Promise! See ya!"

"Good luck!" the erythrocyte shouted after him as he ran off down the hill, and soon he was out of view. Time for her to get back to work as well.

…

Some time later AC left the heart and finally reached the lungs. She made her way through the crowd of fellow red blood cells, before entering the network of capillaries spanning the alveoli, exchanging her CO2 for a new box of oxygen. Curious she looked at the new address; seems like she'd be visiting a cell of the cheek muscles. A good excuse to take a little detour and visit the nasal cavities again.

Satisfied with her new destination, AC left the little room where she'd exchanged gases and headed for the elevators. Luckily there was currently on this floor, another erythrocyte entering it. "Hold the lift!" she shouted and started running.

"Sure," came the reply and a red-haired erythrocytes put her hand against the elevator door, stopping it from closing.

Hurrying up AC made it, practically jumping inside. "Thanks."

"No problem," the other red blood cell chirped, a friendly smile on her lips. She was maybe half a head shorter than AC and had almost chin-long, red hair, with a single curl standing up.

"AE 3803?" She looked at the beret and indeed, there was her number.

"Yeah?"

AC smiled. "Sorry, you probably don't remember, but I was one of the other red bloods cells who got a bracelet from AB 2934." The word 'parasite' had been on the tip of her tongue for a moment, but that particular term just made her skin crawl.

Meanwhile AE's eyes widened. "Oh!" she exclaimed and quickly apologized. "I'm so sorry I didn't recognise you."

The auburn haired erythrocyte shook her head. "It's alright; that was weeks ago and it's not like we had a chance to talk back then." If it hadn't been for that distinct hair curl, and having seen her around U-1146 that one time, she probably wouldn't have recognized AE either. "Glad you recovered."

The other erythrocyte smiled again. "Thanks, you too. I guess you got found quickly as well?"

"Not exactly," AC admitted, just as the elevator's door finally closed.

"Huh?"

The auburn-haired cell took a deep breath. "Well, I was close to the stomach when I came across a commotion in the blood vessel. I checked what was going on and saw AB 2934 on the ground, unconscious…perhaps she was already dead." It was an image she would never be able to forget. "I was shocked, paralysed actually, and then shortly after two neutrophils and a NK cell showed up. They examined 2934's body, but had no idea what was going on…until her bracelet moved. They killed each parasite before anyone else could get infected, but it took me a while to snap out of my state of shock, knowing I had the same thing on my wrist. I was desperate and begged for their help. I had never been so afraid before in my life," she confessed. "They teach you how to run from bacteria, but never prepare you for stuff like that."

"That's when you met U-4989?" AE carefully inquired

AC smiled and nodded. "Yes; he immediately tried to get it off me and when the NK-cell suggested to…eliminate me, he and 1146 stepped between us without hesitation. They convinced her to at least try to cut it off. That's how we found out it could be removed." Afterwards 4989 had brought her to the bone marrow for recovery, before joining the search for the Plasmodium falciparum. It still had taken her far too long to do what she should have done that day. Thank him. Frankly now, she felt silly for originally having been so afraid of him.

"And then you told 1146 about me," AE 3803 concluded, flushing a little.

"He asked me who else got one, and there were only two others I knew off." Curiously she looked at the redhead. "Never would have expected his reaction though."

To her amusement, AE's cheeks turned a darker shade of red. "Do you know if the other one made it too?" she quickly asked.

"RD was how her designation began I think," AC thought aloud. "To be honest I don't know; I haven't seen her since. But given how many of us there are that doesn't necessarily mean anything."

AE 3803 nodded, but looked a little worried. "True. I hope she made it though."

"Yeah." AC then shook her head. "Wow that was a bit dark. Let me try this again." With a smile she bowed her head to her fellow erythrocyte. "Hi, I'm AC 4293; nice to meet you."

The redhead giggled and bowed as well. "Hi, AE 3803…but you already knew that."

The elevator door opened again and together the two erythrocytes exited into one of the halls where several of the lung's venules and capillaries flowed into, joining together into one vessel. The vein that started here would later merge with others, until all were united into the large pulmonary vein, leading the blood back into the heart.

As they crossed the hall, AC picked up their conversation again. "Hey, can I ask you something?" Actually there were a few things she was curious about.

"Sure."

"4989 told me you and U-1146 are close, not just that you're together, but that you've been friends pretty much ever since you've started working in the blood vessels."

Once again the other erythrocyte suddenly turned bright red. "You could say that," she admitted somewhat evasively.

Still, AC pressed on. "May I ask how your friends reacted? You know, the other erythrocytes." If she'd gone through the same situation AC now found herself in, maybe she could help. She would appreciate any advice really.

"Frankly, I never really had many friends," AE told her apologetically, scratching her cheek with a finger. "I had my senpai, but most others tended to make fun of me for making mistakes, but mostly for getting lost. Those I did occasionally speak with were usually confused that I spend so much time around a neutrophil." She looked at the auburn haired erythrocyte curiously, but also with a bit of concern. "Why? Did your friends say something?"

AC tugged at some of the strands framing her face. "Well, a few of them are shall we say…a little prejudiced."

"And they don't like you being friends with 4989?"

"As of now they don't know," AC admitted, feeling a little abashed. "I've been wondering how to tell them. I mean it would be awkward if they just saw me together with 4989." And she was not keen on the conversation that would follow.

"My senpai actually encouraged me to be honest with 1146," the redhead confessed. "Sure, she found it strange, still does, but she was never…against it. Maybe because she knew how often he's saved me, or helped me out when I was lost."

"Considering how often 4989 has been there for me, I wish I could make them see that they are not terrible people." She sighed. "4989, 1146, 2626, 2048; they've all been so kind, but my friends have that bloodthirsty image of leucocytes that just seems to get reinforced every time they see one of them on the job."

"Sorry I couldn't help," AE apologized.

Quickly AC shook her head, though admittedly feeling just a little disappointed. "Don't worry," she told her and put on a genuine smile. "But it's nice to finally talk with someone who too doesn't think their just killers." Someone else who knew how they really were.

AE beamed happily at that. "Likewise."

"Let me through!"

Many of the erythrocytes leaped aside as 4989 rushed down the road in hot pursuit. Through a small opening in the sinuses several germs had gotten into the body proper and while most of the pathogenic bacteria had been taken care of, some other bacteria, which commonly were merely commensals, had also made it inside where they certainly did not belong; here they would only cause damage.

Commensalism

A commensal is a life from that closely interacts and benefits from another, but without harming it like a parasite, or having the other life form benefit in return like in a mutualistic relationship. An example would be the countless bacteria living on the surfaces of our bodies, like the skin, which are usually harmless, and but have among them facultative pathogenic/opportunistic species.

4989 was following one such germ, Staphylococcus epidermidis, her fear of him only spurring her on. He was gaining on her however several minutes into his pursuit, her beige body sticking out between the red blood cells, the surface of her membrane shimmering due to the sticky biofilm, and she too realized that. In her desperation she suddenly grabbed one of the surrounding erythrocytes, the rest of them dispersing, screaming.

"Ah!"

"No!" another one called out, but did not dare approach, as the bacterium pulled the female red blood cell towards herself, using her as a shield. The Staph had her back turned towards a building's outer wall, making sure she could not be flanked. Her claws were against the black haired erythrocyte's throat.

4989's pupils shrunk, the sight sparking disgust and fury within him. "You have some nerve," he snarled, baring his teeth, blade lifted to strike.

"Stay back! Or I'll haemolyse this erythrocyte!" The bacterium dug her dark claws a little into the membrane of her hostage, not yet breaking it though. The erythrocyte whimpered fearfully, closing her eyes, a tear now running from one of them across her cheek.

"And then what?" 4989 barked back. "What will you do without a hostage?"

The Staphylococcus hesitated for a moment, clearly not having thought that far ahead. Meanwhile the neutrophil considered his options; attack the germ directly would only endanger the red blood cell, likely mean her death, something he wouldn't risk unless there was no other way. Somehow he had to force the germ to release her. Suddenly the bacterium's swaying tail caught his eye.

Finally the Staph had come up with a retort. "Why don't I keep killing them?" Her eyes narrowed. "Though I suppose you won't care as long as you get to kill me, neutrophil. I'm right, aren't I?" And her claws dug a little deeper into his hostage's throat, drops of red emerging.

With his free hand 4989 slowly reached for his throwing knives. "Don't you dare!"

"Then leave me be!" she demanded. "I will not be killed today."

"Then you should have stayed outside," 4989 snapped back and with a swift move of the wrist released one of his knives.

The small blade embedded itself deeply into the bacterium's tail, pinning it to the wall, the beige creature responding with a cry of pain. And a loosening of her grip.

Without a moment of hesitation, 4989 dashed forth. He took hold of one of the erythrocyte's arms and pulled her close against his chest. His other arm went over the dark haired cell's head, knife in hand, straight towards the germ's throat.

The pain hadn't distracted it for long though and it managed to block the attack, using both its clawed hands. Quickly 4989 pushed the erythrocyte behind him and drew a second knife. This time it wasn't fast enough. His blade cut open the Staph's abdomen and then slashed upward across the torso, cutting it open, finishing the kill. Bright red cytoplasm sprayed forth from the massive injury, covering the neutrophil's front completely, head to toe.

The Staphylococcus collapsed, utterly drained as it seemed and 4989 took a deep breath to calm himself down, putting his blades away again. With a hand he wiped across his face, trying to get some of the prokaryotic 'blood' off, noticing that the short strands of hair surrounding it, peeking out from under his cap, were soaked as well.

Finally he turned around to check on the red blood cell's condition.

She was cowering on the ground behind him and now that he got a better look at her, 4989 recognized her. His eyes darted to her beret ; CT 2980. He'd just saved one of AC's childhood friends.

"Are you alright, miss?" the fluffy haired neutrophil asked carefully due to her state of shock, kneeling down in front of her.

His voice seemed to jolt her back into reality. "Ah!" She leaned back away from him, her voice shaky as she spoke. "Yes, yes! I'm perfectly fine." Her eyes were still filled with horror. But they were not looking at the germ; she was staring wide-eyed straight at him.

"CT! Are you hurt?" Another red blood cell, the one who had cried out earlier rushed to her side. AD 5022 according to the little round tag.

"Just a scratch I think." CT 2980 replied weakly as her friend helped her back to her feet.

"Might I…" 4989 carefully began.

"We're fine!" The male erythrocyte hastily insisted, pulling his friend closer as they both stepped back. He even covered his friend's wound with a hand.

4989 actually flinched at that. Everyone knew that erythrocytes that got hurt too badly were removed from circulation; did they really think he would do that to her because of some scratches at her throat? Looking at their fearful faces he didn't need to ask.

Hurt he could only watch as the two erythrocytes all but fled back into the blood stream, disappearing into the crowd. 4989 looked around to the audience battles usually attracted. Commonly he didn't pay much attention to them, mostly because he tended to be occupied with other things, but now he took his time. Fear, disgust, uneasiness, only to name a few; it was lysosome-wrenching to take them all in. The cells around him, mostly other erythrocytes noticed that they had his attention and quickly dispersed again, hurrying along, leaving 4989 still kneeling there next to his kill, feeling strangely hollow.

AC 4293 and AE 3803 were still on their way towards the pulmonary vein and continued to chat, getting to know each other a little better. AC got the impression that while a bit scatty at times, at least from what AE herself told her, the redhead was a very kind-hearted and upbeat cell. Not to mention incredibly passionate about her job; despite mentioning her short comings so often, there was a determination that was actually quite admirable. AC of course liked her job, but she couldn't deny that deliveries all day could occasionally be rather boring…unless 4989 was around.

"Hey, what do you think about getting a bite to eat before starting with the circulation proper?" the auburn haired suggested. "I know a vendor in the pulmonary vein, who makes excellent daifuku."

"Oh, sounds great." Erythrocytes very rarely said no to any kind of confection; every single one of them was a sweet tooth, as glucose was their only source of energy.

Apparently AE 3803 wanted to say something else, but both erythrocytes stopped, when they heard some commotion behind them. "What's going on there?" AC wondered aloud and frowned.

Suddenly they heard shouting, the crowd of red blood cells hastily parted and… "Get down!" The redhead quickly threw herself at AC getting her out of harm's way, before something leaped over them, its claws missing them by mere inches. Whatever it wsimply ignored them and continued to run.

"Thanks AE." AC gasped, suddenly finding herself sitting on the ground, next to the shorter erythrocyte.

"No problem; this kinda happens all the time" came the meek reply, accompanied by a small smile. "What was that though?"

In all likelihood it had been a pathogen from outside, these were the lungs after all, but which one? Looking after it, AC caught sight of a spider-like creature covered in white fur with pink patterns.

Moraxella catarrhalis

Moraxella cartarralis, formerly known as Branhamella and/or Neisseria catarrhalis is a diplococcic bacterium and lives commensalistic as part the mucosal flora of the human upper respiratory tract. As a facultative pathogenic bacterium it can cause sinusitis, bronchitis, pneumonia, Otitis media among others if displaced.

"No idea," AE confessed as the two got back on their feet. "But surely there has to be a white blood cell around to deal with it."

In that moment a tall cell emerged from the crowd and stepped into the fleeing bacterium's path. Swiftly the cell brought down what appeared to be a pole arm of sorts, the top crushing down on the germ's back with great ferocity. And that was all it took. The bacterium crumbled and lay motionless at the immune cell's feet.

It appeared to be a macrophage, yet her dress wasn't quite as wide and was of a pale blue colour, while there was a dust mask currently hanging around her neck. Her weapon was a bit strange looking, a pole-arm that looked like a mix between a maul and a broom. Despite the small diameter of the hammerhead, or maybe because of that, it had carved a deep hole into the germ's back. "My, my; that one almost got away there."

Alveolar macrophages

A specialized type of macrophages found in the pulmonary alveoli, responsible for the removal of not only microorganisms such as invading bacteria, but also that of dead particles such as dust, which is why they are also known as 'dust cells'. They can also release lysosomes and antimicrobial peptides to deal with invaders, as well as call in circulating white blood cells such as neutrophils for support and cause an inflammatory response.

Calmly, unbothered by her now bloodied dress, she took out her transceiver. "Here is Alveolar Macrophage. The escaping bacterium has been neutralized and the route to the heart has been secured." She chirped merrily.

It was strange. Everyone seemed to fear neutrophils and most lymphocytes, but for some reason no one seemed to be too disturbed by the macrophages, who always smiled, even when they killed. It truly puzzled AC now that she thought about it; yeah, neutrophils looked intense, but macrophages seemed to enjoy it. Was it maybe because erythrocytes were raised in part by macrophages, so such fears never developed?

Her train of thoughts was however soon interrupted, when she heard a familiar voice behind her and AE 3803 hastily jumped to her feet. "Sekkekkyū!" Getting up herself, AC turned around and spotted U-1146 making his way through the crowd, or more accurately, dividing it with his bloodied appearance alone. He'd probably been involved in the same battle that spider-like germ had tried to escape from, given the direction he was coming from.

AE's cheeks flushed red and excitedly she waved at him. "Hakkekkyū-san!"

The neutrophil reached them and seeing that the threat had been dealt with, he put his knife away. "Sekkekkyū, are you alright?" Worriedly he examined AE for any injuries, though refrained from touching her with his red, dripping gloves.

"I'm fine, not even a scratch," the redhead quickly assured him, putting on a warm smile.

"What about you, AC 4293?" he asked, addressing the auburn haired erythrocyte.

"Oh, me? Same, thank you for asking."

Apparently satisfied with her answer 1146 turned back to AE 3803. As they started to talk with each other, AE beaming, offering him a tissue to at the very least clean up his face, 1146 looking at her with a soft, affectionate smile, AC couldn't help but think that 4989 had been right; they were cute together. Romantic relationships were a rare thing among cells, and gestures of affection were often not exchanged in plain view, but that an erythrocyte and a neutrophil had somehow found together surely had to be unique. And one could plainly see the affection the two had for each other.

And suddenly AC felt misplaced; maybe it would be best to leave those two alone, she really was just a third wheel here. "Well I better get going," she excused herself, drawing the two's attention. "It was nice meeting you, AE 3803."

The redhead nodded happily. "You too, AC 4293. Have a good day," she wished her brightly, waving goodbye

"You two as well." AC replied, smiling back and picked up her box. "Bye!" Hopefully there would be a next time.

He'd really screwed up, hadn't he? So much for winning hearts and minds.

4989 was crouching next to the slain Staphylococcus and reached for his enzyme spray. He hesitated for a moment, fingers lingering on the pocket's clasp, but eventually he took it out nonetheless. After terrifying those two erythrocytes, and after seeing all those other red blood cells, he'd kind of lost his appetite. Better just dissolve it.

AC had mentioned that her friends were like most a little fearful towards leucocytes, but he never would have expected such a reaction from the two of them. Did he really look that scary, when he fought? They'd been as frightened of him as they'd been of that germ; the memory of that image alone was enough to give him a painfully tight feeling in his chest. His duty was to protect, they had to know that...right?

Some of the currently passing erythrocytes briefly stopped to watch for a moment as he began to dissolve the bacterium. He could hear them, despite the lowered voices, just like countless times before. Only that today he couldn't help but actually pay attention.

"Ugh, that's so disgusting."

"Look at all that cytoplasm. Brutal."

"What do you expect; it's a white blood cell after all. They are merciless."

"So creepy."

No he didn't hear that. Any of that.

He bit his lower lip, trying to focus on his task at hand and blank everything else out. Just dissolve the germs as usual. This kind of talk had never bothered him all that much before, it shouldn't now…even if he knew now that it didn't have to be this way.

"Let's give him a wide berth. You never know with them, maybe he'll lash out."

"Yeah, I've seen them in battle once, it's insane. They are insane."

"Why can't they stay in the lymphatic system too, like the lymphocytes? It's irresponsible to have killers like them around normal blood cells."

Freaks, abnormalities, killers, assassins; he had all this before. Had he been an idiot to think that perhaps he could have changed that attitude? Their job was to dispose of all threats…violently. He couldn't change that. That was how things were.

"4989!"

That voice jolted him out of his dark thoughts.

AC. She sounded so joyful.

4989 looked up as he got back to his feet and saw her jogging towards him, a smile on her lips and a box of oxygen in her arms, that plait of hers swaying left and right with each step. Yet all he could do was to stare blankly at the erythrocyte as she put her box aside. "You're okay?" She tugged at one of the bloody strands of hair, getting it away from his eye. "That prokaryotic cytoplasm really does go everywhere, huh?" AC asked with a chuckled. There wasn't even a hint of disgust, neither in her voice nor her expression.

Now he really wanted to cry, his lower lip trembled.

But he didn't. Somehow. Instead he quickly wrapped his arms around her; he was so glad she was here. He just really needed to hold her right now.

While he occasionally liked to greet her with a hug, this time he appeared to have taken her by surprise. "Hey, you're alright Hachikyu-kun?" She sounded confused; maybe because he hadn't actually said anything yet, which was admittedly unusual.

He took a deep breath and gently squeezed her a little tighter for a moment before releasing her from his embrace. Quickly he readjusted his cap, trying to sneakily wipe away a few treacherous tears from his eyes without her noticing. "Yeah, I'm fine. Just happy to see you." And he really was right now and so indescribably grateful. Then he picked up on something. "Hachikyu?" He was a bit puzzled that she'd only used his last two digits.

"Just trying something out; my friends and I would always shorten our names, in part for convenience," she told him. "I can go back to '4989', if you don't like it."

Quickly the fluffy haired neutrophil shook his head. "No, no; it's just I never had someone call me that before," he explained and mustered a smile. "I like it." It certainly felt more personal.

The auburn haired erythrocyte seemed content with this and smiled back. "Good. Oh, and you owe me a tea."

For a moment he was baffled. "Huh?" What had he missed?

AC didn't answer, but merely pointed at her now bloodied shirt, giving him a meaningful, yet somewhat amused look. Oops.

4989 laughed sheepishly, rubbing the back of his head. "Hehe; third time's the charm?" He really needed to watch that; thankfully she was very forgiving.

"Maybe I should ask an intestinal cell for an apron next time I'm down there," the auburn haired erythrocyte mused aloud, checking the rest of her clothing. Even though it wasn't too noticeable on the red jacket, one could still see where his arms had been when he'd hugged her.

His cheeks warmed. "Sorry."

But AC only chuckled and tapped his nose with one of her fingers, still smiling softly at him. "Get me a warm tea afterwards and we're fine." Right now he'd get her anything she wanted.

Chapter Text

Trust

Among all the places of the body, the spleen was probably AC's least favourite one, but every erythrocyte had to come here for regular check-ups, to see if they were healthy and functioning. Those who weren't…well, they were taken care of and recycled so there could be new red blood cells. It was of course an unavoidable fate, but everyone hoped to have at least grown old and so face it after a long, satisfying life, instead of being winnowed prematurely because of some defect.

Thankfully her healed scar had proven to be no problem, nonetheless AC couldn't help but feel uncomfortable whenever she came here.

She tensely went through the tests, examining the condition of her membrane as well as her ability to squeeze through even the tiniest capillaries. While her face was still flushed from the latter, the macrophage gave her a thumbs-up, wishing her a good day with a warm smile, before leaving to attend to the next erythrocyte, much to AC's relief. She readjusted her uniform and left the building a little quicker than necessary, glad to be done.

The auburn haired erythrocyte stepped out into the bright open, only to be greeted by a white clad cell waving at her from across the street.

Elated AC jogged over to him, her earlier tension immediately all but forgotten. "4989, what are you doing here?" she greeted her friend; had he waited here for her?

The neutrophil smiled at her in return. "I know you hate the check-ups in the spleen, so when I saw you walk in I thought I'd stick around." He explained, before he held up a little paper bag. "And I may have gotten you a little something to cheer you up."

AC immediately picked up the sweet scent of baked goods and curiously checked the bag, which she found contained several fresh buns, still warm. "You shouldn't have," she told him, but still smiled gratefully.

"Oh, so I get to keep it?" 4989 asked brightly with a wink, reaching for the bag again.

Quickly AC hid it behind her back, now giving him a playful smirk, skipping away just out of reach. "Too late; a gift is a gift," she reminded him merrily. "But you are welcome to have some."

…

The two cells made themselves comfortable in a nearby park, finding a quiet little spot among the trees that provided a bit of privacy. When spending the entire day on busy roads among millions it was nice to get away once in a while, take a breather, and it allowed 4989 to tinker undisturbed on his newest little project.

AC sat facing him, eating her buns, curiously watching him. He however was a little too preoccupied, only having taken a single bite off his one so far.

"Your tea is getting cold," she reminded him, after taking a sip from her own cup.

4989 looked up, momentarily confused. "Huh? Oh, right." The beverage his friend had gotten him on their way here had completely slipped his mind.

"What exactly are you working on this time?" AC asked him as he drank some tea, fortunately finding it still decently warm.

"An upgrade on the spear," He explained as he put the cup aside again. "It's effective, but I think I can make it better." Frankly right now it didn't look like much, as he was still properly attaching his first knife to the pipe. It seemed like an easy thing, but if not done right, the blade would simply fly off at the first strike. The weapon needed to survive the heat of battle; slashes, stabs and parries, no matter the angle or the toughness of the enemy's cell wall.

Thoughtfully the auburn haired erythrocyte regarded the work in progress. "I've seen macrophages carrying lots of two-handed weapons. Why aren't neutrophils equipped with them, if they're that effective?"

4989 shrugged, as he tested the stability of the blade. "Probably has something to do with resources; it's easier to mass-produce knives for a few thousand neutrophils than large pole arms. Plus migrating is a bit easier, trust me I've tried, and we're supposed to get anywhere quickly. And of course you are faster with knifes than with a bulky two-handed weapon, which does have certain advantages, depending on the pathogen."

"Then why make a bulky, two-handed weapon?"

His lips curved into a smile. "Hey, it's my job to defend this world; why not use everything at my disposal?"

"Won't you get into trouble?" The neutrophil could hear concern lingering in her voice.

Frankly he wasn't too worried; he'd been doing this his entire life after all, though admittedly his teachers had always tried to knock that habit out of him. His colleagues in the field were a bit different. "Not as long as only pathogens get hurt," he assured her. "But if I hurt anyone else, or damage something I shouldn't have, I'd get into trouble no matter the weapon."

"Point taken."

"There."

Curiously AC tilted her head a little to the left. "So; your big innovation is one blade at each side?" He had indeed attached a knife to each end of a pipe.

"You don't sound impressed," 4989 noted somewhat disappointed and stood; sure it wasn't anything mind-blowing, but still. "This could really come in handy, when I'm surrounded, or when there's a horde like during a virus infection." He swung his new weapon around, testing it out, after making sure she was out of its reach.

His friend watched him for a while. "I get that," she slowly began, now looking concerned again, which dampened his mood somewhat. "But you just mentioned getting into trouble should you harm anything but a pathogen. So I can't help but wonder what happens if there's another cell nearby, like a fellow neutrophil. I mean at least one of those blades you won't be able to see, and you guys are often fighting side by side. If you swing it around…" She had a point.

4989 squinted his eyes. "You're secretly my conscience, aren't you?"

Much to his delight AC laughed in response. "Yes; I'm so glad we finally get to meet," she joked teasingly. "But seriously, isn't that thing a bit dangerous?"

4989 sat back down in front of her, giving her a reassuring smile. "Well, I need to practise of course." He still believed this could work, especially when he was on his own against numerous enemies. What he needed was experience and a good place to train. His mind drifted off as he considered his options.

"Not alone."

Surprisingly quickly, AC suddenly grabbed the spear and pulled it from his loose gasp. "Hey! Give that back!" Alarmed 4989 reached for it, but she was holding his weapon up with both hands, just out of his reach.

"Only if you get your friends' approval and practise with them," she declared, stretching both body and arms as much as possible to stay in the possession of the spear.

Frankly he hardly heard what she said, reaching up with his arms and fingers as far as he could, almost touching the pipe now. "AC-chan!" he pleaded, as she leaned back, determined to keep the weapon out of his reach.

"You have to promise me."

He didn't want to tackle her, or do anything really that could hurt her. But then again maybe he didn't need to. With a mischievous glint in his eyes he lowered his hands again, and instead of going for his spear they now went for her sides. By pure accident had he discovered one day that she was ticklish, a fact that now simply begged to be exploited.

His fingers moved swiftly and AC screeched surprised. Instinctively she pulled her arms down, trying to protect her sides, shield them and…WHAM!

Still holding the spear with both hands, the part of the staff between them crashed down on 4989's head, which just so happened to be in its path. His vision went black for a second and he saw stars, immediately stopping to tickle her, as pain radiated through his head.

"Oh gosh, I'm so sorry!" He heard AC exclaimed shocked.

The neutrophil rubbed his aching head and groaned. "Ouch," he muttered. "Guess I deserved that."

"You're alright?" 4989 opened his eyes and looked up, seeing that she had put the weapon aside on the lawn, one hand now covering her mouth, watching him worriedly and with guilt. He hated to see the latter.

"Yeah," he assured her, remorseful for making her feel bad, and mustered a grin. "Didn't know an erythrocyte could pack a punch like that."

"Well, we do carry around heavy cargo all day long," AC pointed out, though clearly relieved now. "Again, sorry."

"Sorry enough to give me back my weapon?" 4989 asked hopefully, tilting his head sideways.

The auburn haired erythrocyte raised an eyebrow. "You're not gonna use it for now?"

It was disappointing, but she wasn't completely against him using it after all. "Promise."

"And you're sorry for tickling me?"

Innocently he looked away to the ground. "…maybe a little."

"Hachikyu-kun." She sounded quite stern, though as he could see from the corner of his eye, her mouth was curving into a smile, telling him that in truth she wasn't actually angry.

Still, he gave her his best and biggest puppy eyes, lowering his head to look smaller and penitent. "Very sorry." And he so adored that smile he was rewarded with.

The following days were rather calm for the body as a whole, with no major invasions or injuries. On one delivery to a cell in the connective tissue of the shoulder, AC spotted a familiar looking white blood cell overlooking the traffic. It was not 4989 however.

The neutrophil soon spotted her as well, greeting the erythrocyte upon her approach with a smile and a hat tip. "Hi, AC 4293."

"Good so see you again, 2626," she greeted him. "Hope you've been well."

"Can't complain," he replied before starting to chuckle a little. "I'd ask how you're doing, but given that 4989 has been in an almost obnoxiously good mood, I don't think I need to."

She couldn't help but blush a little. "And there I worried that I've been a bit of a spoilsport recently," the auburn haired erythrocyte admitted.

"Why is that?" She wondered if he frowned behind those bangs, covering both his eyes completely, but at least his head was ever so slightly tilted.

AC tugged at one of the wild strands framing her face. "I may have 'discouraged' some of his ideas and…experimental weapons."

"Don't worry about that: we've all done it," 2626 told her with a shrug.

"Really?"

"Oh yes," the neutrophil confirmed. "Remember; the four of us have been friends since childhood and he's been 'improvising' since the very beginning. He may pout sometimes, when he really liked an idea, but he always bounces back as soon as the subject changes."

She chuckled. "True enough." It was an aspect she truly liked about him.

"You should ask him about the time he tried to build a bow."

"I both intrigued and horrified," AC admitted, imagining all the ways that could have gone wrong.

2626 laughed. "Sounds about right," he confirmed. "In any case don't hesitate to rein him in whenever you feel necessary; he may not be as reckless as 1146 can be, but he doesn't always think things through."

"Noted."

...

Meanwhile in an artery along the jaw U-4989 found himself in the company of another of his friends.

"It's been a while, since last we went on patrol together," U-2048 commented as road started to go a little uphill, approaching one of the teeth.

"Yeah, had to do a lot on my own recently," the fluffy haired neutrophil admitted. Aside from the fact that most neutrophils went alone on patrol regularly, only teaming up for the most threatened parts of the body, the E. coli invasion had left their forces somewhat shorthanded. They were recovering, but that meant that more experienced neutrophils were now almost exclusively paired with rookies, rather than with each other.

To his surprise his friend however grinned. "That and you've been running off a lot to go look for your erythrocyte-friend."

"Sorry." He just really liked spending time with her, and unlike 1146 once with AE 3803 he didn't rely on running into her randomly.

2048 chuckled. "I'm sure we'll survive." He looked ahead and frowned. "What's going on up there?"

Curious 4989 craned his neck to see what his friend was referring to, and spotted a group of Thrombocytes up the road, their blue shirts standing out despite them being so small. As they approached, the two neutrophils saw that there had been a hole in the wall and ceiling of the artery, now covered with nets of fibrin and the unlucky erythrocytes trapped in them.

Small injuries in the mouth, especially around the teeth weren't uncommon; they were a regular, almost daily occurrence, so neither immune cell was surprise that they had come across one.

"Hello, Platelets," the fluffy haired neutrophil greeted them warmly upon reaching the site, waving when the children turned around. "What happened here?"

The leader, a girl with waist-length caramel blonde hair, waved back enthusiastically, her brown eyes shining. "Oh, Kōchūkyū onii-san!" 4989 loved how she and the other platelets referred to others as siblings, how unafraid they were of neutrophils. "There was a wound around this tooth, but we already got it all fixed up," she told them happily.

"Good job," 2048 praised them with a warm smile.

"Yeah, and we don't have to spend days in a clot," 4989 noted, grinning relieved and clapped his friend on the shoulder, though feeling a bit bad for the trapped erythrocytes, hearing some of them groan, probably stuck in uncomfortable positions. "Good timing."

"Any germs?" the other neutrophil asked, throwing a critical glance at the healing wound. The mouth was home to numerous bacteria, which were part of the natural flora, but displaced they too could become a threat.

Platelet-leader however shook her head. "One or two, but an earlier patrol already took care of them."

4989 wouldn't have minded some action, besides as of yet he hadn't eaten much today, but if it meant everyone here was save, he certainly wasn't about to complain. "Well, guess we can keep going then."

Suddenly someone tugged at his pants and the fluffy haired neutrophil looked down to a small boy. "Onii-san, could I get a ride?" he asked innocently, with big puppy eyes; 4989 hoped that it looked at least half as convincing when he did it himself.

"Sure," 4989 replied happily, reaching down; it was impossible not to adore the platelets or refuse them. "And up!"

After her encounter with 2626, AC continued to finish her delivery, before heading back to the lungs to have the carbon dioxide exchanged again. About halfway back, not far from the superior vena cava, she encountered another friend, though this time she was seen first.

"AC 4293!" a voice shouted behind her.

The auburn haired erythrocyte turned around, keeping one hand on the cart so it wouldn't roll away and spotted a red blood cell with short brown hair. "Hi, AD. Long time, no see." It was true that it had been some days since their last encounter, likely thanks to deliveries to completely different parts of the body. All the more reason to appreciate this chance to catch up, and from the looks of it, he too was on his way back to the lungs. "How have you been?"

"Pretty good, work's been going smoothly," he told her, stopping by her side, parking his cart right next to hers. Good thing she always kept to the side of the road. "Even had a delivery to the brain during a REM- circle; you should have seen it."

"Damn, I wish I got send up there more often." And with all that had been going on recently, it hadn't exactly been on the top of her mind.

"Maybe you should go in your spare time. I know it's far, but it's honestly worth it."

FP 1564 had given her the same advice once. "So I've heard."

Then his expression suddenly grew stern, worrying the auburn haired erythrocyte. This was not a good sign. Had something happened after all? "Look there was something I've been meaning to ask, actually me and CT."

Somewhere in the back of her mind, alarm bells were going off like a receptor in the presence of antigens. "What about?"

"Are you really spending time with a neutrophil?"

AC froze. They knew? They must have seen her along with 4989 at least at one point, which given how much they'd been hanging out recently wasn't entirely surprising. Still, she'd hoped to avoid exactly this confrontation; she had wanted to be the one to address the matter, though admittedly she had postponed it for some time now. Too long apparently. "I'm guessing you're not too happy about that," she carefully noted.

It was the look of disappointment that probably hurt most, and he had every right to be. She shouldn't have kept such a secret from her friends, people who were very much her siblings like FP had been. "Of course not." AD confirmed. "He could hurt you or worse."

AC's eyes widened. "He wouldn't do that," she protested.

"You were already infected with a parasite; what if next time, which I hope will never happen, he sides with the NK cell." Her friend pointed out. "Maybe he's only keeping an eye on you in case there are aftereffects."

"You make it sound like he's just waiting for the excuse to slice my throat." The suggestion utterly appalled her, plus it was absolutely absurd. Anyone who knew the fluffy haired neutrophil would know that, but that was the issue wasn't it? AD clearly didn't.

"Well, maybe he is."

"What?" This suddenly seemed like a bad joke.

Apparently the brown haired erythrocyte noticed that he wasn't exactly getting through to her. "I'm just worried that's all," he explained, placing a hand on her shoulder. "They are remorseless killers, the whole lot of them."

AC felt her initial shock getting replaced with annoyance. It wasn't the first time AD expressed his low opinion on immune cell, but this time it truly irked her. She jerked her shoulder away from under his hand. "How would you know? All you do is to slight them, without ever having talked to one of them."

He seemed stunned for a moment, before he furrowed his brow. "I don't need to. We can all see on a daily basis what they are all about."

"Yeah, when they are risking their lives to save ours, fighting those monsters." The battle against the E. coli was still pretty clear in her mind. "Has it ever crossed your mind that they might be different, whenever they are not in battle? That they are just cells like you and me?"

Now AD looked actually shocked. "What has gotten into you? It's as bad as CT said."

So she had seen them together. "And what does she have to say?"

Her friend sighed, lifting his hands defensively. "Look, we both think it's too dangerous; it's only a matter of time before something terrible will happen. So please, just stay away from him, from all leucocytes for your own good."

"No." That was not an option.

"AC, please be reasonable," AD pleaded somewhat desperately. "Look at it this way; there are only two ways this is going to end. Either something horrible will happen to you or he'll get killed in battle anyway. Neutrophils are not exactly known to enjoy long lives."

He wasn't wrong about the latter, but AC refused to let that affect their relationship. "By that logic we shouldn't be friends either, no cell should have friends. Any one of us could suddenly die one day. I was there when FP was taken from us, remember? But I don't regret having been his friend, his little sister; I'm glad for what time we actually did have." And it wouldn't be any different with 4989.

"You can't possible treat a neutrophil like FP; it's not the same." He sounded almost offended at the very notion, which only served to anger her further.

"U-4989 is my friend; he saved me, helped me when I was at my lowest point…"

And then AD interrupted her. "Are you sure you're not just replacing FP?"

It was like a slap in the face. "How dare you!" She hissed, hurt by his suggestion. "I'm not replacing anyone! How can you even suggest that?!"

"Because you've changed, because you've been keeping things from us," AD 5022 snapped back, angry now as well.

"Well, how could I tell you, if this is your reaction?" Sadness and disappointment dulled the rush of anger that had gone to her head. "I'd wanted to tell you, really I did, but I just didn't know how, how I could make you understand."

"And what if you're wrong?" He pointed out. "You're talking about a completely different cell type; they are literally designed to kill, you can't compare them to us."

"That's ridiculous!"

"Come on; they are separated from us from the start, even though we all grow up in the same bone marrow. Don't you think that is for a reason?" he added frustrated.

"And if I think it's wrong?" she told him, feeling that spark of fury again. "I've been around both red and white blood cells now and you know what? Turns out the neutrophils are a lot friendlier and less prejudiced than many of you guys are."

"AC…," AD began, but this time she interrupted.

"No, and you know what?" Angrily she pulled at her collar, exposing her neck. "If I ever do become infected and a threat to this body, I'll show them right where to strike!"

His eyes widened in horror, as she grabbed her cart and stormed off. "AC!" But she didn't turn around. She just had to get away; she couldn't continue to fight with him. AC bit her lower lip, her vision blurry for a moment.

Fearing he might follow her, the auburn haired erythrocyte decided to take a detour to the vena cava, not wanting to encounter AD 5022 again. The things he'd said….

AC however was not given time to agonize over the argument and its consequences, since she found herself walking past an enormous tree, one of many all across the body and she was yet again addressed by another cell. "Miss Red Blood Cell," a friendly voice greeted her. "Do you have a moment?"

The auburn haired erythrocyte turned around and saw none other than the resident Dendritic Cell, a kind smile on his lips, his expression completely serene. "...sure," AC replied hesitantly, not wanting to be rude, yet wondering what he could possible want from her. Their task was to communicate and relay information to other members of the immune system to help organize a response, which has nothing to do with erythrocytes.

In any case, he was delighted by her acceptance of the invitation. "Wonderful. Please come in." The green-clad cell gestured towards the opened door of his home, apparently wanting her to go first.

AC parked her cart next to the trunk, and entered the dimly lit interior of what she could only describe as a tree house. Everything here was made of wood, with the exception of a few telephones, tableware and the infamous photo albums she'd geard so much about, which stood in neatly ordered rows in numerous shelves along the walls. A latter was leading further up into the tree, and she had a feeling that even more cytokines were hidden there.

Dendritic Cell followed her in and closed the door behind him. "Have a seat," he told her as he crossed the room, nodding at the table close to one of the circular windows. As soon as she sat, he joined her, a small tray in hands. "Would you like some tea? Maybe a biscuit?"

While still confused by everything, she nonetheless appreciated the offer; she really could use something sweet right now. "Oh, thank you." AC took one of the biscuits, while he arranged the teacups, clearly in no rush. When he poured them tea, she couldn't wait any longer. "So, how can I help?"

Dendritic Cell sat down opposite to her and looked at her with a friendly, yet curious expression. "Well, as you know I'm somewhat of an observer, and of course I couldn't help but notice your friendship with U-4989."

"Oh," the erythrocyte muttered weakly. Please, not him too.

But he was still smiling. "Yes, I've seen something similar before with U-1146 and AE 3803, but was still surprised." He reached for something beneath the table. "Not that I'm disapproving, if you are wondering." With a fluid motion he produced one of his photo albums, skimming through it quickly, before handing it to her. "As a matter of fact I think the cytokines will be even more effective, when it comes to your friend."

AC wasn't sure what he mean by that, but the question that was on her lips was swiftly forgotten, when she saw the photos. "They're all of us!" Every single photograph on the two pages before her had been taken in the last few weeks, every single one showing her and 4989.

As the erythrocyte viewed the images, Dendritic Cell continued. "All immune cells fight for this body with all they have, but I like to think that additionally having something, or someone, specifically to fight for might provide even greater determination and ferocity."

"That still doesn't explain why you wanted to see me," AC noted, looking up again.

The green-clad cell sighed. "Well, I couldn't help but overhear you talking with your friend AD 5022."

She couldn't help but flinch. "I suppose nothing that happens in this body escapes your notice."

"Little I would say," he admitted, before tilting his head a little to the side. "What he said upset you greatly, did it not?"

"Of course it did," she all but exclaimed with a tight chest. "He was always fearful of immune cells, but that he would insult my friend like that, and simply disregard everything I had to say. I thought he would at least listen to me, but he almost acted as if I was delusional."

"He certainly is struggling with these new developments."

Self-doubt snuck into her thoughts and voice. "Have I truly changed that much?" she asked quietly, hands clutching the album.

"Actually you haven't changed at all." Dendritic Cell replied, taking a sip of tea. "You are still the same, as are your friends, but what has changed is your perception of leucocytes, and so now your views on this specific issue clash. You have lost those fears and prejudices."

"But how have I never noticed they hated immune cells that much? I mean I always knew they disliked and feared them, but…hate?" That it ran that deep and was that strong.

The green-clad cell refilled his cup. "I suppose it never was something you truly discussed before. You all did your job, never had anything to do with our body's protectors…until the parasite."

AC's eyes wandered to the bracelet 4989 had given her and back to the photos. "Do you think they could be swayed?" She asked, though she didn't have much hope. "That I could convince them to at the very least give 4989 and his friends a chance?"

"Frankly I'm not sure."

"Then what?" She felt so frustrated, helpless. "I don't want to choose between my friends." Sure she was angry at AD, but they went way back; she wasn't willing to give up so easily on their friendship.

Dendritic Cell shook his head, putting his cup down. "Of course not, but it might come to that. Sometimes people drift apart, for myriads of reasons beyond our control."

She sighed. "That's not exactly comforting."

He gave her a sympathetic smile. "No, I admit it's not, still you might want to prepare yourself for just that eventuality." She already dreaded it, but the immune cell hadn't finished yet. "Whatever path you choose in the end, if it comes to that, just remember that there is no right answer. Though may I say that I believe you have gained a wonderful friend." From his jacket he pulled a handful of photographs and handed them to her, winking to her surprise.

Confused AC took them, but then her eyes widened. "What? You were there?" Her cheeks flushed immediately.

Dendritic Cell chuckled and smiled. "I get around."

Not long ago the sprinklers at the intestine had leaked alcohol into the bloodstream. Having unfortunately been there just when it started, AC had quickly found herself drenched, yet continued to work. After managing to finish her delivery however the alcohol had truly taken affect, forcing her to lay down and rest. That was until 4989 had found her, and brought her to the liver. She had fallen asleep on the way, her friend having carried her, and when she had eventually woken up, tired but completely sober, he'd still been there, using his break to make sure she was recovering. But she hadn't known that Dendritic Cell had taken pictures.

Her eyes lingered on the first photo, showing the moment 4989 had found her.

.

"Wakey wakey."

"Hmm?" AC blinked, her eyes opening only slowly as she woke from slumber. "Hachikyu-kun?"

4989 smiled apologetically, kneeling next to the bench she had lain down on. "Hi; sorry to wake you, but I couldn't help but notice that you're soaked," he told her quietly, nodding at her wet clothes once. "Got hit by the sprinklers earlier, huh?" Her jacket was all but clinging to her membrane.

With one hand she rubbed her cheek, still not entirely awake. "Had picked up some nutrients, when it started," she began to explain. "It was okay at first; with all those widened blood vessels I finished the delivery really fast, but like right after…I just suddenly felt so tired."

"How about we get you to the liver?" the fluffy haired neutrophil suggested; she knew that she really needed some enzymes that would break down the alcohol, the kind only hepatocytes provided.

Still, his suggestion wasn't met with much enthusiasm. "Five more minutes," AC pleaded, closing her eyes almost completely, pulling her knees closer to her body. It would be such a long way.

Through slits she saw 4989 smiling mischievously. "I could tickle you," he chirped.

"Don't you dare," she merely muttered, but otherwise made no move.

Apparently he didn't have the heart to tease her like that, not in her state, as he opted for a different solution. As carefully as possible he picked her up from the bench, one arm around her back, the other under her knees.

Once again AC opened her eyes, momentarily confused by his unsuspected action. "What?"

"You can keep sleeping," he simply assured her, even as she felt herself drift back into slumber. "We'll be in the liver before you know it."

"…'kay," she managed to yawn as her eyes shut, her head falling against his chest, sound asleep within moments.

.

Dendritic Cell's voice tore her from her memories. "As I've implied, I believe these pictures will be of great value, when I have to activate my fellow immune cells again."

She barely listened as she went through the other photos, stopping at one in particular. "I don't remember this one. It's inside the hepatocyte establishment he took me to, but..."

He looked and nodded. "I believe he woke you so you could drink the enzyme," Dendritic Cell recalled, which explained why 4989 was holding her, helping her sit up, her body leaned against his for support. "You probably don't remember because you were completely inebriated at that point." His smile returned. "But he was very gentle with you."

Warmth was rising in her chest and to her cheeks. If only she'd had this photo earlier, when arguing with AD. Eventually AC looked up meeting Dendritic Cell's curious gaze. "You are a slyer cell than I gave you credit for, Jujō Saibō-san, if not a subtle one."

The green-clad cell chuckled again. "I seem rather bias don't I?" he noted, but then looked at her thoughtfully. "Well, I've spent a lot of time observing other cells, their interactions and I like to think that I've gained a certain…intuition for what others sometimes need to see or hear. If you believe I'm pushing you one way, please, take a look at those pictures again, but this time, take a good look at yourself, literally."

AC frowned, not sure what he meant, but did as he asked. She checked every photograph carefully, finding nothing unusual or special about them, though seeing herself in an intoxicated state made her feel a little bashful. Judging from 4989's expressions however, he thankfully hadn't been bothered; in fact on most images he looked amused or caring, sometimes both. She too smiled, on every single picture actually, even in her sleep…she just looked happy, content.

When she glanced up, not sure if she'd found what she'd been meant to, Dendritic Cell gave her another warm smile. "Whatever you decide to do in the end, whatever happens in the future between you and any of your friends, may I just advise you go with what feels right to you, regardless of reasons and arguments. You have to be happy with it."

After finishing her tea, AC finally made it to the lungs after all, thankfully not running into someone on her way there yet again. It gave her some much needed time to think about everything, even in the tightly packed heart chamber, though it wasn't easy to ignore that elbow in her side at one point.

Still contemplating she exchanged her carbon dioxide for a new batch of oxygen, eventually deciding that she wasn't really getting anyway and probably should get a decent meal before going all the way down to the shank for the next delivery. The biscuits had not exactly been filling.

Like most days she went to one of the many vendors by the side of the road back to the heart, getting herself some daifuku, before searching for an empty bench. It took her some time to find one, as numerous other red blood cells evidently had had the same idea too.

Eventually however the auburn haired erythrocyte did find a nice place away from the main road in the shadow of a tree, and feeling rather exhausted, all but sank down on the bench. She placed the bag containing her lunch beside her, before running both hands over her face, fingers massaging her temples and the area just beneath her eyes. When she lowered her hands again, there was suddenly a cup of tea dangling in front of her face, by the scent her favourite kind, jasmine. Surprised AC leaned her head back and looked up into 4989's brightly grinning face.

"Hi there."

…

As soon as AC lifted her face, he knew something was wrong, she wasn't just tired. "You seem troubled," 4989 noted worriedly, his smile fading. "Everything alright?"

The erythrocyte briefly bit her lower lip. "It's just my friends…."

He placed both their cups on the bench, before stepping around it. "Argument?"

"You could say that." He was about to sit down, when AC rose, standing now directly in front of him, taking a deep breath. "They are not too happy with us being friends."

"Oh." He lowered his head and pulled at his cap, guiltily hiding his face from her. "I'm sorry."

"What?"

"It's my fault," he claimed distressed. "I never wanted to drive a wedge between you and your friends. You guys have known each other since childhood and now I'm just barging in…" He should have known something like this would happen, especially considering her friends' reaction to him even after he'd saved CT 2980.

But AC suddenly grasped one of his hands, his head jolting up again. "No, no, no; it's not like that!" she quickly assured him, giving him a keen look. "You did nothing wrong."

"You can't deny that it's kinda about me," he pointed out.

She frowned. "Do you think I'm angry with you?"

4989 hesitated, feeling he could only answer wrongly. "Well,…maybe?" He did make life more complicated for her.

AC however only shook her head. "We may have only become friends rather recently, but you're just as dear to me. I don't favour anyone because of the duration of our friendship or something like that. And right now it's my other friends who frustrate me, not you."

"How so?" It sounded like there had been more to the argument than a simple case of erythrocytes being afraid of leucocytes.

Gently she squeezed his hand. "Well, you made the effort to approach and comfort an erythrocyte, who was irrationally afraid of the very cell who saved her, helped her see what an idiot she was." The smile she gave him made his all his mitochondria skip a beat, before her next words made it falter again. "Meanwhile my other friends won't even consider the possibility that immune cells can be anything but killers, and refuse to listen to anything I have to say about it. They even think that I'm just using you as a replacement for FP, or that you're sticking around to make sure I'm not defective after the parasite-attack. So no; I don't blame you for anything."

Replacement? The idea made his lysosome twist uncomfortably, though he couldn't believe that. AC wouldn't, he wasn't…he only needed to remember that one time she'd been drunk; sure she' been intoxicated, extremely tired, but also so very sweet and uninhibited. He just hadn't told her what she'd said to him in that state, not wanting her to feel embarrassed.

4989 looked to her hand, still clasping his. "So,…what now?"

AC hesitated. "I don't know, frankly I'm stumped," she confessed and shrugged. "Maybe one day I can try to address the subject again, perhaps with CT first, now that I have soured things with AD. But in any case I don't want this to change anything between us, okay?" And she squeezed his hand yet again.

Gratefully he smiled at her. "Right."

She too smiled again, but there was something else, something that kept her from being at peace. The fluffy haired neutrophil wanted to ask what it was, when AC spoke, sounding surprisingly nervous. "4989; can I asked you something?"

"Of course, shoot." Anything to ease her mind.

She inhaled deeply, only now letting go of his hand again, which didn't exactly reassure him. Had she kept the worst for last? "During the argument something else came up, and I couldn't quite shake the thought," she slowly began, eyes lingering on the bracelet he'd made for her. "Just hypothetically, should ever something happen to me…should I actually ever become harmful to the body…"

"What are you saying?"

AC gulped, her entire body language betraying just how tense she was. "Well, it's your job to keep the world safe, and I don't want to hurt those I care for. But if I…as unlikely as it is, do get infected by something again, become a threat myself, I harm this body and everyone in this world." The auburn haired erythrocyte lifted her head, meeting his gaze. "So, would you...take care of me?" and touched the hilt of one of his knives.

If he could have turned any paler he would have in that moment. Was she really asking him to…his body felt cold at that very thought, almost sick and he needed a moment to find his voice again. "Can I…can I still try to save you first?" 4989 asked her timidly, a flicker of hope in his pleading look.

For a moment she just blinked, perhaps surprised by his response. His cheeks grew warmer the longer she stared, making him start to wonder whether he'd said the right thing, when her lips finally curved into a soft smile. Then AC reached up, wrapping her arms around his neck for a tight hug. Before he knew what was happening, she pressed her lips against the corner of his mouth for a peck. "Yes." She whispered and squeezed him. "Thank you."

"You're welcome." He mumbled somewhat flabbergasted, though not quite sure why she thanked him; still, his cheeks were certainly all but glowing now. When she detached herself, all too soon, 4989 pulled down his cap again, hoping to hide his pink cheeks, though given the way she smiled he hadn't been fast enough.

Of course he would always try to save her.

The neutrophil could still feel where she'd given him that peck, not quite sure how to react to it. Should he acknowledge it? Act like it didn't happen? Suddenly he wished he could asked 1146 or AE 3803; surely they had been in a similar situation.

It was however eventually resolved after a few awkward moments, when his receptor suddenly went off, reacting to the presence of an antigen. Or maybe it had panicked and wanted to get out. AC actually jumped in surprise, while 4989's eyes widened, an electric shock-like sensation rushing through his body, as if he was suddenly experiencing an adrenaline rush.

"Go get them."

For a moment his expression softened, when he heard her speak, and he gave AC a quick smile. "Don't get into trouble while I'm gone."

She chuckled a little; he adored that sound. "Oh, don't worry; I'm sure AE 3803 and U-1146 are keeping it well occupied."

"Could be," he laughed, suddenly feeling so much lighter upon hearing her jest. "I'll be back."

She just kept smiling. "Counting on it."

And with that 4989 dashed off, back into the bloodstream, eyes peeled for any sign of a pathogen. Erythrocytes immediately started to jump out of his way, as he headed towards the heart, the still ringing receptor telling him that he going the right direction.

What had managed to get this far into the body? Sure there were a lot of new band cells around, but that something had found its way to the heart? That was troublesome.

As he kept running 4989 heard another receptor to his right and soon spotted U-2048. He wasn't surprised to see his friend, after all they had finished their patrol mere minutes before his encounter with AC.

"Seen it yet!" 2048 shouted across the heads of several red blood cells about to enter the left atrium.

"No!"

"Hey guys!" Both neutrophils turned their heads, and saw U-2626 catching up with them. "1146 called in, said he was pursuing something into the heart!"

"Of course he's the first on the scene," 4989 couldn't help but remark. It looked like AC had been right, but then again it was no secret that 1146 was some sort of trouble-magnet.

Together the three entered the atrium, pushing past the red blood cells around them, which now had some trouble making room, some even flinching when they made contact with the immune cells. This time however 4989 had an easier time ignoring it. His mind was too focused on finding the invader.

Instead he found another white cap in the crowd ahead, and it moved rather swiftly. Seconds later he got a glance at the face. "U-1146! Where's the antigen?!" the fluffy haired neutrophil shouted.

"Up there!" his friend replied, lifting an arm to point towards the ceiling.

And there it was. The ceiling and roof were supported by numerous wooden pillars and beams, creating something of an open framework. On one of said beams sat what looked like a Streptococcus pyogenes, but instead of pink, its cell wall was orange with green accents and it had clawed hands rather than blades. And it carried an unconscious platelet under one of its arms.

Streptococcus sanguinis

A common resident in the human mouth, this bacterium can be found in dental plaque, helping to keep others like Strepococcus mutans at bay, an important causer of cavities. After getting into the blood stream however, following oral surgery for example, they can colonize the heart valves, causing endocarditis using platelets and fibrin to attach to the tissue and protect themselves from phagocytosis.

4989 recognized the girl from earlier today at the mouth, the leader of the little group of constructors, the sight only serving to fuel his bloodlust.

"Quick; get up the wall!" 2048 shouted, 1146 already pulling himself up onto a beam.

Realising its worsening odds, the bacterium deftly climbed higher, reaching the ceiling. Its claws cut through the tissue, creating a large enough hole for it to get through and onto the roof itself. The neutrophils followed, 1146 being the first to make it given his head start.

The other three were not far behind however, reaching to top mere seconds later, 4989 finding himself briefly blinded by the bright light, after the dimly lit interior of the heart.

His eyes quickly adjusted and he looked across the giant temple-complex, its vast gable roofs just steep enough so one could still run across most of them. The bacterium was having no difficulty traversing the one they were on, its claws finding purchase on the smooth tiles, even as it moved along the edge. Only on second look did the fluffy haired neutrophil saw that it was actually using bits of fibrin, seeing the pink substance at the sole of its feet.

The four neutrophils pursued, not as quickly as they would have liked, having to make sure that they kept their balance on the tilted surface. Still, they managed to gain on the bacterium, as the fibrin, while providing purchase, was only reluctant to detach again, making the escape rather strenuous on the germ.

"It's headed towards the aortic valve!" 2048 suddenly realised, looking to the building ahead.

Hearing the shout the Streptococcus turned its head, seeing how close the immune cells were; if it hadn't been holding a hostage, there would already be several knifes sticking in its back. However now it was getting desperate.

It suddenly threw the platelet away, flinging her off the roof. "NO!" Without a moment of hesitation 1146 jumped, actually grasping her, pulling the girl close to his chest.

"1146!"

The three slowed down, watching their friend fall. Back first he landed in a tree, a few branches breaking upon impact, while he covered the platelet with his arms, but it broke his fall. "We're fine! Get the germ!" They heard him shout from below, freeing himself from among the broken tree limbs and twigs.

"Roger!" 2626 replied and they picked up the pace again.

The Streptococcus was now panicking and tossed something else at them, a bluish orb. 2048, closest to the germ, lifted his right arm to shield his face, the orb shattering on impact. 4989 heard his friend scream, steam rising from his arm, accompanied by a hissing sound. Nonetheless the straight haired neutrophil pulled something from one of his pockets, and threw a NET at the invader, even as he stumbled to his knees.

The net didn't manage to capture the bacterium completely, but it did wrap itself around its leg, causing it to fall face first onto the roof. 4989 rushed past his friend and drew his weapon. "Die, germ bastard!" and his blade cut across the back, finishing it off.

Catching his breath the fluffy haired neutrophil turned around, seeing that his crouching friend was cradling his injured arm, the fabric of his uniform eaten away by the corrosive substance the bacterium had used.

"Well, that was some hunt," 2048 noted with a pained smile.

"How's your arm?" 2626 asked as he kneeled down next to him.

"Burns," 2048 merely replied, removing what was left of the sleeve to reveal a severely blistered membrane. "Damn that hydrogen peroxide."

"Good thing it only hit you there," 2626 pointed out, examining the injury. He was right; they had all heard stories of other neutrophils, who had been so injured that they had resorted to committing suicidal NETosis, hoping to take the germs with them. "You better get that looked at though."

"Guess that means I won't be going on patrols for a while," 2048 said, sounding not too happy, carefully testing the mobility of his arm only to flinch.

Glad that his friend was doing alright, or at least wasn't in any immediate danger, 4989 was about to put his knife away, when the bloodied blade caught his eye. With his bloodlust gone, AC's question was suddenly ringing in his mind. Could he…take care of her? Could he do what he had just done to this pathogen to her? His organelles twisted painfully, his hand clutching his weapon tightly. That the bright red cytoplasm dripping from the knife could one day be hers. No,…even though she'd asked him to, he couldn't, he…

"Something wrong, 4989?"

2626's voice brought him back to reality. "What?" Putting on what he hoped was his usual smile, 4989 looked up to his friends; he didn't feel like talking about it, not right now, not here. "No, I'm fine; just lost in thought for a bit there."

Fortunately they seemed to accept this without further questions and turned their attention to the dead germ, 2626 getting out his enzyme spray; with the net covering half of it, eating it would be a bit troublesome. Frankly 4989 wasn't exactly feeling hungry anyway. Briefly his eyes wandered back to the knife. She was right; it was his duty to protect this body, even if that meant eliminating other cells. But her? He sometimes felt guilty just for accidently spooking her whenever he showed up using the ventilation and sewer shafts, so how could he even harm a single hair on her head, much less…kill her?

There really only was one option: keep her safe.

Chapter Text

Bone Marrow
Part 1

The water at the wash station seemed even colder today than usual, if that was even possible. 4989 membrane started to feel numb, as he sat there under the shower head, but he still had his hair and cap to rinse out. He was currently alone, 2626 having taken 2048 to get some medical attention for his injured arm, though they weren't too concerned, given that the wound was mostly superficial.

And so the fluffy haired neutrophil's thoughts wandered to something else that had been on his mind, and he wondered whether he should seek out AC again as soon as he was done here. Still troubled, he found himself just wanting to talk with her, perhaps ask her why and how she'd come up with her bewildering request in the first place. Just thinking about doing what she'd asked him to sent shivers down his spine.

By the time he'd almost finished, 1146 came in, uninjured and without a drop of cytoplasm on him. Instead his uniform had green and brown spots all over it, thanks to the tree that had cushioned his fall, which needed to be removed all the same.

He looked around. "Where are the others?"

"Gone to have 2048's arm taken care of," 4989 told him as he wrung out his cap, the drops of water still reddish.

"Is he going to be alright?" 1146 had only gotten a glimpse at the wound, as he'd been occupied with the hostage, and making sure she got some medical attention.

"Yeah; it didn't seem too severe, just the membrane." He indicated the inured area on his own lower arm. "Painful, but it's thankfully nothing life-threatening. How's the platelet?"

"Awake and well. She was a bit confused though; apparently she got knocked out quickly, before she even realised there was a germ, but otherwise she's unharmed."

The fluffy haired neutrophil smiled relieved. "Glad to hear. 2048 and I just saw her this morning," he sighed, unable to ignore a sense of guilt. "Makes me wonder, if we perhaps could have found this bacterium earlier."

"For all we know it got in after you left the area. According to the platelet there had been numerous minor wounds around the teeth today," his friend assured him to ease 4989's mind as he took his jacket off, the back bright green, and sat down on a stool. "The important thing is the bacterium was dealt with, and no one died."

"True."

4989 finished up and towelled his hair down, making it look even messier than it usually did, but at least he didn't feel quite as cold anymore. A nice, warm tea seemed a good idea; the last he'd left with AC…

His hands slowed to a near standstill. That hadn't been too long ago; maybe she was still there or was at the heart.

"Are you alright?" 1146's voice suddenly snapped him out of his thoughts. "You seem…preoccupied."

The fluffy haired neutrophil opened his mouth, yet hesitated. Still, now that he thought about it, who could better understand his dilemma? Slowly he walked over to 1146, who was cleaning his jacket. "It's just something that came up when I talked with AC today; haven't been able to get it off my mind," he confessed, taking the towel off his head, clutching it in his hand instead.

His friend frowned concerned. "Did something happen between you two?"

"No, no, not between us. Not really." It hadn't been an argument after all. "Probably best if I told you the whole thing."

1146 didn't interrupt once as the other neutrophil explained what had happened at the pulmonary vein, what had occurred between AC and her friend, her decision not to compromise her friendship with 4989, as well as her request at the end.

There was a moment of silence after the fluffy haired neutrophil had finished. 1146 looked pensive. "Take care of…," he mumbled to himself.

"How can she ask me something like that?" 4989 all but exclaimed troubled; he never ever wanted to be in that position. But if she ever became harmful to the body, what choice would he have?

Suddenly 1146 stood beside him, placing a hand on his shoulder. "She knows what we must do, and is very well aware that any cell can get compromised, even though she can't get infected by viruses and others of their ilk," but then he smiled encouragingly. "In a way it's actually touching."

Now 4989 was confused. "How?"

"Because it means she trusts you with her life, above anyone else. She trusts your judgment, no matter what happens to her. And I think with your answer you've already rewarded her faith in you," 1146 continued. "Her friends think we kill as soon as even suspect a threat, and you proved them wrong, when you showed that you'd prefer to save her. I think that's why she thanked you."

He hadn't considered. He'd been so confounded by her request, but 1146 was probably right. She hadn't asked this after another pathogen attack, instead she'd made her request right after a confrontation with her friend. Trust. "But still, one day I might…not be able to save her. One day I might have to keep my word. That's what scares me, and I'm not sure if I can do it," he noted distressed, not able to quite shake that thought.

"Hm."

"I mean could you? With AE…?" Quickly 4989 stopped himself, when he realised what he was asking his friend; hadn't Memory T Cell indicated something very similar as well once? "Sorry, I didn't mean to…"

But his friend shook his head. "No, it's alright," he assured the fluffy haired neutrophil. "I have mused on this very question before. Frankly, I'm not sure what I would do, and there are too many variables to consider. So I've decided not to trouble myself too much with these thoughts."

4989 gaped; that sounded so unlike his friend.

Apparently recognizing his confusion 1146 continued. "Erythrocytes can't get infected by viruses, thanks to them lacking a nucleus and bacteria usually only see them as prey, a method of transport at best. But they are never taken over, there is always a chance for us to interfere, to save them. And that's what I intent to do."

Okay, that did sound a lot more like him. That unshakable determination; 4989 had always admired that. "I hope you're right," the other neutrophil replied.

"And remember, it is the macrophages' job to take care of them at the end of their lives, not ours. So all things considered, I encourage you to think of her request as a show of trust first and foremost." He gave 4989 a somewhat quizzical look. "Does she know?"

"Know what?"

"That you like her," 1146 simply stated. "You're usually more positive. That you are this troubled and worried."

"Like…?" And his eyes widened, when he realised what his friend was implying. "No, it's not like that," the fluffy haired neutrophil hastily claimed, wildly waving his hands in denial, only to see 1146 frown.

"You shouldn't be so quick to deny, U-4989," another voice suddenly chimed in.

Both neutrophils looked to the entrance, seeing a cell dressed in green enter the wash station. "Dendritic Cell? What are you doing here?" 4989 asked, astonished to see him, if not exactly pleased.

"I actually came looking for you," the other immune cell merrily replied, a warm smile on his lips, as he joined the two. "You see, I've met your friend AC 4293 earlier today, and she was quite upset."

That she hadn't mention. Then again there had been a lot on her mind, and their conversation had been cut short by the alarm. "You talked to her too?"

Dendritic Cell nodded. "We had a little conversation," he vaguely stated. "In any case, she could really use someone to support her, and I can think of no better person than you," and he pulled something from out of his jacket.

"What is this?" Frowning 4989 regarded the small envelope the green-clad cell was now holding in his hand.

"Something that might help dispel your doubts," Dendritic Cell merely replied, and handed it to 4989. Hesitantly the fluffy haired neutrophil took it, immediately feeling the edges of what he assumed were photos inside. Meanwhile the photographer himself bowed his head and took his leave. "Good day, until the next activation," he told them and left again, as suddenly as he had shown up. Odd, even for him.

"Goodbye. Photos?" 1146 asked, turning to his friend.

"I think so." He turned the envelope around, but there wasn't anything written on it that hinted at the content.

"Don't you want to open it?"

4989 gave the other neutrophil a wry smile. "These are Dendritic Cell's photos; so no, I'm not so keen."

His friend chuckled. "Well, he did say they would dispel your doubts, so perhaps a peek wouldn't hurt." He put his still damp jacket back on, and fixed up his uniform. "Anyway, I promised AE I'd meet her, so I'll see you later."

"Yeah, see ya," the fluffy haired neutrophil responded and waved 1146 goodbye.

As soon as his friend had left, his eyes turned back to the envelope. Of course he was curious, but remembering what pictures Dendritic Cell usually distributed made him shiver. But then again, he wouldn't risk activating him just for fun. There was a deliberateness to everything that green-clad cell did, maybe even mischievousness, but never malevolence.

4989 took a deep breath and opened the envelope.

It contained a handful of pictures, and it only took him a moment to realise, that they had all been taken on the same day, the last time the body had dealt with alcohol. That day he'd found AC asleep and tipsy, not quite able to find her way to the liver, and so he'd carried her there, stayed with her until she'd become sober again, something that had surprised a few cells.

.

The liver was a massive organ, a city within a city, home to the hepatocytes, whose tasks were as diverse as they were vital. In labs and workshops they synthesised proteins or broke down substances the body didn't need or were toxic, and stored what might be required at a later date, like some vitamins.

But today 4989 had gone to what could best be described as a mix between a bar and a spa, one of countless serving the erythrocytes passing through. Here the blood was cleaned of toxins, including alcohol.

Thus he had brought in the still sleeping AC, and given her into the care of to the hepatocytes working here, who had taken her into what he assumed was a bath. The sounds and scents certainly reminded him of the wash stations he frequented.

Meanwhile he was still standing in the lobby, talking to a third hepatocyte. "Thank you for bringing her here, Kōchūkyū-san," she told him with a gentle smile. "We'll take good care of her," she assured him.

Of that he had no doubt. Still. "Actually would you mind if I stuck around for a bit, make sure she's alright? You seem to be swamped with erythrocytes at the moment." Thousands had been affected, and even though every street here was lined with these establishments, they all seemed quite busy; he could hear the drunken singing of some red blood cells in the bar beyond one of the doors. His request unsurprisingly earned him a look of surprise, even confusion, and his cheeks grew warm. "She's a friend," he tried to explain a little awkwardly.

Thankfully her smile returned, the hepatocyte actually chuckled and nodded. "Of course, certainly." She gestured towards another doorway. "We keep the area in the back reserved for those who need to sleep it off or simply require a quiet place as they recover; you may take her there, and one of us will be around with the enzymes shortly."

Relieved and grateful he bowed head. "Thanks."

….

A little later another hepatocyte asked him to come into the bath where he found AC still asleep, but showered, now dressed in dry pants and a new black shirt. Other things were missing however, like gloves, jacket and beret, which the hepatocyte explained were currently drying and could be retrieved once AC was sober and ready to leave.

4989 carried her to the room he'd been shown earlier, finding that it contained several booths that could be veiled with a curtain, allowing for some privacy. The fluffy haired neutrophil very gently laid her down on the curved bench, before he closed the curtain and sat down beside her.

Not a minute later the hepatocyte he'd talked to earlier arrived with a small glass containing a watery substance, though it looked to be more viscous; the enzyme no doubt. She offered to bring him some tea, an offer he gratefully accepted.

As soon as she'd left again, he sat AC up, her head immediately falling back again his collarbone. Fearing she would fall or simply collapse, 4989 wrapped an arm around her, pulling her onto his lap to better support her, and gently shook her by the shoulder. "AC?"

"Hmm?" Her body swayed, but his hold kept her upright. "Where?" she managed to asked, her voice low, sounding so very tired.

"Liver; we're in a hepatocyte bar." She merely hummed at his exposition, her fingers idly brushing against the collar of his jacket, as she turned her head to look at him with barely opened eyes. It was strange to see her like this. "You're alright?"

He didn't get a verbal response, but she looked up to meet his eyes, a tranquil smile on her face.

"You're really drunk now, aren't you?" the neutrophil asked amused.

"Yep." AC chirped adorably, tapping the tip of his nose with one of her bare fingers and grinned amused, if tiredly.

"Figured." After having worn those alcohol soaked clothes for so long it wasn't exactly surprising. Carefully he picked up the small glass, holding it up so she could see. "Now; you've got to drink this."

She looked at it for a moment, as if trying to make sense of his words. "Okay." AC took the glass, her movements slow, and downed it without hesitation, only to immediately pull a face, shaking her head, as she put the glass back on the table.

"Doesn't taste so good?" he asked amused.

She stuck her tongue out like a little child, eyes closed. "Tangy."

4989 couldn't help but chuckle at her expression. "I'll get you something later; some buns, daifuku…" Some tea would probably also be nice to wash out the taste, maybe he could share his, once the hepatocyte returned.

"'d love that," AC mumbled, sounding more sleepy again, but still managed to smile softly at him. She reached up with one of her hands, and suddenly her fingers were brushing against his jawline. Her bare fingers. 4989 felt heat rising to his face. Both erythrocytes and neutrophils never took their gloves off while on duty, you never touched someone without them. This was more than a tap, this was rather intimate for cells…or it would have been, if AC wasn't drunk. And he was sure she wouldn't be doing this if she were sober. Still, the fluffy haired neutrophil didn't pull away, on the one hand having frozen up, but on the other finding himself actually kind of liking the contact, and not wanting to break it. "You're so amiable."

Her words unfroze him. "What?"

"Everyone thinks neutrophils are so scary and creepy, but you are such a sweet guy. You care so much for your friends and just wanna keep everyone safe." Her hand was now framing his face, but due to her state the touch was very light, and he was expecting her hand to slip off any moment. "And always up to something, always smiling, always tryin' to make others smile. You're so empathetic, so emotional."

4989 was certain he could feel his cheeks turning pink as she spoke. "I thought we agreed you were the softie," he teased her, trying to cover up his bashfulness.

She slowly stuck her tongue out, a finger poking his cheek. "No, you are." But then her expression softened again, lips curving into dreamy smile. "But I love that. Don't change, 'kay?"

His mitochondria leaped in his chest, a warm feeling spreading through his entire body. "Promise."

Her hands reached further up, and curious as to what she was up to 4989 didn't move. Her fingers continued to trace his face until they reached the hairline. AC grasped one of his curls, but merely seemed to feel, which confused him a little.

The soft smile on her lips widened. "Your hair really is as fluffy as it looks," she murmured happily.

Taken aback by the sudden change of topic, and what he assumed was a compliment, he felt a little flustered. "Ohm…thanks?"

Thankfully AC seemed satisfied with his reply, at least her smile remained, even as her eyes closed again and her hand slipped down, back into her lap. Mere seconds later she had drifted back into sleep, her head once more resting against his shoulder. But this time she looked very content. She looked happy.

.

Smiling to himself 4989 put the photos away into one of the many pockets on his uniform. That had been a rather strange day. AC had woken up some time later, still a little tired, but completely sober, not remembering anything from the moment she'd fallen asleep in his arms, as he'd carried her to the liver. He hadn't told her anything about their exchange while she'd been drunk, fearing to abash her, or make things awkward between them.

Still, he kinda liked thinking back to that day, to holding her, remembering what she'd said, how she'd snuggled up to him in her sleep.

Trust. 1146 was probably right; whether she was drunk or not, she really did trust him, and was comfortable around him. Even when she had awoken sober, she'd not been startled about finding him holding her, just a little disorientated at first, before thanking him for getting her to the liver.

4989 chest felt light and warm at these memories.

Was his friend right about that too? So far he'd seen AC as another friend, but after what 1146 had said, after looking at these pictures…maybe? Dispel you doubts. Frankly he still wasn't sure, and right now there was a lot on his mind. Besides, currently she was even more rattled due to what had happened between her and her friends. Last thing she needed was him being weird, well, more weird than usual. Even Dendritic Cell had asked him to be there for her. 4989 smiled again; that he could certainly do. He could sort those feelings out later.

Two days had passed since her argument with AD 5022, enough time for AC to collect herself again. Mostly. Of course they had argued before. They had grown up together, they were friends, things like that happened, but this was the first time it truly felt like there was now a rift between them, one she had no idea how to fix it. And despite how angry and hurt she'd been by AD's words, she still wanted to.

Storming off had probably not been the wisest thing she could have done, but there was nothing she could do about it now. Not until heads had cooled, hers included.

With that in mind, AC had decided to continue on as usual. Frankly she could talk to her friends all she wanted, but she had the suspicion that without actually talking with a neutrophil, they wouldn't understand her. Maybe she could ask 4989 to help her, though the thought of dragging him further into that mess made her feel a little uncomfortable.

Still, she could ask him, after all easing the fears of erythrocytes towards the immune-cell was one of his proclaimed goals. Maybe she wouldn't address it soon, she didn't quite feel ready for another confrontation, but it was an option, and she certainly would feel more confident with his support.

AC sighed and turned her attention back to the map in her hand. She had actually been deciding on a route for her next delivery, when someone calling out for another erythrocyte with the initials 'AD' had distracted her.

Looking back at the paper now, the auburn haired erythrocyte twisted her mouth, eyes narrowing. It wasn't the newest version, many roads had been closed and new ones had been opened since she'd gotten it, and so her map was covered with notes, crossed out streets and others added with a different coloured marker. Even some of those were already crossed out again.

Still, AC managed to find a viable path through the mess that should hopefully get her to her destination, when suddenly a hand was placed on her right shoulder and a familiar, cheery voice addressed her. "Hi there."

Warmth spreading through her chest, AC looked over her shoulder, seeing 4989 standing right behind her, that bright grin on his face, winking when their eyes met. "Hi; should have figured you'd find me here," she greeted him happily, returning the smile.

Removing his hand, 4989 instead placed his head on her shoulder to glance at her map, before looking at her with big, curious eyes. "So, where to today?"

"The red bone marrow," the erythrocyte told him, as she folded her map together. "Want to come along?"

"May I?" he asked innocently, making her chuckle.

"Like I'd ever say 'no'." There was no way she ever would.

Suddenly his arms were around her, head lifted from her shoulder, and with his hands on the handle of her cart he started to push. "Onwards then."

"Oh, you're not driving!" she laughed, rushing forth as she grabbed the handle as well, making him lose his grip.

With two swift steps 4989 caught up again, looking at her quizzically. "What? One dive into a shrub and I've lost all driving privileges?" he questioned, referring to his so far only driving lesson in another bone marrow.

"And a tree, and a lake," she teased, as they started to walk side by side towards the heart. "But yeah, that's how it works."

"Tough terms," he noted disappointedly, before a pleading look appeared in his eyes. "But I'm still allowed on as a passenger?"

"Once we're about to enter the aorta," AC promised him with another chuckle, but then her smile faded a little. "I've started to wonder where you were," the erythrocyte confessed. "Haven't seen you since your receptor went off and you ran into the heart. Did you get injured?"

Thankfully he shook his head. "No, I didn't get a scratch myself, though 2048 got a nasty burn on his arm, when the bacterium used its acid, and a platelet was taken hostage. Don't worry, she's fine and lively," the fluffy haired neutrophil added when seeing her concerned expression.

"Glad to hear. How's 2048 recovering?" 4989's friends were all such wonderful people, she'd hate it if anything terrible were to happen to any of them, and of course she knew what they meant to him.

"Membrane's still mending, says it itches, but he should be back in the field soon. We try to visit him as often as we can, so he doesn't get too bored." Abashed 4989 rubbed the back of his head. "Sorry I didn't find you earlier."

Quickly AC shook her head, placing a hand on his arm. "Hey, as long as you're not hurt it's fine." She could have sworn she saw the faintest touch of pink on his cheeks when she said that.

The two cells continued to talk all the way to the bone marrow, 4989 telling her in more detail what had happened at the heart, and AC caught him up on what she'd been doing these past two days. Apparently she'd encountered a new band cell, lost and too embarrassed to call his senpai for directions. Amused she told 4989 about how flabbergasted the very young neutrophil had been, when she'd offered her help, and given him directions.

The fluffy haired neutrophil meanwhile was absolutely delighted. This was exactly the kind of thing he wanted to achieve. When they had first met and talked she'd been so timid around him, uncomfortable even, and now she even approached other leucocytes without fear. If only he could get through to more erythrocytes.

Still, he was happy, not just because of her story, but because AC also seemed to be doing much better than last time he'd seen her. He wondered if there had been some new development between her and her childhood friends, but decided not to ask for now, not wanting to ruin her good mood. Besides, he was sure she would tell him on her own accord.

Eventually they reached their destination, one of the bones, which contained the blood cell creating red bone marrow. The architecture around them changed gradually, the road they had taken soon flanked by the distinct, maroon-coloured school buildings, but also lawns and play grounds. Children were everywhere, mostly erythroblasts, with girls wearing ankle-long dresses and boys in short, but all wearing berets with a pompom on top, representative of their nucleus.

There were also a few myelocytes around, but far fewer in number. Remembering his own childhood and training, 4989 figured that they were currently enjoying a break between lectures and combat training, watching a small group play tag with dummy-knives drawn, chasing each other across the lawn.

"Haven't been here in a long time," he mused aloud, feeling a little nostalgic now that he was back here.

"Bone marrow not usually part of your patrols?" AC asked curiously, looking over to the playing myelocytes now as well.

"It actually is, but this happens to be the bone marrow I grew up in, so it's nice to be back. Not that it has changed since I was last here." He turned to her, curiously tilting his head a little to the side. "How about you? Did you grow up here as well?"

But AC shook her head. "No, I was born in a different marrow, which actually is no longer producing," she explained.

Haematopoiesis

Blood cells are most produced in different regions/organs, depending on a person's age. Initially blood cells are created in the embryo's yolk sac, until liver, spleen and lymph nodes are developed enough to take over.

Eventually the red bone marrow however becomes the virtually sole producer of new blood cells. Initially there is red bone marrow in all bones of the body, in adults however blood cell production occurs in bones such as the pelvis, cranium, sternum, as well as the vertebrae and ribs. The red bone marrow in other bones gets replaced with yellow bone marrow with age.

"Funny to think we could have met long before working in the body." Who knew how things could have worked out, if had they first encountered each other as children.

"I don't know," she replied, regarding him with a thoughtful look. "I probably would have been afraid of you and the others, just like most erythroblasts."

His mitochondria sank at that. "Possibly," 4989 conceded somewhat crestfallen, knowing she was probably, and sadly, right. "Shame really, I mean here they are, playing side by side, yet there is no interacting." It was true that while despite there being dozens of children around, no one played with a cell of a different type, they didn't even seem to pay much attention to each other.

"I obviously can't speak for the myelocytes, but I can tell you we frankly just thought you guys were weird. We were probably a bit too afraid to even dare talk to you too. I mean we only ever interacted with adult white blood cells during training," the auburn haired erythrocyte explained. "A senior neutrophil would come over and 'teach' us how to run away from germs, by scaring us half to death, pretending to be one."

"Sounds fun," 4989 quipped, remembering his own teachers getting into character during his training, often while wearing a costume that had been patched far too many times already, making it look like a quilt with teeth.

AC however was quick to nudge him with her elbow. "Hey!"

"Kidding," he hastily claimed, still grinning though.

"Trust me; having a neutrophil hunt you down with a bloodthirsty look in his eyes, yelling about how he's gonna eat you, does make for an imprinting first impression." Unfortunately she had a point.

4989 sighed and looked around, eyes wandering back to the children playing together on the lawn. This time however he looked to the erythroblasts. "Kinda the opposite from what I'd like to achieve," he admitted as he watched them.

AC nodded. "Plus whenever we saw the myeolcytes, we saw them hunt each other with knives, mostly while proclaiming how they would be the best white blood cell ever and kill every germ."

"It's every boy's dream, you know," he said with a smile.

She chuckled at this. "Perhaps, but it did give the impression that killing was everything there was on your minds," AC noted, but then noticed that he was only half paying attention. "Something wrong?"

"Nah, I just realised again that I really have my work cut out for me," 4989 told her and suddenly stopped. "But maybe I've been thinking about this problem all wrong."

"What do you mean?"

"Well, I always thought of how I could improve the image mature erythrocytes have of us, but I alone just can't do that, might even be too late. But erythroblasts," he gestured towards the group closest to them, his voice rising as he continued excitedly. "Their views aren't set in stone, they are still figuring everything out." Why hadn't he thought of that before?

AC pondered his words for a moment, before she slowly began to nod. "It probably would help if erythroblasts knew how you guys are outside of battle, why you really fight as hard as you do," she admitted. "I mean, hardly anyone fears the macrophages and they are easily as passionate about killing germs as you guys are. Not to mention their work in the spleen."

"Are there visiting hours for erythroblast classes?" If neutrophils taught them on occasions, perhaps he could get in somehow as well.

She shrugged. "Not that I know of, but perhaps you could ask one of the macrophages."

"Worth a shot." He was actually getting excited. For so long he'd wondered what to do, and finally he had something like a tangible plan, something realisable. 4989 looked back to the children. "Oh."

"Huh?"

The fluffy haired neutrophil didn't answer AC, as he was already walking across the lawn towards the erythroblasts. One of the girls had fallen down, and was now holding her right knee, quietly sobbing. The others, about a half a dozen blasts, were gathered around her, but clearly didn't know what to do. One of them spotted 4989 and shrieked, more surprised than fearful, but still alerting the other children.

He could see they were nervous, and felt a little disappointed when they backed off a little, though he tried not to show it. At least it wasn't fear they displayed, it was more uncertainty, as if they weren't quite sure what to make of him. 4989 sat down next to the girl, who was still holding her knees, and perhaps due to her tear-filled eyes, hadn't noticed him yet.

"Hey, are you alright there?" he softly asked her, gaining her attention. The young child sobbed, but wiped away her tears with her small hands, brushing aside some of her light brown hair. She opened her mouth to say something, but gasped when she looked at him, realising that he was a neutrophil. Deciding to ignore her reaction, 4989 put on a smile and examined her wound. It wasn't anything serious, just a scrape, though it was leaking red cytoplasm and was likely quite painful. AC joined them, having left her cart behind on the road. "Do you have tissues with you?" 4989 questioned, wanting to clean the wound before applying a plaster to it.

"Sure." She briefly rummaged through her bag, and sat down on the lawn beside him. "Here."

Thanking her with a nod he took the tissue, turning back to the girl. "Don't worry; I'm not gonna hurt you," he assured her.

AC, having naturally noticed the child's uneasiness as well, gave the girl a reassuring smile. "It's alright, you can trust him," AC told her, and the girl slowly nodded.

"You know a white blood cell, big sis?" one of the boys suddenly piped up, as 4989 very carefully dabbed off the cytoplasm, cautious not to accidently inflict pain by brushing against the wound.

Meanwhile AC turned to the other kids. "Why, yes," she told them straightforward. "He's my friend."

He still loved it when she so openly, happily even, referred to him as her friend; it made his mitochondria skip a beat. Having finished cleaning the wound, 4989 pulled out a plaster from one of his pockets, as he carried a small packet of them around at all times, just in case. The scrape had already stopped leaking cytoplasm, but he didn't want it to reopen. "There you go," he told the girl as he applied the plaster, covering up half the knee.

"Thank you, Mr," the little erythroblast replied timidly.

"You're welcome."

"You're really a neutrophil?" the boy asked, looking more curious than afraid now.

Not a question he'd expected. "Yep; don't tell me you've never seen one before."

"Only once," the child admitted. "He taught us how to run from bacteria."

"He was really scary," the injured girl added, her cheeks turning red, as if she was ashamed.

4989 tilted his head, keeping on his smile. "Am I scary?"

The girl hesitated, taking a good look at him as it seemed, but then shook her head. That was a start.

Remembering what AC had told him just a few minutes ago, he continued. "I know it was probably terrifying, being hunted down by a shouting neutrophil, but all we want is to keep you guys save. One day you're gonna be out there in the blood vessels, and sooner or later you will come across a germ; being able to keep a clear head, even when you're scared, may one day save your lives. At least until we arrive on the scene and deal with it." He looked to the other kids. "But we don't want to hurt you; we here to protect you, all cells." He could only hope they would believe him.

"He saved me too, you know." Astonished 4989 stared at AC, who winked at him and turned to the children again. Did she want to tell them?

They seemed surprised as well, if likely for different reasons than him. "Really?"

"Yeah. You see that?" Lifting her right hand, AC pulled at the white bracelet he'd once given her, revealing the pale bite-mark the Plasmodium had left. She really was going to tell them, she didn't even mind the look of her scar anymore. When had that happened? "There was this nasty parasite that had gotten into the body, but it was also very sneaky. It disguise itself bracelet, and thinking it was a harmless piece of jewellery I was given one as a gift."

"How did you get rid of it?" another girl asked, leaning closer to examine the scar.

And so AC told them about the Plasmodium falciparum invasion. 4989 noticed that she made sure not to be too descriptive, which was probably for the best. The image of erythrocytes drained of their haemoglobin was not something for children.

Nonetheless the erythroblasts were soon hanging on AC's every word, and the neutrophil wondered if this was the first time they heard a story from the outside. They had lessons on how the body worked, on what their duties would be, but he doubted they learned of any events that were happening throughout the body. Well, in the case of the hypovolemic shock that was probably for the best. How had things been here during that catastrophe?

In any case, right now the children were invested, and 4989 couldn't help but be a little jealous, seeing how easily AC seemed to connect with them. They trusted her, called her 'big sister', even though they had just met her. How could he get there? But he was of course glad the erythroblasts became visibly more at ease, especially after AC told of his involvement in the whole thing. He really hadn't done all that much, but she managed to sell it, and he could almost feel the earlier tension disappearing as she told the story.

"You really saved, big sis?" the erythroblast he'd patched up asked brightly.

"Ohm yeah, kinda. I mean I helped," 4989 admitted flustered, and was actually rewarded with the first smile he'd seen on the girl's face.

Meanwhile his friend seemed rather amused by his awkwardness and continued on, placing a hand on his arm. "And then there was the time some weeks later he saved me again from a bunch of E. coli bacteria, which wanted to make me their meal."

4989 was certain that his cheeks had turned pink at this point, but at least the way the children acted now reminded him of the platelets. Could it really be that easy?

"But," another boy with black hair chimed in, yet quickly lowered his voice to whisper into AC's ear, if not quietly enough. "Don't immune cells kill other cells too?"

Gently she took the boy's hands, and her gaze was meeting his directly, as if to make sure he listened. "It is their job to kill any organism that threatens this world and those of us living inside it. One of those threats happens to be virus infected cells, who were indeed once normal cells of this body. But the virus changes them, and at that point no one can help them anymore."

Feeling he should join in, reassure the erythroblasts that what AC told them was accurate, 4989 spoke up. "That's when we come in. Those infected cells hurt everyone they encounter, infect others, little by little damaging this world, potentially even destroying it completely; so us leucocytes make sure they don't. Make sure everyone else is safe."

AC nodded. "I know he seems a little weird…"

"I thought we agreed that I'm adorably eccentric?" 4989 chimed in puppy-eyed.

"Yes, yes you are," the auburn hair confirmed with a teasing smile, tapping his nose, as she liked to do, and he couldn't help but think back to the liver, a warm feeling flickering in his chest at that memory. Now that he thought about it, a lot of what she'd said here kind of mirrored what she'd told him drunk. He smiled; it was nice, touching even, to have confirmed that she'd meant everything, inebriated or not. Meanwhile AC was already addressing the children again. "The point is he and most of the other immune cells are very nice once you get to know them, they're here to protect you. They will never harm you or any healthy cell. It's just that they can get really intense sometimes, when fighting all those monsters." And the boy nodded understanding.

"It's kinda hard to fight calmly," 4989 murmured abashedly.

The erythrocyte opened her mouth, but stopped, suddenly remembering something. "My delivery!" AC jumped back to her feet, rushing to her cart. "I'll be back in a minute!"

Oh, right! That's why they had come here in the first place. "Okay!" As soon as she'd taken her cart and ran off, 4989 realised something; he was alone with the erythroblast. He looked to them, uncertain what to do and a little nervous. He didn't want to undo what trust had been built. Then his eyes spotted the ball, currently lying forgotten on the lawn just out of arm's reach. "So, what were you guys playing?"

Chapter Text

Bone Marrow
Part 2

It only took AC a few minutes to find the right building and deliver the oxygen. She was far from the only erythrocyte around, after all there were many cells working here, who needed the vital gas, making it even easier for the auburn haired cell to find her way around. When in doubt, follow the crowd.

The downside was that she had to wait her turn, but finally she got her box of carbon dioxide, swiftly left the building again, her cart waiting just outside. She was a bit nervous about 4989 being alone with the blasts, not because of something he might do, but because it could potentially be really awkward for him, considering the circumstances.

At least her stories seemed to have helped make the children more comfortable around him.

AC looked to the bracelet 4989 had made her, covering up her scar. Funny how things had worked out since that fateful day; nowadays she could see the pale bite-mark and recount the event without it sending shivers down her spine. That day she had been certain she would die.

.

Close to the stomach AC noticed a commotion in the blood vessel, a crowd of fellow erythrocytes that had gathered around something, or someone. Their voices sounded anxious and she approached them, curious as to what had occurred here. If there had been an attack red blood cells would be fleeing after all, so something else must have happened.

What she hadn't expected was to see AB 2934 lying unconscious on the ground.

AC gasped horrified, her box falling to the ground, but no one paid attention to her. It hadn't been all that long since they had met at the liver, and sure, she had looked tired then, but now AB 2934 was pale as death, her body gaunt almost reduced to her cytoskeleton. What had…how?

AC felt hollow, her mind struggling to process what she was seeing. It seemed unreal. She was not even really hearing the other erythrocytes around her anymore, and barely noticed the crowd parting when a few leucocytes appeared. Only when someone bumped against her shoulder, did she register their presence, two bloodied neutrophils and a natural killer cell.

One of the former kneeled down next to AB 2934."Hey, are you alright?!" a neutrophil with rather fluffy hair asked, as he shook the erythrocyte's body, but she only swayed lifelessly in his arms.

'Move', AC pleaded silently as she watched, begging for a sign of life. His fingers reached for her throat, but judging from his expression didn't feel anything.

"She's dead," the NK cell noted factually, her face a blank, and AC's haemoglobin twisted painfully inside her chest. She had assumed, but to hear it confirmed...

"But how?" the neutrophil exclaimed confused. "I don't see any injuries."

"No idea," the other replied, sounding worried.

"Let me see." AC's insides turned to ice, when she watched the female lymphocyte roughly grab AB 2934, all but tearing her from the other leucocyte's grasp. The insensibility with which she treated the body disgusted and horrified the auburn haired erythrocyte. Did immune cells have no empathy for their fellow cells? It was sickening.

The NK cell continued to examine AB's body and talked with the two neutrophils, but AC couldn't hear what they said. Until the fluffy haired neutrophil pointed at the bracelet.

"It's moving!?" the other white haired cell exclaimed, his hand reaching for his knife, ready to strike.

That's when AC saw it. Like a small worm the supposed bracelet had begun to wriggle. It bloated and several dents showed, before it suddenly just fell off. And then it split along the dents.

"It's multiplying!" the NK cell shouted, blade drawn, as all five parts began to move again, each a new worm. "Kill them quickly!"

Around her the watching red blood cells began to scream in panic and started to run, desperate to get as far away from the worms as possible. AC however was paralysed. The bracelet…the bracelet AB had given her too…

The fluffy haired neutrophil jumped back on his feet, blade drawn. "What are they?"

"No idea, but we can't let them escape!" the other replied, stabbing the closest worm, pinning it to the ground, where it wriggled desperately for a few moments before lying still.

NK cell's blade cut two apart in one move and the fluffy haired one got another. And the last was coming towards AC. She saw it, but her mind had turned blank, her numb body seemed like dead weight, unable to be moved, and she could only watch it closing in.

"One is getting away!" she heard a neutrophil yell, pointing at the worm, rushing towards her. But before any of them could deal the killing blow someone else stepped forth.

"Not to worry."

The worm leaped at her like a striking snake, but from the corner of her eye AC saw a green sleeve, and the newcomer caught the creature while still in the air.

"Dendritic Cell."

The green clad cell stepped past AC and spoke with his fellow immune cells, but AC wasn't paying attention, her eyes wandering to her own wrist, still trapped in that trance-like state. That thing…she had the same thing…it was…eating at her. It was…killing her.

"Please, help me!" AC's vision was blurry as she broke into tears, the drops warm against the membrane of her cheeks, finding herself shouting in desperation.

Nonetheless she somehow saw all four leucocytes turning towards her, the fluffy haired neutrophil reaching for his knife again, clearly alarmed. "What is it?"

She was afraid, but she had to tell them. What choice did she have? "AB 2934; she gave me this bracelet when she came from the liver! I think it's one of those things!" AC cried, her throat feeling constricted, making it hard to speak.

The neutrophil with the fluffy hair kneeled down by her side and took her arm, lifting her wrist, much gentler than she'd expected, his light grey eyes studying the…'thing' around it.

He proceeded to grasp the worm and tried to surprisingly carefully remove it without hurting her, only the blunt side of his blade touching her membrane, but to no avail. "Damn, my knife can't cut through it," he growled and moved on to try to tear it off with bare hands. It yielded similar results.

"If these things are feeding on erythrocyte, maybe it would be saver to simply kill the host," the NK cell suggested nonchalantly, not even a hint of pity or concern anywhere in her expression. AC froze up. No…

"What?!"

Both neutrophils moved their bodies between her and the once more paralyzed erythrocyte, who now only saw the fluffy haired neutrophil's back. Then the other spoke. "NK, we're supposed to keep the body safe, which includes the cells living in and providing for it. If we can save her, we will," he declared coldly.

The female lymphocyte didn't reply immediately, but then the erythrocyte eventually heard her sigh. "Fine. Show me the damn thing already."

The fluffy haired neutrophil moved aside, but remained next to AC, while his colleague addressed her. "Go on."

Would she really not hurt her? Still frightened AC hesitantly raised her arm, fighting to hold back new tears. She didn't want to die. Impatiently the NK cell then grabbed the extended arm, pulling her closer, making the auburn haired erythrocyte flinch. From the corner of her eyes she saw that both neutrophils seemed tense, but surprisingly their eyes were not on her, but their fellow leucocyte and her sabre. Looking down AC saw that the tip was pointed at her chest. One stab would be enough.

But the NK cell only cut through the crimson ring, slowly, methodically, cytoplasm gushing, probably what the worm had already absorbed from her. Dead the foul thing briefly shivered before simply falling off, merely leaving a few red dots behind on AC's pale membrane, likely a bite-mark.

"There you go."

AC stared at her newly freed wrist, Dendritic Cell gently placing a reassuring hand on her shivering shoulder. Was that it? Was she just going to be alight? The neutrophil, whose hair covered his right eye gave her a few moments, before he spoke to her again. "Do you know anyone else who's got one of those things?" he asked her calmly, though his visible eye looked at her kind of intensely.

Intimidated, AC slowly nodded, averting her own eyes. "As far as I know 2934 only gave them to RD 9843 and AE 3803…"

"AE 3803?! Are you sure?!"

AC jumped, seeing that the neutrophil's eye had widened. Now he really looked scary, especially with that cytoplasm all over him. "Y..yes," she stuttered fearfully and confused. "Why?"

"1146…" the other fluffy haired neutrophil began.

"You go find the other!" his colleague just shouted and ran off without any explanation.

Had she said something wrong?

"Right. Red Blood Cell?"

Timidly AC met the leucocyte's grey eyes. "Huh?"

"Can you tell me what RD 9843 looks like?" he asked with a soft and warm sounding voice, while displaying a gentle smile. "It would really help with our search."

Right; with so many erythrocyte it could take forever to find RD otherwise. "Oh,…sure." As she described the other red blood cell as detailed as possible, AC couldn't keep her voice from stuttering, her gaze always wandering back to the bite mark on her wrist. It had been close…so close.

Though his posture told her that the fluffy haired neutrophil was edgy, probably wanting to start his hunt, he didn't pressure her, only nodding every now and then. AC finished by telling him RD 9843 approximate destination, and to her surprise he didn't immediately run off, instead he took his transceiver and passed on the information to his fellow neutrophils.

When he looked to her again, she saw him turning his head from the corner of her eye, AC was again focused on her wound, nibbling on her lower lip. Just as she was about to get lost in her tumultuous thoughts and emotions, his voice broke through to her, and he was still giving her that soft smile. "Hey, you're going to be alright."

.

AC smiled to herself. Back then she'd been too shaken and frightened to appreciate his kindness, not just when speaking to her, but also later when he'd brought her to the bone marrow, before joining the search for the other infected.

Her friends had been so relieved to see her again, upon her return to the bloodstream a few days later, as they had heard about the incident, but not known whether she'd been affected. Looking back now, the auburn haired erythrocyte felt guilty for having mentioned to them that NK had wanted to kill her in her retelling of the events. Maybe things would be different now, if she'd neglected to include that particular detail.

And perhaps she should have found the courage to approach and thank 4989 earlier than she had.

AC stopped on the road, looking ahead to the lawn where she'd left said neutrophil with the children, a smile spreading across her lips once more.

She had wondered if he'd continued to tell them stories, but instead the erythroblasts were playing again, running across the grass, kicking the ball back and forth between each other. 4989 was among them, the girl with the injured knee on his shoulders, excitedly pointing at where the ball was at any given moment.

It was however obvious that the fluffy haired neutrophil was holding back, only ever passing to one of the children immediately, never going for the goal, which incidentally was between the posts of a set of swings.

AC could hear the shouts and laughter, her smile widening when a blast made a goal and the injured girl cheered for her teammate, 4989 lifting her up above his head.

Since her talk with Dendritic Cell AC had wondered what she should do if the worst were to happen, if the rift could not be mended, whether she should remain with her old friends or embrace her new ones. Not just 4989, but also the other three and AE 3803, even though she'd met the other erythrocyte only a few times thus far. And after having looked back at so much these past two days, her first meeting with 4989, the time at the liver, all the hours spent together and now as she watched him play with the little erythroblasts, laughing just as brightly as any of them, she realized something; should it come to that, her decision was already made.

"Big sis, big sis!"

4989 turned his head, when he heard one of the boys shout, seeing AC 4293 join them, her cart once more parked by the side of the road.

"Big sis, you've got the even the teams," the boy told her, tugging insistently at her jacket.

The auburn haired erythrocyte chuckled and placed a hand on the child's head. "Don't tell me our neutrophil is being unfair."

"They're winning."

"Are they now?" AC looked to 4989, who quickly averted his gaze, whistling innocently.

Truth be told he was barely involved in the game, but he was hardly going to complain when it meant she'd join in. Still, it wasn't like any of the kids were actually upset; truth be told no one was counting, and both teams were going for the same goal. If anyone was losing, it was the goalie, but that girl too seemed unperturbed, even when she let a ball through.

"Alright, who's in my team?"

A few second later the game was back on and for the first time 4989 actually had to defend the ball whenever it was passed to him, as AC was certainly not afraid to challenge him for it with a smile on her face, making his mitochondria pound.

When he had first approach her all 4989 had really wanted was to find a way to alleviate the fear most erythrocytes felt towards leucocytes, perhaps gain a friend in the process. Even if the former hadn't quite worked out yet, not that he was giving up on that particular project, especially now, there was something else. As he watched her during the game, beaming from ear to ear, having so much fun, smiling at him, he wondered for a moment if this was how 1146 felt whenever he looked at AE 3803.

Eventually it was decided that the game ended in a draw, not that anyone actually knew the score, and the adult cells had to depart again. After all 4989 was technically still on patrol and AC had to get the CO2 to the lungs. The children were sad to see them depart and continued to wave and shout goodbyes even when AC and 4989 were already back on the road, the two turning around one more time to wave back.

"Thank you…for what you told the erythroblasts earlier," 4989 suddenly began as they walked past the main complex of the vast school, a subtle, but nonetheless grateful smile gracing his face.

"Happy to help," AC replied, happy that she'd been able to assist. "But you don't need to thank me; I was just telling the truth after all." And she was glad for anyone who would listen.

For a second his cheeks featured a pale pink hue. "Still, meant a lot to hear you say it," the neutrophil confessed. "And I'm sure it made a difference for those blasts to hear those things from you, rather than me."

"Possibly, yes." A senpai probably was more persuasive in this regard, which suddenly gave her an idea. Playfully she nudged 4989 with an elbow. "Maybe I too should teach them about neutrophils," she told him with a grin, though judging by his expression turning from surprised to elated, he'd realised that she was being sincere.

"You're very welcome to come along, if the macrophages allow me to visit," he told her happily, almost sounding relieved; maybe he'd been nervous about trying to teach an entire class of possibly frightened erythroblasts on his own.

"Loved to." That promised to be fun, or at the very least interesting. Most importantly however it would hopefully make a difference.

The two continued on, walking side by side in comfortable silence, occasionally crossing paths with other erythrocytes, and even sometimes hematopoietic stem cell, who were looking after the blasts playing on the grounds.

When they neared the exit, 4989 suddenly perked up, his smile widening. "Is that?"

"Huh?"

"It is!" The fluffy haired neutrophil exclaimed brightly and started to wave excitedly. "Sensei!"

Ahead AC spotted another neutrophil on the road, who looked up when 4989 shouted. After a moment of confusion or perhaps just surprise, the other leucocyte smiled. "Well, there is someone I hadn't expected to see today," he greeted them once they reached him. Close up he looked older than most neutrophils AC was used to see, and there was surprisingly calm aura surrounding him, which was reflected by his voice. "U-4989, good to see you again."

"You too, sensei," her friend replied happily.

The older neutrophil with very short hair, whose tag identified him as U-1110, turned to the red blood cell. "And this is?"

"AC 4293; nice to meet you."

"Likewise, miss," he told her with a friendly smile, before turning to 4989. "She's…?"

"She's a friend," 4989 quickly answered, almost hastily actually, and confusingly AC saw that faint, pink hue colouring his usually pale cheeks again.

"I see," 1110 said, sounding amused.

Recognising the awkward atmosphere, AC quickly decided to jump in. "You were one of 4989's teachers?"

"Yes, I indeed had the pleasure to tutor him and his friends. Seems it was only yesterday you all graduated."

"It wasn't all that long ago," 4989 noted.

His old sensei nodded. "True, but your no longer a band cell either," a concerned frown flashed over his features. "And from what I've heard you all have been through quite a bit in such a short time nonetheless."

The fluffy haired neutrophil however grinned. "Good thing then we had you as our teacher."

"You know, I was never quite sure if you actually listened to me," the other mentioned, though it seemed to be more teasing than earnest criticism.

"I did," 4989 protested, before looking away bashfully. "I just sometimes had my own interpretations of your lessons."

1110 chuckled. "I suppose that is one way of putting it."

"Sounds like fun times," AC noted, considering what she already knew of the four neutrophils, especially 4989. She had little difficulty imagining him as a true little troublemaker as a child, and she remembered 2626 mentioning something about a bow.

"The four of them have certainly been among my more...entertaining students," the teacher admitted. "Perhaps next time you stop by I could share some stories, if you are interested."

That sounded too good to be true. "I'd love…"

Suddenly 4989 covered her ears with his hands. "Ah, I don't think that will be necessary," he hastily told 1110. "Please."

AC however only giggled at his reaction grasping his hands with hers, trying to pull them off; they didn't exactly keep her from hearing what was being said anyway. "Hachikyu-kun; don't worry."

"Sorry, but Dendritic Cell having photos of every embarrassing moment in my life is bad enough," he told her, sounding a little desperate, a pleading look in his eyes, when she looked over her shoulder.

Was he worried that she would wind him up with whatever she learned? Sure she'd teased him one time or another, but that he would be this worried about her finding out more about his childhood seemed strange, and just a little sad. "Oh, come on; whatever he tells me can't be worse than your first driving attempt with the cart."

"In my defence that bump came out of nowhere."

"Do I want to know what you tried to do with an erythrocyte delivery-cart?" 1110 chimed in, one of his eyebrow raised.

The fluffy haired neutrophil rubbed the back of his neck. "Would you believe me if I told you that it wasn't in any way combat related?"

"No."

"Then probably not," 4989 admitted, smiling innocently.

1110 sighed and shook his head. "Haven't changed a bit as I see." Nonetheless he quickly smiled again. He looked content to AC, but then his gaze wandered to the nearby school building. "Sadly I'm afraid we're going to have to catch up some other time."

"Giving another lesson?" 4989 asked him, finally pulling his other hand back from AC's head.

His former teacher shook his head. "No, we had an invasion earlier today," he explained, taking the two by surprise; it was truly rare that any pathogen made it this far into the body, and at least to AC it was terrible to imagine in what danger the blasts had been in. "It was successfully repelled without any problems, but I haven't seen two of my students since."

Now 4989 smile vanished for good. "Do you think…?" but he broke off, perhaps not wanting to finish the sentence, and AC's haemoglobin twisted.

1110 however shook his head, despite looking just a little troubled. "No. Knowing them they have used the opportunity to go explore the bone marrow," he gave his former student a meaningful look, with just a hint of a smirk. "Just like some other myelocyte once."

"Thought it was a promyelocyte," 4989 mumbled sheepishly.

The other neutrophil chuckled. "In any case, I still have to find them, preferable before they get up to something."

"We'll keep an eye out," AC promised him.

"Thank you, I appreciate it," he told her, smiling kindly. "It was nice meeting you, miss."

"Likewise."

"See you around, sensei."

The three cells parted ways again, 4989 waving his old teacher goodbye, as they started to walk. AC had to admit that she was tempted to come and see U-1110 again, learn a few things about her friend's past. But she didn't want to go behind his back, betray his trust.

"Would it really be so bad, if your old sensei were to tell me some stories?" the auburn haired erythrocyte finally asked after a while.

Her friend blushed yet again. "Well, some of them are rather embarrassing," 4989 confessed.

"I'm counting on that," AC joked, but he only pulled a face, making her place a comforting hand on his arm. "Hey, don't pout; nothing he could tell me would make me think any less of you. But knowing you as well as I do, I cannot help but think that there have been some rather…interesting events I missed out on. I mean you as a boy? You must have gotten up to all sorts of mischief."

"I seem to have made quite a lasting impression," the neutrophil noted, but he sounded more amused than upset.

"Adorably eccentric, remember?" AC chuckled and saw him grin in response, much to her delight. Maybe she could get him to tell her some stories instead. He'd told her plenty of his job already, even re-enacted some with the help of the platelets, so he wasn't exactly secretive.

It looked like he wanted to reply something, but just when he opened his mouth, his receptor went off, ringing loudly in both their ears. "Stay behind me!" he told her stepping protectively in front of her, hand flying to one of his knives. "Antigen!"

They were still within the bone marrow, at the outskirts of the school, but the street before them was empty, with only a few erythrocytes up ahead, who went about their duties undisturbed. But that wasn't the only way.

"The side road!" AC noted out loud, looking to a small path to their right, just between the last building and the crimson wall that marked the border of the red bone marrow. She was certain that she could hear voices coming from there.

4989 merely nodded, perhaps having heard them as well, and approached the alley. AC hesitated for a moment. She knew that she would be of no use in battle, but she hardly wanted to simply wait and see what happened. Finally she left her cart behind once again and followed her friend, just as he disappeared behind the corner.

Making sure she kept that distance, just to be safe, AC approached the alley and heard a chuckle that sent shivers down her spine. No cell possessed such a voice. She turned around the corner and saw up ahead two myelocytes, one on his knees, holding his left arm, while the other stood in front of him, holding aloft his small dummy knife. What captured her attention the most however was the creature looming before them, a red bacterium, its membrane looking almost wax-like, with six arms, all ending in three clawed digits. It's pale, greyish eyes narrowed when it saw 4989 running towards it, and it revealed needle-like teeth as it snarled.

Serratia marcescens

An opportunistic pathogen, which can infect various regions of the body, from the respiratory tract and eyes to the urinary tract. Less commonly it can also cause osteomyelitis (infection of the bone and marrow), endocarditis or meningitis, and is gaining relevance as a causal agent of nosocomial infections, which are infections gained after/during hospitalisation. Serratia are capable of producing the pigment prodigiosin, which can discolours contaminated food, like bread, red/blood-red.

"Get away from them!" 4989 shouted, rushing past the two children, blocking a clawed hand with his knife that had been aimed at the standing myelocyte's head. "AC! Take the boys!"

"Right!" She ran the last few steps and grabbed both myelocytes around the waist, pulling them back and away from the bacterium.

One of the boys looked at her confused, his eyes as wide as dinner plates, while the other watched as 4989 engaged the red pathogen, dodging another one of its orange appendages. They saw him cut off first one, then two more of the creatures arms, hearing it hiss in pain, while the neutrophil closed in.

AC knew that he'd faced countless of those monsters, nonetheless her insides twisted as she watched him fight. She even realised a moment later that she was holding her breath.

However there was fear now in the pathogen's pale eyes as it backed away, perhaps considering escape. Desperate it launched all three remaining arms at 4989, claws flashing, but the neutrophil leaped forth, head lowered, and thus avoided the attack completely,though AC gasped at how close it was.

"Now die!" He slashed upward, cutting across the bacterium's torso from hip to shoulder, bright red cytoplasm gushing forth.

AC breathed out relieved as the germ collapsed, 4989 stabbing it one more time to make sure it was dead. She slowly let the boys down, their feet gingerly touching the ground. The erythrocyte saw that they were focused on the adult neutrophil as he examined his kill and pulled his blade out of the body.

"Are you boys alright?" AC asked, crouching down next to the myelocytes, gaining their attention, both turning around to her.

"I'm alright, but 3521 got hurt," the boy, who had stared at her with big eyes earlier told her, pointing at the other.

"Where?"

The boy with the short ponytail hesitated. "My arm," he finally admitted with a low voice, lifting his left one a little. "One of its claws got me."

4989, the front of his uniform completely bloodied, joined them and had evidently heard that last bit. "Can I see?" he asked friendly, as he crouched down as well. The boy complied, if slowly, and with the cleaner of the two gloved hands the fluffy haired neutrophil took the injured arm. There were three clean cuts, thankfully only bleeding a little, and judging from his expression AC figured that her friend wasn't too worried. "Nothing deep, that'll heal quickly," he confirmed with an encouraging smile and let go of the arm again. "What were you boys doing here anyway?"

For a few moments the two myelocytes looked at each other, before the injured one lowered his gaze and the other somewhat meekly replied. "Well, we heard about the repelled invasion and wanted to check out what kind of germs they were."

The other nodded. "That's when we saw something strange and followed it all the way here."

"And you didn't get an adult?" AC asked, a little astonished by how bold the two had been, but maybe this was a myelocyte thing. They were trained to become fearless fighters after all; that had to manifest sooner or later, though these two had apparently found their limits.

"We just wanted to take a look," the uninjured boy claimed sheepishly, snivelling a little. "But as soon as we found it, it attacked us." And with those dummy-knives, they'd been defenceless.

Well, then at least they hadn't planned to take it down by themselves. "You were lucky," the erythrocyte noted, and obviously feeling guilty, the two boys hung their heads.

"Let's get you two back; U-1110 is still looking for you two," 4989 mentioned as he stood up, making the children flinch.

U-3521 glanced over to his friend. "Sensei is going to be so mad at us," he mumbled.

But the fluffy haired neutrophil shook his head. "He's going to be glad you two are still alive," 4989 assured them, before pointing at himself. "Trust me, I too was a troublemaker, but he never bit my head off. At worst he's going to scold you for not getting help." His words seemed to ease their minds, and slowly both of them nodded.

Together they all left the alley, going back to the main road, surprising an erythrocyte, who happned to pass by and quickly hurried along to stay out of their way. AC decided to leave her cart behind for the time being, instead offering a hand to the injured boy, who still looked quite nervous. At first confused he looked at her hand, before hesitantly taking it, AC slowing her pace a little to match his. 4989 meanwhile was busy removing drops of cytoplasm from his face and neck, probably worried about frightening other children with his appearance.

The little group soon reached the main school building, where they had parted ways with U-1110 earlier, seeing that apparently all the children were headed there, probably gathering for the next lessons. Among them was a very familiar group of erythroblasts, and they recognized them as well.

"Big brother! Big sister!" Some of them shouted, as they all came running towards them, bright, heart-warming smiles on all their little faces. AC could practically see 4989 light up when he heard them calling him 'big brother', even as he quickly put away his bloody tissue.

"Looks like we've got a welcoming committee," he noted happily, just before the kids reached them.

They looked a bit aghast at the sight of 4989's red jacket, but their attention was quickly drawn to the myelocytes, when they realised one of them was bleeding. "What happened to Nii-san?" one of the girls asked concerned.

AC once again crouched down to be at eye-level with the children. "These two here stood up to an evil germ, trying to invade the bone marrow, but 3521 here got hurt in the process," she calmly explained, reassuringly squeezing the myelocyte's hand. "Could one or two of you run ahead and get one of your teachers?"

"On it, big sis," one of the boys this time promised, tugging another by the arm and the two quickly ran off together.

"Did you kill it, big brother?" the girl with the scraped knee meanwhile asked 4989 curiously. "The germ?"

"Of course," the fluffy haired neutrophil confirmed. "It's my job to protect you after all. Made a bit of a mess though," he admitted, scratching his cheek in an almost bashful manner.

Now with a small entourage to escort them, AC, 4989 and the myeloblasts enter the school building, attracting quite a bit of attention from the other students, many of which stopped or at least slowed down to watch. AC however didn't really care, instead she was busy watching and listening, as the erythroblasts asked the myelocytes all sorts of questions, mostly about the germ-incident. The young boys were mostly bemused, answering with one or two words at most, and the red blood cell assumed that neither of them had ever even spoken to an erythroblast before, and were a bit overwhelmed by their curiosity and friendliness.

It seemed like their visit to the bone marrow had already paid off in a small way.

When she looked to her friend, AC saw that 4989 was just as if not even more delighted by this development than her, grinning brightly from ear to ear. She loved seeing him this happy, and why shouldn't he be; his goal now seemed actually obtainable, if not for their generation, then perhaps for the next.

Chapter Text

Fireworks

Part 1

"Have a nice day."

"You too, and thank you again."

"My pleasure."

The door closed and AC 4293 sighed satisfied, stretching her arms as she descended down the staircase. Another nutrient delivery done and it was finally time for her long break. As she slowly, almost idly, stepped outside onto the street, AC wondered where she should spend her spare time. While she had already thought a little about it on her way up here to the pharynx, she'd not yet made a decision. What time was it anyway?

The body was always active, making it sometimes difficult for the red blood cell to tell what part of the circadian rhythm it was in.

Circadian rhythm

The circadian rhythm (also referred to as the internal clock) is the internal process that dictates our natural sleep-wake cycle, with one cycle taking around 24 hours. Aside from internal factors, the rythm is however also influenced by the local environment/external influences such as light or temperature.

Perhaps she should just head for the nasal cavities, let her feet recover at the hot springs; it seemed like the best idea really.

Without a box or basket in hand, travelling across the body was certainly more comfortable and thus, despite a long shift behind her, AC found herself overtaking many of her still working colleagues as she moved quickly through the bloodstream up towards the head.

When she approached the nasal area, having left the naso-pharynx behind, the erythrocyte could feel the air humidity rise, indicating that she was nearing her destination. At first it was accompanied by a cool breeze, but soon the temperatures rose and the buildings around her began to change. Apartment buildings became smaller until they were getting replaced by little shops and a sign above welcomed those following the road to the nasal cavities.

AC could smell freshly baked goods and heard water rushing in the distance, despite the numerous chatting cells, both erythrocytes and locals, the latter of which wore white yukatas and steel blue jackets.

The erythrocyte searched her way through the many streets, deciding what to treat herself to, when a white uniform caught her eyes. She had passed by many neutrophils on her way here, but she recognized the fluffy hair and when he turned his head a little, she could see his face and tag.

Evidently he hadn't noticed her yet in the crowd of red blood cells, otherwise he would have already reacted, which gave AC an idea. Her lips curved into a mischievous grin.

As inconspicuous as possible she made her way over, making sure she stayed right behind him. Luckily he didn't turn around, merely remained standing at wooden pillar, supporting the low roof above one of the many footbaths around this area. Finally she'd reached him and blew at his ear.

4989 jumped in surprise, making her giggle, and quickly turned around with a startled expression on his face, which upon seeing her immediately changed. "AC!" he greeted her with a broad, warm smile. "What are you doing here?"

The erythrocyte shrugged. "I'm on a long break, so I thought I stop by, rest my feet, maybe get a bite to eat. I didn't know you were here though." But she was absolutely thrilled that he was.

"Long break?"

"Yeah."

Suddenly she saw a twinkle in his eyes. By now she knew all too well what that meant; now he had an idea. He took her by the wrist. "Come."

"Where are we going?" she laughed, amused to have been right.

"It's a surprise," 4989 replied with a grin on his face, looking actually quite excited. "Trust me." Oh, that wouldn't be an issue.

Despite her rather tired feet, AC let herself be guided through the streets of the nasal cavities, yet soon realised that they were leaving the area, even if she couldn't quite tell what direction they were headed. Now confused, but still curious, she continued to follow 4989, as he led her through a myriad of roads and alleys. How did he know all these paths? Were they going deeper into the head?

They walked at a brisk pace for several more minutes, until they found themselves in yet another narrow street, just broad enough for one person. It was rather dark here, but past 4989's head, the erythrocyte could see light up ahead.

She felt him tugging at her wrist again, just as he stepped out of the alley, and all but pulled her in front of him. AC's eyes adjusted…and widened.

They were standing at the edge of a small plaza, in front of them a vast window front, larger than the ones she'd seen in either the stomach or the lungs. And beyond that, she saw the perhaps strangest buildings of the entire body. At first they seemed like grey towers, except their design had been inspired by trees, all connected with each other through countless, massive branch-like cable bundles, the information receiving dendrites and information sending axons respectively. Yes, these were neurons, they were in the brain.

Looking around AC noticed just how many circulating cells had gathered here. She'd been in the brain before, but she'd never seen so many people at once here, the plaza was almost full. Wait, could it be?

"Surprise," 4989 chirped merrily beside her.

AC turned to him, eyes still wide open, struggling to find words as her mind was racing. "Is…is it…?"

He gave her another grin, making the haemoglobin in her chest leap for joy and took her wrist again. "Come, this way."

Surprisingly he didn't drag her into the large crowd, but instead he guided her along the wall to one of the pillars that supported this viewing-area's overarching dome.

"Up there is a marginating pool," he explained, pointing up. "Just follow my lead."

Deftly 4989 started to climb up the pillar and only now did AC see that its surface was not entirely smooth, featuring several dents, just enough for feet and hands to find purchase. Slowly she followed him, having to pay a lot more attention to where she placed her feet. When she neared the marginating pool at the top, 4989 offered her a hand and helped to lift her up to a small platform, easily big enough for one person, however not quite for two.

The fluffy haired neutrophil made as much room as possible for her to his left, yet they still ended up shoulder to shoulder and legs touching. They were rather high up, at least for her liking, about three or four storeys AC guessed as she looked about, and so she leaned a little further towards him, a touch worried about slipping off.

But then she saw the view. When she'd made plans to visit this place, she'd always been concerned about her view being blocked by countless heads, but now to her left she could see the entire window front and the light grey 'forest' beyond.

AC couldn't help but feel giddy. The brain was always active, even now flashes danced across the cable bundles, but during dreams certain areas became so much more active. Many called it fireworks, though it was perhaps more reminiscent of a colourful lightning storm.

She had always dreamed of seeing it with her own eyes, yet she hadn't expected to get a front row seat…in a manner of speaking.

"Best view you're gonna find," the neutrophil told her and winked, clearly quite pleased.

"This is beautiful," AC exclaimed, turning to him with a bright smile. "Did you…?"

"Remember that you always wanted to see REM-sleep?" he finished her sentence before she could with a soft smile that made her feel even warmer inside. "Of course."

She opened her mouth to thank him, but on the spur of the moment placed a hand on his shoulder, leaned in and pecked his cheek. AC had just enough time to see him blush with that pale pink she adored as she leaned back again, before the lights in the viewing area dimmed, announcing the beginning of a REM-phase.

4989 felt every single of his mitochondria hammer in his chest and his body freeze up, when her lips touched his cheek. It felt like electricity was coursing through his body, making his toes and fingers tingle.

Just a moment later the lights dimmed and AC turned away, looking expectantly to the neurons. The fluffy haired neutrophil gulped and gingerly touched his cheek with his right hand, as the other would have brushed against her arm.

Since they'd been to the bone marrow a few days ago he knew that both 1146 and Dendritic Cells had been right. He did have feelings for AC and he hadn't really been able to get her out of his mind since. And now she'd kissed him.

Meanwhile the fireworks began. Rapidly lightning ran across the branches, jumping several times along the cords before reaching the next neuron, hundreds at once, illuminating the viewing area. The light of each was refracted a little differently, creating myriads of colours. Most had shades of blue, others shone yellow, a few were even violet or red. There one second and gone the next with a flash. But frankly 4989 didn't pay much attention to the spectacle.

His eyes were on AC, watching her, bathed in that multi-coloured light. He couldn't see her face all that well, but he could tell that her mouth was slightly opened.

4989 leaned forward to get a better look, just as AC gasped with amazement, and he smiled happily at her reaction. She was mesmerized, her eyes shining, reflecting the colourful flashes, so completely focused on what was happening before her. He loved seeing her like this, so full of joy, amazement, almost giddy by her standards. It was then the neutrophil noticed that right now his head was all but resting on her shoulder and that if he were to turn his head, his nose would touch her cheek.

His own warmed immediately at this realisation.

Thanks to his help, 1146 and AE 3803 had confessed their feelings for each other at the retina, one of the most beautiful places in the entire body, and naturally 4989 had wanted to make his move somewhere just as breath-taking. She deserved that; he wanted to make it special.

He hadn't known where, but now they were here together to watch the REM-sleep unfold, the fireworks she'd dreamed of seeing. What better place was there? What better moment?

But now, sitting so close beside her, the fluffy haired neutrophil suddenly felt anxious. How should he go about it? Just give her a peck, like she'd done, or be bolder? No, a peck would be a good start and then wing it from there. 4989 swallowed nervously and suddenly regretted not having consulted 1146 about this. Surely he could have provided him with some tips.

He hadn't seen everything, but he remembered his friend taking AE's beret, so its peak wouldn't be in the way for the kiss.

4989 took a deep breath and slowly lifted his hand; it was trembling. This was it.

"U-4989, come in. This is U-2001"

No, no, no! Come on! Not now!

Suppressing a disappointed groan, he picked up his transceiver. "U-4989 here," he answered, hoping that his annoyance didn't show, still cursing internally, but of course his colleague couldn't know that he was interrupting. Still; why now of all times?

"Pathogens entered the body at the naso-pharynx. Get down there as quickly as possible."

Then he probably wasn't the only one being called. This could be serious. "On my way. AC…" 4989 stopped once he looked up, seeing that she'd turned her head; her face seemed only a breath away, and the heat returned to his. So close...but he knew the moment was already ruined.

"Guess you've got to go," she muttered. It took him a moment, but finally he was snapped out of his stupor, when he noticed how crestfallen she looked as she said that.

He didn't like that look one bit, it almost hurt to see it, and so somehow he managed to smile. "If it's a minor incident I'll try to come back," the neutrophil promised, hoping to cheer her up and to give himself hope. "But shouldn't it be, you don't have to wait around. Just enjoy the fireworks, okay?" AC gave him a small nod and he looked to the pillar they'd climbed. "You think you can get down from here?"

"Sure."

"Right." The others were waiting, he had to go. 4989 started to climb down, but stopped before his head disappear under the platform, looking back to her one more time. "See ya." It did not have the same enthusiasm as usual.

"Hachikyu-kun?"

"Huh?" She looked worried now and he saw her clenching her knees.

"Watch yourself, all right?" AC urged him, evidently trying to muster a smile of her own.

His mitochondria skipped a beat. "Of course," he promised, his smile turning into a teasing grin. "I'd never hear the end of it if I didn't."

AC watched him climb down and disappear into the same alley that had brought them here. The fireworks continued, but she kept staring at the alley, as if part of her was expecting him to return at any moment. Of course that didn't happen, but one could hope.

The erythrocyte remained on the platform, only occasionally glancing to the lightshow to her left. It was indeed beautiful, even more so than she'd imagine, but watching it alone now…it just seemed paler, less engaging. Her hand wandered to the spot to her right; even though she'd been sitting at the edge, she hadn't moved despite having plenty of room now.

She always hated it, when he was being called away and it never failed to make her worry for him just a little bit. Naturally she was convinced he'd make it back, but still.

Eventually the fireworks stopped, and the neurons assumed their normal communication pattern, a few flashes every now and then, but nothing to the scale seen during a REM-phase. Below AC the crowd dispersed, as the lights were turned back on again, leaving the viewing area near empty in the end.

For a while the auburn haired erythrocyte kept waiting in the marginating pool, hoping that 4989 would perhaps yet return.

But he didn't.

She spent her entire break up there just below the dome, however the leucocyte never showed up; in fact she didn't see any neutrophils around, which was admittedly rather strange. Perhaps the battle was still on-going?

Slowly AC climbed down again, careful where to place her feet, not wanting to slip off the small dents across the pillar. As an erythrocyte she wasn't nearly as proficient a climber as a neutrophil, yet somehow she made it down alright.

She knew she should have been happy after what she'd seen tonight, but she couldn't shake that sense of disappointment. One last time she looked around, before she headed back alone towards the lungs to start her next shift.

…

The next days passed quietly as AC did her deliveries in peace and alone. It surprised her that she didn't come across 4989 even once in half a week, though she wasn't too worried at first; finding each other in a big world like this could be difficult sometimes.

He'd started to wait around the lungs and heart, whenever he wasn't occupied, places he knew she had to go through every circulation, but that didn't guarantee anything. But not once did she even see him.

Admittedly she was starting to miss his company and began feeling a bit lonely as the days went by, her only conversations being with the cells she delivered to or other erythrocytes, most of whom were strangers or casual acquaintances at best. The sole exception was AE 3803, who proved equally glad to see a familiar face once in a while, as she had apparently not seen U-1146 in quite some time either. The lively redhead claimed not to be worried, but AC could see that if nothing else she missed her boyfriend, despite her trust in his abilities. The other erythrocyte understood all too well.

Soon AC found herself checking each neutrophil she came across, hoping to find 4989 or at least another familiar face, yet was disappointed each time.

It wasn't long until she first heard talk about the battle at the pharynx having spread up to the sinuses. The erythrocytes who had been there talked of a warzone, and even the nasal-hot springs were supposedly no longer safe. They were all concerned, but AC felt her haemoglobin twisting into a knot when she heard the news. 4989 had to be there, still fighting. He had to be. He wouldn't…?

No; he'd seen plenty of battles, he would be fine.

Nevertheless, with each passing day her doubts and fears grew. She considered searching for him, if only to ease her mind, but where to start? The entire upper respiratory tract seemed involved and while some rumours spoke of bacteria, others claimed the body was facing a viral infection; neither rumour served to ease her fears.

The longer and fiercer the fighting, the more likely it was that something could happen to him. Still, there was nothing she could do, nothing but wait and that perhaps frustrated her the most.

...

Almost two weeks after the REM-phase fireworks, AC was feeling desponded. She was taking a break near the liver, catching her breath before making her way up the inferior vena cava, not feeling the need to hurry. Up there at the lungs she would only hear the newest rumours again or the dreadful reports of red blood cells, who had actually been to the upper respiratory tract.

And so she lingered there on a lone bench along the road, taking her time with the glucose she'd gotten at a nearby vending machine, despite her absolute lack of appetite. But she had to eat, she knew that.

She was just eating fast enough to keep the ice cream from dripping to her fingers, and even once she was done, the auburn haired erythrocyte kept blankly staring at the discoloured wooden stick in her hand, before throwing it away into the bin beside the bench with a sigh. What was she doing?

There was no point in becoming anxious and he wouldn't want her to neglect herself like this. She chuckled softly; he would probably scold her, get her all sorts of snacks and shove them into her hands. And then eat half of them.

"AC?"

She looked up, but it wasn't the fluffy haired neutrophil. To her surprise it was CT 2980; they hadn't talked in weeks. "Hi," AC replied, sitting up straight, pausing to find the right words. "It's been a while."

The other erythrocyte smiled awkwardly. "Yeah, I guess. May I sit?"

AC hesitated again for a moment. "Sure." She'd expected this conversation, but did it have to be now? Then again, would there ever be the right time?

"Everything alright?" her friend asked as she sat down on the bench, clearly concerned but also cautious with her words. "You look troubled."

"I'm just worried about someone I haven't seen in a while," was her admittedly cagey reply, well remembering her last conversation with AD and his reactions.

Not that it was of much use. "You mean that neutrophil, don't you?"

"…yeah," AC sighed. "Look if you're here to lecture me and tell me how I shouldn't even associate with immune cells, I really don't want to hear it again. AD has made your position quite clear."

"I know, he's told me. And I think he was a bit harsh."

That wasn't something AC had expected to hear. "But you're still against it," she clarified.

Her friend scowled. "You being together with a neutrophil? Of course it troubles me, but I know I can't and shouldn't force you to break up with him…"

AC suddenly interrupted her. "Wait. Together? Break up?" Her eyes widened. "You think we're…?"

CT's expression changed into one of confusion. "You're not? But I saw him hugging you and carrying you around."

And she thought that meant…"No, that's just what he does and he only carried me that one time, because I'd been injured," the auburn haired erythrocyte quickly explained. "You thought we were…a couple?" For some reason that made her feel flustered, yet strangely enough also a tiny bit cheery.

"I assumed," CT admitted embarrassedly, blushing red. "The way I saw you two act around each other."

"Oh." If that was what she'd told AD 5022 before he'd confronted her. "No wonder my last conversation with AD went south so quickly."

Her friend covered her mouth with her hands. "I'm so sorry; I told him about what I'd seen, though he admittedly wasn't entirely convinced of my conclusion. He kinda refused to believe it. So, you don't care for the neutrophil?"

AC shook her head. "Of course I do," she insisted, more vehemently than she'd intended, and pointed towards the vena cava. "Right now he's out there fighting, he has been for almost two weeks to make sure we are all safe, that we'll survive, and I just can't stand waiting, not knowing if he's going to be alright." Or if he'd already fallen. No, she didn't even want to think that.

"But you're just good friends?" She could hear doubt in CT's voice.

"I…we…" She looked down to her empty hands, resting on her lap. AC wasn't blind. She had noticed that 4989 had started acting differently around her recently. So in a way CT hadn't been entirely wrong, and even his teacher U-1110 had noticed immediately, when 4989 had claimed hastily that AC was 'just a friend' with a flushed face. Perhaps she was reading too much into this, but she was clearly not the only one seeing it. Trouble was she wasn't sure about her own feelings, or at least she didn't know what to label them. "Just friends."

"Doesn't sound like 'just'," CT noted calmly and took a deep breath. "Look, whatever your relationship with him is or isn't, we just don't want anything to happen to you. Even if he won't hurt you directly, look what worrying about him is doing to you. Frankly you look like a mess. Downright anemic. What you need is rest and a decent meal."

The auburn haired erythrocyte couldn't help but smile a little, touched by her friend's concern. Perhaps they could still fix this somehow after all, but AC couldn't exactly relent either. "And as I've told AD, if being concerned for someone's wellbeing is a problem I shouldn't be friends with anyone."

"Perhaps, but erythrocytes aren't at the front lines every day."

Clutching her thighs, AC looked up again, a stern look in her eyes. "CT; I'm not abandoning him. I'm not giving up on any of my friends, old or new for that matter."

CT tilted her head, raising an eyebrow. "New friends? More neutrophils?"

"Mostly. You think I'm making a terribly mistake," AC added, reading her friend's expression.

"I'm worried," the dark haired erythrocyte reiterated. "I already lost one friend and now I feel like I'm losing another. But this time I just might be able to do something about it."

Seeing that hint of hope in CT's timid smile, elicited a sense of guilt within AC, her chest suddenly feeling very tight. "I never meant for this to happen…between us, you know?" But she'd neglected them both nonetheless, hadn't she? She hadn't told them about 4989 and created this mess. It took AC a moment to notice that she'd grabbed her plait in a subconscious effort to comfort herself. Well, now there was no other way but forward. "I could probably talk all day, try to explain, but would you perhaps consider talking to one of them? Just once?" If she could just properly introduce 4989...provided nothing had happened to him.

Her friend hesitated. "I can't say I want to," she finally admitted, looking a little more tense again. "It's…difficult to see them as anything other than the killers they are supposed to be. After all, we are defined by our function; it shapes each and every one of us, whether we like it or not. I can't help but wonder how you can be comfortable around someone, who has so much blood on his hands?"

"You're talking about bacteria and viruses."

CT's eyes narrowed. "And virus infected cells. In the end it is their cytoplasm they spill. We've all seen with how much enthusiasm they go into battle; you think they have any pity for the poor victims of the viruses, when they end their lives?" The dark haired erythrocyte hugged herself. "Even if he never lays a finger on you or any healthy cell, that remorselessness…it makes me uneasy, it makes my membrane crawl. I couldn't be around someone like that."

AC couldn't really argue with that. She'd gotten used to their occasional bloody appearance, however she couldn't say that she liked the sight, or watching them eat their fresh kills. It was easy enough for her to see CT's point of view, not too long ago she'd shared a very similar one. If 4989 hadn't helped save her that day, AC suspected her views would never have changed. But as her mind conjured up the images of battles she'd seen, all the times she'd watched the neutrophils, something occurred to her. "They pray, you know," AC remembered, seeing her friend look at her with confusion but also a bit of curiousness. "I've seen it after a virus invasion. When the battle was over many of the neutrophils prayed beside their last kill, before the macrophages collected them."

CT seemed to consider this new information for a while, at least she didn't reply for a bit. "I'm not doing much better than AD, am I?" she eventually wondered aloud, smiling somewhat sadly.

That had not exactly been AC's desired reaction, but her friend had listened. A start. "Well, neither of us is shouting, so there is that."

She giggled. "I guess. AC," CT paused as she stood up, judging byher expression searching for the right words. "Look if you ever need someone to talk, I'm there for you, okay? But there are just things I can't do. Not now…maybe not ever, I don't know."

"I understand." Sadly AC did, though it was hard to hear nonetheless. "No rush." She couldn't force her friends to accept a new point of view after all, only provide the opportunity for them to understand. Even if she had to do it over and over again.

"Well, see you around then."

AC nodded and her friend started to walk away. "CT!" The black haired erythrocyte turned around just before joining the crowd of passing cells, AC giving her a small but grateful smile. "Thank you."

4989 slid down the collapsed wall of a building, his boots sending debris flying. He grabbed two of his throwing knives, launching them at the streptococci below. One was killed in an instant, the small blade piercing the throat, but the other only imbedded itself into the other germ's shoulder. The purple bacterium snarled and stumbled backwards, just as 4989 leaped and threw himself at the enemy, ramming his blade into its chest. Two less, countless to go.

Panting the neutrophil looked around as he stood up, cytoplasm dripping from his blade, hearing the sounds of battle from beyond another building; clashing weapons, shouts and cries of pain. The area around him was in ruins, as if a massive earthquake had levelled it in a few moments, but in truth it was the result of long days of battle. Frankly he had no idea how long they'd been fighting, all he knew was that he was exhausted.

He was slightly shaking now that he stood still for a moment, and his limbs hurt from constant strain. The leucocytes were relieving each other from the front lines as often as they could, when they could, taking turns, but the small breaks were not nearly enough to really recover or let injuries heal. It took him so much strength just to stand.

His own uniform had seen better days as well. One sleeve was already missing entirely, the brim of his cap had been sliced in half, not to mention all the other cuts and tears, or the cytoplasm and dirt staining the once pristine white.

4989 checked his equipment, twisting his mouth when he realised that he'd used his last two throwing knives. Quietly grumbling to himself he kneeled down, hoping to pull the small blades from the corpses, knowing that he wouldn't be able to replace them for some time. They'd be dull, but two blunt blades were better than none. Just how long was this battle going to last? There just always seemed to be new germs to fight.

As he dug his fingers into the throat of one of his kills, he heard the debris around him getting disturbed. For a moment he wondered if it was another white blood cell, when suddenly his receptor went off.

His hand flew to his combat knife, drawing the blade as he all but jumped back to his feet. He spotted a blue shape in the corner of his eye and whirled around. Training and combat experience paid off, when his instinctively raised blade blocked a strangely shaped claw, no, more a spiked arm, ending in a single claw pointing at his face.

The creature before him was insect-like, moving on four limbs, its eyes large and alien. It hissed when 4989 blocked its attack, the sound followed by clicking noises it created by moving its interlocking fangs against each other. The neutrophil reached for a second knife and pushed his opponent's arm up, creating a large opening. One strike across the chest would do it.

In that moment something wrapped itself around his torso, trapping one of his arms, preventing him from drawing his second blade. 4989 involuntarily yelped in pain, when dozens of spikes dug into his body along the chest. Another one! How hadn't he noticed?

The mantis-like arms tightened their grip, and 4989 vision turned white as the pain flared up with new intensity, drowning out his fury for a moment. Damn it, damn it…

His other arm slumped down; the pain was making him dizzy and sapped the last of his strength, though somehow he managed to hold on to his knife.

And then a set of sharp fangs buried itself into his left shoulder, just beside his throat.

Chapter Text

Fireworks-Part 2

4989 heard a piercing scream and needed a moment to realise that the voice was his own.

Sharp fangs and spikes ripped into and through his membrane, pain ravaging his body, as the germ started tearing at him like a crocodile. It was a miracle it didn't bite out a chunk from his shoulder.

Everything started to spin before his eyes and the germ tightened its grip even further.

"Let me finish him," the other mantis-like bacterium suddenly hissed.

The one holding 4989 growled threateningly. "I captured him."

"Only because I provided a distraction." It showed the spiked arm 4989 had managed to block, the neutrophil now seeing that his blade had actually cut quite deeply into it. "I want the final blow."

The other snarled again, its fangs sinking a little deeper into 4989's shoulder. "Fine," it conceded reluctantly.

No, not like this. Light as his head felt, 4989 refused to end like this, killed helplessly by two random germs. The very idea served to refuel his anger, clearing his mind again for the moment. Neutrophils died fighting for their worlds, not as captives. There was no one here to help him, he couldn't hope for a last second intervention; this was up to him alone.

After all, despite being trapped, he still had legs and one free arm.

The germ before him lifted its arms for the final blow. Now!

His first kick hit the germ before him in the abdomen, making it flinch and lower its upper body. Yes! 4989 threw up both his legs, wrapping the left around the insect-like head, while pressing the right boot against its face. With a loud, cracking sound the neck snapped and the bacterium's body slumped down lifelessly.

At the same time he readjusted the grip on his knife and blindly stabbed at the germ keeping him trapped. He groaned when the fangs finally let got, his left shoulder sagging, while the bacterium cried in pain. Its grip loosened without letting go completely, yet now 4989 could turn his head. It hurt like hell, but the neutrophil could finally see its face. His blind attack had managed to hit one of the large eyes, though evidently hadn't gone deep enough.

Using what strength he had left 4989 threw his entire weight backwards, making the germ stumble and fall. Joint as they were they landed on top of each other and this time the neutrophil tossed only his head back, hitting his opponent's face. The grip loosened a little bit more and 4989 tore himself free, snarling as the spikes dragged across his membrane, leaving long cuts in their wake.

Nonetheless he whirled around and brought his knife down, stabbing the pathogen right between the eyes.

Two or three times the bacterium twitched and then lay still. 4989 collapsed.

He landed on his left side, hissing when a new wave of pain burned through his body. Lying beside his last kill, 4989 turned slowly until he was on his uninjured back and as he gasped for breath, he felt his knife slip from his numb fingers. The large wound on his shoulder was pulsing, leaking cytoplasm. He was losing too much of it and his vision was already blurring.

He had to move, he was too close to the frontlines out here. 4989 tried to get up, only to find his body impossibly heavy; he just had no strength left. Everything was numb or hurt. And yet he didn't feel afraid, emotionally he felt strangely composed. He was just so tired.

Perhaps this was it. They were made to die defending their world after all.

At that thought his mind turned to AC. 4989 gulped weakly, sorrow constricting his throat, as an unexpected, sudden onslaught of emotion jolted him awake momentarily. He hadn't even gotten to tell her.

Watch yourself, all right?

A hot tear escaped one of his eyes. "Sorry," he whispered shakily, his mouth dry. "I really messed up, huh?"

Was she safe? They had managed to contain the infection, so if none of her deliveries had taken her too close…please, be safe. Nothing else mattered.

The world around him turned from blurry to dim, until he closed his eyes, a last couple of tears squeezing through before they were completely shut. Idly he wondered if he'd open them again.

All sensations dulled and eventually vanished, even the excruciating pain fizzled out. Was it just him or had it gotten colder? If only he could have held her one last time. If only he'd kissed her up there in the marginating pool, just once.

Finally he could no longer fight it. As AC's image faded, he allowed darkness to overtake him and exhaled.

Three more days came and went and still no news of the battle. Sure there were some rumours that things were under control and that the fighting was coming to an end, but no sign of 4989 or any of the other three. AC was truly starting to fear the worst, despite her best efforts to push those desolate thoughts aside.

Along with thousands of other red blood cells, AC entered the right atrium of the heart, bracing herself for how cramped it would soon become. More and more cells entered the dimly lit, shrine-like room and within seconds AC found herself pressed up against those around her. Hopefully the doors would soon open on the other side; it was really getting warm.

"I tell you, it's all in ruins."

Suddenly the auburn haired erythrocyte heard something that made her strain her ears.

"Last I was up there it didn't look too bad."

"Yeah, last week maybe. I was up there just this morning; some areas look like wastelands now."

"Those white blood cells don't mess around, huh?"

"Especially those lymphocytes; there were whole battalions. Still, it seems like the neutrophil bore the brunt of the invasion." AC flinched at those words.

"What makes you say that?"

"Pus." Her insides twisted, her body turned cold; no, please not him. "Can't say how many, but there were piles."

"Horrible. Oh, the doors opened."

AC felt so numb that her legs refused to move and she was simply pushed along with the crowd; if it hadn't been so cramped she surely would have fallen. She was all but carried into the ventricle and afterwards even further into the pulmonary artery.

Only there did she finally find her strength again and AC left the crowd as soon as they entered the lungs. Ducking her head she slipped by, no one apparently noticing her in the twilight, especially as most of her fellow cells were looking through the windows to their right, admiring the view at the numerous alveoli outside. She headed for a quiet corner by the side of the road, where after making sure she was out of view, the auburn haired erythrocyte simply slumped down. AC embraced the box of carbon dioxide in her arms, trying to calm herself.

Of course she'd assumed that there were casualties, she'd seen neutrophils sacrifice themselves, but that apparently so many had died made her feel sick. And what if he was among those who had…fallen?

AC bit down on her lower lip, her fingers digging into the box. No, she shouldn't go there, there was no proof that he was. Fear could not get the better of her.

Her mind however seemed to be working against her, as it summoned images of purulence, created by the bodies of countless dead neutrophils. She'd only seen it once before in her life, but it was something the young erythrocyte would never forget. AC couldn't describe how frightening the possibility was to go up there and find him as nothing but an empty husk with hollow eyes...

Hastily she covered her mouth with one of her hands, her sight blurring.

No, there was no proof. AC forced herself to take several deep breaths, clearing her eyes as she did, hoping they hadn't reddened. She had to go up there and see for herself; right now she was probably imagining things worse than they actually were, given that all she knew was word of mouth from other easily freaked out erythrocytes.

AC returned to the bloodstream and soon entered a large hall, needing to narrow her eyes at first as it was well lit, bright compared to the corridor. From here more hallways and elevators led to the countless capillaries spanning the alveoli, all three hundred million of them.

As usual they were a few leucocytes around, in this case about a handful of neutrophils. Hoping against hope she checked on each she passed, on the off chance to see him, but of course he wasn't among them. And then…

"U-2048!" AC almost stumbled as she started to run, the sight of a familiar face giving her a jolt.

The neutrophil turned his head upon hearing his name, greeting her with a kind smile, when she reached him. "Ah, AC 4293. How have you been?"

He seemed calm, collected, which was more consoling than he could possibly imagine. AC was sure that if anything had happened to his childhood friends, he would have greeted her quite differently. Or maybe he didn't know anything either. Had he even participated in the battle with his arm? "Oh I'm fine, thanks," she replied, forcing a smile of her own on her lips, only to see him frown and so she quickly continued. "I heard about your arm. Everything healed up?"

"Good as new, kind of you to ask," 2048 replied lifting the previously injured limb.

The auburn haired erythrocyte took a deep breath. "Listen, I was just wondering if you've seen 4989?" She clutched her box again, speaking faster now, almost tripping over her own words, as if she was trying to get everything out at once. "He was called in over two weeks ago and then there was talk of a virus infection, though some said it was bacterial. I'm just worried that…" Suddenly he lifted his hand, interrupting her midsentence.

"Hey, take a deep breath," 2048 told her with a calm voice and a steady look, placing a hand on her shoulder, before he told her what she wanted to hear most. "He's alright." AC breathed out in relief, her body at a stroke feeling limp as all the tension she'd carried vanished in an instance. "We were indeed called in to repel a virus invasion, but during the battle some bacteria exploited our weakened defences to make their move."

Secondary Infection

An additional infection to the still on-going, initial one (primary infection), by a different microbial agent of exogenous (external) or endogenous (internal) origin. In some instance such a case is also referred to as a superinfection.

"Both?" No wonder this battle had taken so long.

The straight haired neutrophil nodded. "Yeah; it took us about a week to get control over the situation and a week more to fully repel the invaders; the fighting actually only ended earlier today. 4989 did get injured," he squeezed her shoulder gently when she flinched at that. "But don't worry, he's been taken care off and was ordered to rest, so now he's sleeping it off under surveillance just to be safe. Trust me, he wasn't too happy either, but he'll be back in no time."

"So he's fine?" He'd already said it, but she needed to hear it again. Hopefully he didn't notice her eyes welling up.

"A little annoyed and tired, but yes, he's alright," 2048 confirmed and winked. "And I'm sure he'll be glad to know that you didn't get caught in the crossfire."

"Thank goodness." He couldn't know how much that meant to her. But she still wanted to see her friend. Feeling her cheeks warming, AC asked another question. "Ahem, you don't happen to know where he's recovering?"

…

2048 had known, including the room-number, and so as soon as time permitted it AC went to one of the immune cell infirmaries across the body. Aside from the bone marrow they could be found at the same locations where neutrophils also received new clothes and equipment, like spleen and liver.

It was a busy place, with leucocytes almost constantly coming and going, though a few seemed curious as to why a lone erythrocyte was coming to this facility. None stopped or even addressed her though, as she made sure to walk purposefully, like she knew exactly where she was going.

In truth, once she entered the clean, white corridors she turned to a macrophage and asked her for direction, which the motherly smiling white blood cell gave without hesitation. She didn't even seem surprised or puzzled to see a red blood cell, or maybe she just didn't show it.

Finally the auburn haired erythrocyte found the right room, yet hesitated before entering. From what she'd gathered his injuries weren't too bad, still she braced herself as she put her hand on the silver doorknob and quietly opened the door.

Beyond she found a room painted in the same white as rest of the building, though the only light illuminating it fell through three windows, the view blocked by thin curtains. As far as furniture was concerned there were only a handful of beds and while two showed signs that they had recently been used, only one was currently occupied, the one furthest away from the door.

AC stepped closer, trying not to make a sound, as the person was clearly sleeping or at least resting. She couldn't express how much it lightened her haemoglobin to see that it was indeed 4989, fast asleep, his uniform missing and his already fluffy hair a mess, but it was him.

And he looked so adorable. 4989 was lying on his right side, facing her, but apparently he didn't quite know how pillows worked, as his arms were hugging the small one he'd been provided with, leaving his cheek to lie on one of the corners. It was admittedly strange at first to see him without the uniform, a short-sleeved shirt revealing most of his well-toned arms, which she couldn't help but noticed featured a few scars, though barely visible on his already pale skin.

More troubling however were the contours of bandages beneath his shirt, apparently covering his left shoulder all the way to his neck and the entire chest. Maybe it was her lack of experience in these matters, but this just didn't look as minor as 2048 had claimed.

"Didn't I tell you to watch yourself, you idiot?" she whispered, rubbing one of her eyes when her vision got a little blurry, yet she couldn't help but smile as well as a sense of relief once more washed through her. Injured or not, he was still alive, he was here.

As far as she could see he wasn't injured anywhere else, though with his legs covered by the blanket it was difficult to say. AC wanted nothing more than to hug him, talk to him, but she didn't want to disturb him. After everything he'd been through, from the fighting itself, to his injuries and losing fellow leucocytes, he deserved a good long rest. Waking him would only hinder his recovery.

For a while she stood at his bedside, reassuring herself that everything would be fine, before she reluctantly decided to leave again. There was nothing she could do for him here and if she lingered longer, AC feared that she would only wake him after all. Before departing however she placed a small paper bag in the table beside his bed. He'd probably be hungry when he woke up and after every time he'd brought her something it was only fair to return the favour.

The first thing he felt was the mattress beneath him and something soft in his arms. Slightly confused he squeezed it, slowly realising that it was his pillow. Oh right, he was in the infirmary.

Gradually 4989 opened his eyes, allowing them to adjust to the light in his room, far too bright for his liking after having slept for some time. It was just as bad as the last time he'd awoken. He remembered his friends having been there to check on him, but struggled to remember any details, as if it had been but a dream.

He recalled being confused about being still alive and in having been in quite a bit of pain. Relieved 4989 realised that his injuries actually felt a lot better this time around; sure he still felt them, yet there wasn't pain, more a tickle across his chest and shoulder.

Additionally this time his head felt clearer, he actually felt awake, and as he let his eyes roam he saw that on his bedside table now stood a little paper bag, a faint, yet sweet scent emanating from it. What quickly caught his eyes however was the small note sticking to it; Get Well Soon, he read in large characters and squeezed into a corner AC.

Within a second 4989 sat as straight as a pole in his bed, flinching when a sharp pain rushed across his chest where the bacterium had struck him. Okay apparently his wounds had still not completely healed yet, but that didn't matter right now. She'd been here, she'd checked on him, she…

"Glad you are finally awake."

Startled 4989 turned around, having not expected someone to be here. When he saw who it was, a smile spread across his face. "Sensei!" he exclaimed brightly, but nonetheless puzzled. "What are you doing here?"

"Can't I visit one of my injured students?" 1110 asked, smiling as well, having made himself comfortable on a chair at the other side of the bed.

"Of course, I'm just surprised. How long have you been sitting here?"

"Just a few minutes, my break's only just begun," the older neutrophil explained. "Last time I checked on you, you were still sleeping, but I saw your 'friend' AC 4293 on her way out."

4989 felt his cheeks warm, when he noticed his teacher's tone. "It really isn't what you think," he mumbled, yet glancing over to the note again.

Out of the corner of his eye, he saw 1110 lean forward in his chair. "Perhaps, but you want it to be." Was he that easy to read? "4989, I raised you; don't think you can hide something like that from me."

The fluffy haired neutrophil's shoulders sank. "If you think it's a mistake, I already know a Memory-T Cell, who chewed 1146 out multiple times. I'm sure I'll too get a turn, so you needn't bother." It was something he expected, but not looked forward to.

His old teacher however shook his head. "I'm not going to advice you one way or the other. Just like with 1146, as long as you are happy and fulfil your duties I don't think I need to interfere," he smiled again. "And she seems to have taken quite a liking to you as well."

Grinning shyly 4989 rubbed the back of his head. "I guess I'm a lucky neutrophil."

For a moment 1110 seemed to be contemplating. "She seems to be a nice girl," he eventually noted, before giving his former student a rather stern look. "So treat her well; I'll hear about it if you don't."

4989 gulped. "Yes, sensei." It had been some time, but he'd learned to fear that look, back when he'd been a myelocyte, and as a troublemaker he'd gotten it a lot. That one time he'd almost hit 1110 with the makeshift arrow…

Clearly satisfied with his student's reaction the older neutrophil's features relaxed again. "Now, I actually came here because I had some good news. You've made a request to the hematopoietic stem cells, about meeting a class of erythroblasts."

How many weeks had it been? Frankly he'd lost track of time. "I just want to introduce them us white blood cells. I know the macrophages usually do that, but I feel like the children are getting the wrong impression, especially of us neutrophils, given how they react to us once they're erythrocytes. It's one thing if they are disgusted by the carnage, fair enough, but they shouldn't be afraid or think we're just savage killers." He looked to 1110, hoping he would agree.

"We're cursed with an abundance of negative stereotypes, true," his former mentor eventually agreed and studied 4989 with a pensive expression. "You think you can change that?"

"Maybe. It's worth a shot, so I want to try." He was determined, after his visit to the bone marrow with AC more so than ever.

1110 nodded. "Well, the hematopoietic stem cells have approved your request. They've asked me to tell you that you can discuss the scheduling with the resident head-macrophage as soon as you've recovered."

"Yes!" 4989 cheered, clenching his fists triumphantly. One step closer. Hopefully the macrophages wouldn't be offended.

Observing him the older neutrophil tilted his head, giving him a curious look. "Ever thought about going into teaching one day?"

"A troublemaker like me?" 4989 laughed. "Not exactly the kind of role-model they would want for the job." Besides, he wouldn't get to see AC as often, or be able to protect her.

"Probably not," 1110 conceded. "Which reminds me…you remember the myelocytes you saved a few weeks ago?"

"Of course, why?"

"Well, naturally they've found out where I was going and who I'm visiting," he explained. "Aside from wishing you a speedy recovery, they would also like to thank you again. They asked if they could visit, but I wanted to run it by you first, makes sure it's alright."

"Absolutely." Their request came as a surprise, but delighted him nonetheless. "How have they been?"

His old teacher leaned back in his chair. "Well behaved; encountering a real germ seems to have left quite an impression. They've been more diligent with their studies too."

4989 chuckled. "Reminds me of 1146, although he always took his training seriously." Still, following his encounter with a Pseudomonas, U-1146 had become even more dedicated to his training, incidentally spurring his friends on in the process.

Before 1110 could reply, the door was cautiously opened. "Oh, I didn't expect another visitor," 2048 admitted smiling as he entered. "Good to see you again, sensei."

"You too, 2048," the older neutrophil replied in kind.

Then his friend's eyes wandered to 4989 and the smile became an amused grin. "Ah, I see AC found her way here."

"You met her?" 4989 all but exclaimed. He was desperate to know how she'd been; had she managed to stay away from the upper respiratory tract, or had she encountered a stray germ that had made it through their line of defence? What if she'd gotten hurt while he'd been away and unconscious?

Thankfully 2048 didn't keep him waiting. "At the lungs. Frankly she seemed a bit agitated to me, probably because she hadn't heard from you all this time, so I figured I should tell her something."

Now the fluffy haired neutrophil was worried for a different reason. "How much exactly did you tell her?"

"Relax, hardly anything, just enough to ease her mind." 4989 breathed a sigh of relief as his friend continued, now standing by his bedside. "I downplayed your injuries as much as possible and that's about it. Given how worried she already was, I didn't think describing how we found you all torn up and unconscious, would have been a good idea."

"Thanks." The first thing he had to do once he got out was to find her, let her know he was okay. That and apologize for not keeping his promise; he shouldn't have gotten separated during the fighting, such a band cell mistake.

2048 shrugged, pulling closer a chair for himself and sat down beside their former teacher. "Don't mention it. But you can tell her yourself; I'm sure she'll ask for details."

4989 sighed. "Guess you're right; that's not gonna be a fun conversation. Still, how was she? She didn't get hurt?"

"Physically she was perfectly fine; if she's been to the upper respiratory tract, she's gotten away without a scratch."

Closing his eyes 4989 sank back down, head landing on the mattress, as the pillow was still under his arm. "Thank goodness."

"But as I've said, she's a bit stressed out and with all the rumours going that's hardly surprising," his friend noted.

Things had looked bad even to the immune cells, which probably meant that it must have appeared even worse to all the other cells. "I wish I could give her a transceiver," the fluffy haired neutrophil lamented. "It would make things so much easier."

"You really ought to tell her," 2048 remarked after a moment of silence. "At this point you're worse than 1146."

Sitting back up, 4989 brushed through his hair, yet averted his now warm feeling face. "I was gonna, but then I got the call, which kinda ruined the moment," he mumbled.

From the corner of his eye he saw his friend slowly nod. "Point taken. Still, unless you want us to intervene eventually, you have to make a move."

Suddenly 1110 chuckled, looking content. "I see you're all still supporting each other."

"Of course; can't keep your eyes off this one," 2048 joked, pointing at his still flushed friend, earning himself a glare.

"I almost died," 4989 reminded him. "How about some moral support?"

"Got that covered," the other neutrophil claimed and pulled a familiar looking envelope out of his jacket. "I got this from your locker."

Oh, no the photos. "Did you look at them?" They weren't exactly embarrassing, but they still showed some rather personal moments between him and AC.

2048 placed the envelope on his bed. "All three of us looked at them."

Covering his face with both hands 4989 groaned. "I need to get a new lock."

In a quiet arteriole AC was pushing her cart along the almost empty road, apartment buildings to her right and a little park to her left. Some cells were playing badminton there, she heard them shouting and laughing, while a few platelets cheered them on.

The erythrocyte stopped for a moment to watch the match; she'd never played herself, though wished to try it out sometime. Maybe after delivering the oxygen…AC looked at the address again and deflated a little. The detour would be too great to be justifiable. Maybe another time.

A little disappointed AC was about to continue on her way, when two arms wrapped themselves around her, making her jump for just a moment, until a very familiar voice addressed her. "Hi, there."

Warmth spread through her chest. He was back! Oh, how she'd missed hearing his voice. AC wanted nothing more than to turn around and hug him, but his arms were trapping hers, while her back was being pressed again his chest. Finding herself thusly immobilized, she instead leaned back into his embrace, managing to at least turn a hand far enough so she could place it on his arm.

"You're back," AC managed to breathe, being somewhat choked up.

"Sorry I took so long," he apologized sheepishly, almost mumbling those words into her beret.

She gulped, forcing her voice to remain steady. "You had me worried there." Part of her could have cried tears of joy, yet another part wanted to scold him for being careless and getting himself injured so badly. But she'd never been in battle, much less one lasting two weeks; who was she to judge? Still, she had asked him to watch himself.

"Sorry," he repeated, almost as if he'd guessed her thoughts. 4989 loosened his embrace, just enough for her to turn around and throw her arms around his neck. Just to be able to hold him again…she'd missed him so much.

"How are you're wounds? 2048 didn't say much," AC asked, suddenly thinking of the bandages she'd seen, hoping she didn't aggravate any of his injuries.

His arms remained around her however and 4989 hadn't shown any sign of pain so far. "Completely healed," the fluffy haired neutrophil assured her. "Still got some minor bruises, but I don't really feel them anymore. Maybe there will be a new scar or two, though it's a bit too early to say. Overall I'm just feeling a bit tired after everything. What about you? Did you have to go near the battlefield?"

She shook her head, as well as she could with it still leaning against his shoulder. "No; I had a delivery near the ear, but that was the closest I got. I did hear a bunch of rumours and a few reports from other erythrocytes, which didn't exactly put my mind at ease."

He squeezed her a little tighter, her beret shifting, as he apparently pressed his cheek against it. "I didn't mean to worry you," he murmured, sounding rather conscious-stricken.

But AC didn't want him to have a guilty conscience; the invasion was hardly his fault. "Hey, you're always gonna be out there fighting," she said, clutching at his uniform. "Of course I'll worry, but as long as you come back it'll be fine. So watch yourself, okay?" She couldn't, as much as she wanted to, so she would have to learn how to deal with this sort of thing in the future.

His head move, perhaps he tried to nod. "Promise."

For a while they stood there, embracing each other without saying a word. "You know, you're going to have to let me go eventually," AC noted, despite her own reluctance to move.

4989 hummed. "Afraid so," he finally agreed, not sounding like he wanted to either; after everything he'd probably gone through AC wasn't exactly surprised. He kept holding her for a few more moments before she felt him lift his head. "Hey, care to join me on a little project?"

"What do you have in mind?" she asked curiously, trying to look up, though unable to see more than his chin and jawline. He was already up to something again as it seemed, which amused and relieved her at the same time.

He shrugged. "Oh, just something we talked about a while ago. Still, I wanted to go over it with you first. Got time?"

"Still have to finish this delivery, but afterwards…"

"Alright." Suddenly he let go, snatching her beret as he jumped away and escaped her grasp. "Let's speed things up then."

AC's hand flew to her head as she saw him wave her red headgear, only feeling hair. "Hey!" He ran and without hesitation she went after him, spotting his wide grin when he glanced over his shoulder, making sure she was following. "Give it back!" And yet she couldn't help but laugh as she gave chase.

…

A little that day AC found herself waiting in line for tea, her beret retrieved and back on her head. 4989 meanwhile was waiting on a bench just around the corner with her cart. On the way he'd confessed that he was more than just a bit tired and actually felt quite drained after the two weeks of fighting and his recovery. Upon taking her first good look at him, she'd seen the rings around his eyes, which he'd tried to mask with his usual smile and by pulling his cap down a bit further than usual.

For a moment AC had been meaning to ask why he was here and not using the time to find himself a quiet marginating pool and get some more much needed sleep. But she already knew why; he was here because of her. He'd probably searched for her.

AC felt bad for keeping him up, but at the same time the thought made her haemoglobin flutter. It certainly gave further credence to what pretty much everyone else was already assuming about them both. And yet she herself was still uncertain concerning her own feelings; even if she knew what signs to look for in others, what was it supposed to feel like?

She needed advice, someone she could talk to about this, who had gone through something similar. Frankly among the very few erythrocytes AC knew to be in a relationship, there was only one; AE 3803. Not only had she stumbled into hers and suddenly came to the realisation that she was in love, at least according to the redhead's own account, but she was with a neutrophil. Certainly she would be able to help remove these ambiguities.

After all, the last thing AC wanted was to hurt 4989 and as much as she cared for him, the thought of taking the next step so to speak made her uneasy. She simply didn't feel quite…ready. Suddenly AD's and CT's words were ringing in her mind, making her chew on her lower lip. Was she actually letting herself be influenced by what they'd said? Sure, she appreciated their concern, but they were wrong about 4989.

"I can't help but wonder how you can be comfortable around someone who has so much blood on his hands?"

But she was. She was probably more comfortable around him than anyone else. However if he made a move, what if she suddenly found that she didn't return his feelings as strongly or wasn't comfortable with intimate gestures beyond hugs? What overall would it change between them?

AC tugged at some of the wild strands of hair framing her face and sighed. It didn't help that she might have encouraged him. She had pecked him twice and though it had been a spontaneous gesture of gratitude on her part, she admittedly had never thanked anyone else like that. It wasn't fair to him. She really needed to sort this out, before she did or said something she would regret.

Not right now however. Getting her two cups of fresh, steaming tea from the kiosk, AC returned straight to the bench she'd left her friend. He was finally back after all, instead of worrying and overthinking she should just enjoy the moment and make the most of their break together.

The auburn haired erythrocyte turned around the corner into the small street and stopped midstride, a gentle smile on her lips. 4989 really must have been exhausted.

He'd slumped down on the bench, now lying across it, with only his feet dangling off the edge. As he was lying on his side, facing her, she could see that he wasn't just dozing but actually asleep, his body completely relaxed, while one of the many trees lining the road casted a large shadow over the neutrophil.

For a moment AC considered waking him, but quickly decided against it and put the tea down. As quietly as possible she took off her jacket and folded it neatly into a square, making sure the zip was hidden and could not be felt. Very gently she then lifted 4989's head, just enough to slip the jacket under his cheek. Someone had to teach him how to use a pillow.

To her relief the fluffy haired neutrophil didn't wake up, his features merely twitched once before becoming utterly relaxed again. Satisfied that he was resting a bit more comfortably, AC sat down on the cool ground, so that her head was next to his and her back rested against the bench.

She looked over her shoulder, checking if he really was still sleeping, before reaching for her tea. He really did look cute like this, though she wondered about setting his cap aside, as it had already almost slipped off on its own, though ultimately deciding against it as to not risk waking him.

Instead AC relaxed and took a sip of her still steaming tea; she'd get him a new one once he woke up.

As she drank she could hear him breath calm and evenly, actually finding herself relishing the sound. It was strangely reassuring after those three long weeks. They were spending time together again, things were back to normal; that was better than any fireworks. Frankly, she wouldn't change this for anything in the world.

Chapter Text

Mycosis

Part 1

Things had quickly gone back to normal after 4989's return, though during the first few days the neutrophil had still been comparatively subdued, tiring easily even when they were just walking. AC had been very understanding, the image of him covered in bandages still fresh in her memory, so the two had spent most of their time together just sitting idle and talking.

Today he'd brought her to a calm little place in the large intestine, more specifically one of its countless crypts, a place red blood cells admittedly shouldn't be as they were currently just outside the blood vessel.

Crypts of Lieberkühn

Tubular pits, further increasing the surface area of the intestine for optimal nutrient absorption as well as serving as glands for secretion of enzymes.

This however was one of the best places to encounter good bacteria. The colon harboured the majority of them, vital little and sometimes large helpers the body could not properly function without.

Along what AC could best describe as a coastline piers had been built by the local cells of the intestinal wall, who maintained the epithelium and oversaw the absorption of nutrients as well as water, which reached far into the waters. The two circulating cell had made themselves comfortable on one of those piers, with more than a dozen of the small oval lactic acid bacteria surrounding them, partially because 4989 had brought biscuits with him. Where he'd gotten them from remained a mystery to her, as he'd only replied with a cheeky "trade secret".

AC had dropped the subject with a shrug and she surely wasn't going to complain about the results. One of the little black and white germs was currently sitting in her hands cooing as she petted it. "They're adorable. How did you learn of this place?"

"Well, that day U-1146 was escorting a normal cell through the entire gastrointestinal tract, helping him return some of these stray lactic acid bacteria," 4989 explained, giving away another biscuit, which was immediately fought over by several tiny flippers.

"Did you join them on their little tour?"

He shook his head. "Nah, I was helping with a clean-up at the stomach, until I got a call about some obligate pathogenic bacteria here in the large intestine. I teamed up with a few others and when we arrived at the scene it turned out it was the very cell 1146 had accompanied we got to save."

"Where was 1146?"

"Dealing with yet another threat…oh, I forgot to mention the flu virus that had gotten in as well and Dendritic Cell activating everyone even remotely close to the intestine." He sighed. "Damn that was one busy day."

A grin spread across the erythrocyte's lips. "Activated, huh?"

She saw his eyes widen before he turned to her. "Don't get any ideas; I ate the picture just to be safe."

AC shrugged. "I'm sure Dendritic Cell has a copy."

"Please don't ask him for it," he begged her.

Unfortunately for him that only made her more curious, which frankly he should have predicted. "Why? What was on it?"

His cheeks turned a pale pink. "Oh, you know, something embarrassing from my childhood," 4989 said.

"I was guessing that much," she laughed amused. "Come on; how about some details?"

"Weren't we talking about cute little bacteria?" the neutrophil noted evasively, giving her a pleading look.

"Alright. So you rescued the cell."

"Yes." His body visibly relaxed and his smile returned. "Well, we were still outnumbered, as some opportunistic bacteria had joined the enemy's ranks, and just as the real fight was about to start, suddenly a large force of good bacteria literally crashed in through a wall. Turned out one of the little guys the cell had brought with him had escaped and alerted his friends." He gave the little ones sitting by his side the last biscuits they'd been eyeing all this time. "They really helped us out that day. Ever since I've been coming here once in a while, see how they are doing."

"Oh, you brave little guys saved our neutrophils," the auburn haired erythrocyte praised the small bacterium in her hands, tickling it affectionately.

"Assisted," 4989 insisted.

Giggling, AC nudged him gently with her elbow. "Just teasing."

For a while to two sat in silence, watching and petting the bacteria, enjoying the moment of peace and quiet. Things after all could drastically change within moments, especially here. But today they were lucky and his receptor stayed down.

"So about those driving lessons…"

AC shook her head, but with a smile on her lips. "Still haven't gotten those out of your head I see."

"Well, there is a tiny bit of room for improvement," he admitted, quite aware that his usual method of stopping with the cart involved crashing into something. "I mean should we really risk having me practise on my own?" the neutrophil jokingly added.

"Nyu, nyu," the bacterium in AC's hands chirped.

The neutrophil gave her the biggest grin. "See, he agrees."

"Nyuuu!"

"I must say he is quite persuasive," she conceded.

"I know…hey!" 4989 exclaimed with feigned indignation.

AC chuckled at his reaction. "I'll think about it, okay?" she promised. "In any case we should wait until you've made a full recovery. No offense, but you're already quite accident-prone with the cart as it is."

The neutrophil twisted his mouth, but couldn't exactly argue with her assessment. "Fair enough."

It was in that moment that several larger bacteria broke through to the surface of the intestinal waters. The penguin-like prokaryotes jumped up, only to crash back into the waves, while a bunch of smaller bacteria rode the billows they created. Suddenly one leaped close to the coastline, its shadow touching the pier.

"Watch out!"

Before AC could react, 4989 had thrown himself at her, just as the billow hit them. Bracing herself the erythrocyte closed her eyes, curling into a ball, haemoglobin twisting in fear. The wound at the foot, FP getting washed out of the body...

The images flashed before her eyes, however his time there was an arm around her, holding her tightly and the wave subsided just as quickly as it had come.

"You're okay?" she heard 4989 ask, feeling him let go of her.

AC spat out some water as she rubbed her eyes with one of her hands. "I think we need more than a towel," she eventually noted between two coughs, hoping he wouldn't notice her trembling or at least attribute it to the cold and she was feeling cool, being completely drenched.

Apparently it worked, as 4989 smiled and pulled her back on her feet, rubbing her arms in an effort to warm her up. "Come, there's a wash station a few blood vessels from here."

Cleaning up the intestinal residue was not a peaceful affair. It was a battle. It was only the two of them at the station, a wall between them and the bloodstream, both with a hose in hand, showerheads raised. Just like back at the ear, the first time he'd brought her to one of these facilities. This time however they remained alone, though that didn't mean that the fighting was any less fierce.

4989 was blind the entire time, not feeling the cold despite being drenched, almost unable to hear even his own laughter over the sound of the rushing water. But whenever he managed to open his eyes, even if just a tiny bit, he saw her smiling or laughing as well, which frankly was enough to make him feel warm inside.

Still, this was a stalemate and that would not do.

The fluffy haired neutrophil looked around the station and saw that AC was standing close to the pool that framed the room on two sides. His smile shifted into a mischievous grin.

Showerhead kept in front he suddenly charged towards AC, who due to her mostly closed eyes didn't realise what was happening. In the last moment he dropped the hose and wrapped his arms around her, hearing the erythrocyte yelp in surprise. Somewhere behind them the two showerheads fell to the floor with a loud, echoing sound, just as 4989 leaped into the pool, dragging AC with him.

The water was cool and rushed loudly in his ears, literally drowning out every other sound for a moment. Then his foot touched the ground and he pushed himself off, getting both their heads back above the surface.

Immediately AC gasped for air and to his surprise clung desperately to his uniform. "4989! I can't swim!" she coughed, eyes closed.

Not the reaction he'd expected, but it was kind of funny. "AC? Put your feet down."

She opened her eyes and he felt AC straighten herself, until her toes touched the ground. "Huh?" AC stood in front of him, looking surprised as she realised that the water didn't even go up to her shoulders, which made him bite his own lower lip in an effort to stifle a snicker. The erythrocyte noticed that and gave him a glare. "Don't you dare laugh."

"Sorry." He couldn't hold back anymore and burst into laughter.

"Oh, you…!" AC slapped his chest, now no longer holding on, but that did nothing to stop him from guffawing; quite the opposite actually. Eventually she just huffed and shoved him, before getting out of the pool.

As 4898 calmed down, wiping tears from his eyes, AC got herself a much needed towel. She started drying her hair with it, her braid having completely unwound during their fight, both their hats currently lying around on the floor. When the silence between them continued on the neutrophil suddenly began to worry. Had he gone too far with tackling her into the water? She was still a none-immune cell after all, maybe he'd been too rough.

He left the pool as well and came up behind her, wrapping another soft towel around her, hoping to help her warm up, ignoring for a moment that he too was shivering. "Hey? You're alright?" the fluffy haired neutrophil asked hesitantly, studying her expression for any clues.

He seemed to have roused her from some deep thought, as she briefly looked puzzled. "What? Oh yes, I'm just…just not a fan of water, I…I mean being in it, you know."

Now it was his turn to be confused. Why wouldn't she like water? He never would have guessed after the fun they'd had at the wash station near the ear. Then it dawned on the neutrophil. The next time he'd seen her had only been days later, after…oh no. No, no, no, no, no. "I'm so sorry, I hadn't considered. I'm such an idiot," 4989 groaned, burying his face in his hands. The foot; her friend had been swept away and she almost along with him. How could that have slipped his mind?

"It's fine, Hachikyu-kun," she softly assured him.

"It really isn't though," the fluffy haired immune cell protested, before gingerly taking her hands, bowing his head. "Again I'm so sorry. I really didn't mean to…"

But AC squeezed his hands, interrupting him. "I know, I know. So, let us forget about it and just not do that again, okay?"

4989 breathed a sigh of relief. "Absolutely. Still, is there anything I can do to make it up to you?"

"Like what?"

"I don't know," he admitted with a shrug. "How about fixing your hair for starters?" For emphasis he playfully tugged at two of the loose strands falling over her shoulders.

Much to his delight she chuckled, making him smile again, glad that everything was still alright between them. "Okay. But let's get some tea first; I don't know about you, but I need something to warm up."

The two blood cells returned to the lungs, slowly drying with each step. Their clothes were still clinging to their membranes though and a few other cells looked curiously at them, but that was nothing new.

At the lungs 4989 went ahead to the little shops and booths, while AC got a new delivery of oxygen and by the time she joined him he was waiting by the side of the road. He stood close to the tree that had become one of their usual meeting spots, in each hand a mug of tea with steam still rising from them.

"Look who I found hiding in on my cart," the erythrocyte greeted him and lifted her beret. When taking the carbon dioxide box, AC had found one of the little lactic acid bacteria in it, looking at her in wonder, likely confused as to where it was. She assumed it had been swept to her cart, when the wave had hit them and had then sought shelter.

Now it sat in her hand and lifted its tiny flippers as if to greet the white blood cell as well. "Nyuuu."

"A little stowaway, huh?" 4989 quipped, poking the little germ's cheek with an outstretched finger, careful not to let the hot mug touch it. "Guess we should return you."

"I have a delivery to the left shoulder."

Her friend merely shrugged. "Then I bring it back and afterwards meet you here again; shouldn't take too long."

She loved that idea and smiled, though she would have preferred to go with him. "Alright, sounds like a plan."

"Good, but first things first; I promised to fix your hair." With that he gestured to a place on the lawn, right next to the tree. "If you would sit down right here."

AC chuckled and did as he ask, parking her cart a few steps away at the side of the road, yet he little lactic acid bacterium remained in her hand. Meanwhile 4989 sat down behind her, handing her a mug and setting down his own before he took off her beret, so he could start to work on her braid. For the next few minutes she felt him move and tug at her hair, AC admittedly being quite comfortable, nipping at her tea every now and then.

Eventually she noticed that he had slowed down, pausing every now and then for a moment. "What are you doing?" she asked after several more minutes, wondering what he was up to. Given that his fingers were now going up and down along the braid he had to have finished.

He replied with a snicker. "Be patient; I'm almost done," the fluffy haired neutrophil assured her.

"You've been working on my braid for a while now," she explained. "Don't blame me for being curious."

"I'm not, it just…fiddly work you know."

"No I don't, that's the point." AC laughed, though not even thinking about stopping him; now she just wanted to see the results. She turned back to the little bacterium in her hand. "Do you know what he's doing?"

The oval shaped prokaryote covered its mouth with its flippers as if to shush itself. "Nyuuu," it merely chirped.

"Hang on," 4989 told her and she felt a final tug. "There." An arm came around and he was holding something in his hand.

"A flower?" It was small and blue, looking somewhat like a dandelion; she'd actually seen quite a few of them around the lungs recently. "Thank you." AC took it and held it up to her nose, but found that it had no scent.

"You like it?"

She turned her head. "It's pretty, but what does it have to do…"

AC didn't get to finish her sentence, as he was holding her braid, presenting it to her with a broad smile on his face. "Ta-da!"

She laughed again. "Along the entire braid?" There were flowers everywhere and she was pretty sure he'd only given her the one, because he'd run out of places to put them.

"Yep." He proclaimed proudly. "You like it?"

"Yes, it's beautiful," AC told him; frankly she'd never done anything like this with her hair. "Thank you."

"You're welcome."

Taking the braid she admired his handiwork more closely, her fingers brushing over the flowers. "I should have you make my hair more often."

4989 gave her a mischievous grin, making her wonder for a moment if she would come to regret that remark someday. "At your own peril."

"Surprise me." Worst case scenario she had to fix her hair afterwards. More importantly it meant more time they could spend together.

"AC, 4989!" Both cells looked up when they suddenly heard someone shout their names and the erythrocyte spotted AE 3803, who all but ran over to them, 1146 following at a leisurely pace. "What happened to you guys?" the redhead asked, seeing as their clothes weren't yet completely dry.

"Oh, we had a little accident at the intestine, so were catching our breaths before the next circulation," AC explained.

"And the little guy?" 1146 asked, nodding towards the lactic acid bacteria still sitting in one of AC's hands.

"Yeah, it kinda hid on her cart. Gotta get it back too," the fluffy haired neutrophil explained.

"Well, I need some glucose first. Can you wait for me here?" AC's last meal had been some time before they'd gone to see the good bacteria and by now she was famished.

AE nodded with a cheerful smile. "No problem."

"Great." She handed 4989 the bacterium. "I'll be back in a second."

…

4989 watched AC disappear in the crowd, trying not to feel a little disappointed. A part of him had hoped for another peck as a thank you just like at the brain, but that had probably been a bit presuming.

"So, did you tell her?" AE asked excitedly almost as soon as AC was out of earshot.

"What?" The neutrophil needed a moment to realise what she meant. "Oh, no! No."

His reply seemed to surprise her. "Why?"

"Not you too." It was bad enough that his friends didn't get off his back about it.

"I just thought…you know the flowers…," the redhead mumbled sheepishly.

4989 sighed and rubbed the back of his head. "That was really more a spontaneous idea. I'm waiting for the right moment to tell her."

"And when will that be?" 1146 asked, an eyebrow raised.

"When I find another location as breath-taking as the retina or the neuron-fireworks." He saw his friend's frown deepen. "I'm working on it," the fluffy haired neutrophil promised.

"Don't you think that might be a bit risky?"

4989's hand wandered to the scar along his shoulder and chest. "You think I might never get the chance, if I wait too long."

His friend hesitated. "It's possible."

Of course he'd considered that, but truthfully he was still more afraid of ruining what they did have.

"I can see why you'd like to tell her at some special location, but it's not what matters most," AE explained, breaking the silence. "If I think back to that day, it's not the light falling into the eye I think about, as beautiful as it was."

"Are you afraid to tell her?" 1146 inquired, probably recalling his own girlfriend's reluctance to confess her feelings.

"No! Yes?...Maybe?" 4989 sighed, shoulders sagging; it was difficult to describe. "Look, this wasn't exactly planned and I don't want to mess things up between us by pushing too far. If she only wants to be friends it could make things really awkward between us."

"I could ask her."

Both neutrophil looked at AE, 4989 surprised by her suggestion. "Huh?"

"I ask AC how much she likes you and then you don't have to worry about it anymore, right?"

The fluffy haired neutrophil turned back to his friend. "Your girlfriend is adorable," he told him and then smiled at AE. "Alright, but don't tell her about me; I want to be the one to tell her." But this could actually work and fix his dilemma; if he hadn't been holding the little bacterium in one of his hands he would have hugged her.

The redhead nodded. "Right."

"AC's coming back." 1146 warned them and 4989 felt his mitochondria jump.

She was quickly jogging through the crowd to re-join the group, a bag in hand, which probably contained some backed goods. "Thanks for waiting."

"No problem," the fluffy haired neutrophil assured her, his mind still lingering on his friend's advice. Yeah, he did want to tell her, despite any excuses he made.

"Now; my delivery is to the left shoulder at the collarbone, so I guess we split up?"

"Oh, mine's to the left triceps," AE told her brightly. "We can go together."

"Of course."

"Then we'll just return this little guy," 1146 decided, placing a hand on his friend's shoulder.

"Nyuuu!"

"Meet back here for the next circulation?" 4989 asked, hoping they could stick to the original plan.

"Sure," AC confirmed.

His fellow neutrophil nodded. "Alright, you two stay safe." 1146 then leaned in to place a kiss on his girlfriend's cheek and 4989 glanced over to AC, who he noticed was tugging at one of the strands of her auburn hair. Strange; usually she only did that when she was nervous or abashed.

Waving one last time the four cells split up, 4989 unable to keep himself from grinning seeing those blue flowers in AC's braid, making her stick out among her peers.

Not long after their departure from the lungs AC and AE found themselves travelling up from the heart, talking about places and organs of the body they had most recently visited. Despite being around as old as the auburn haired erythrocyte, AE was still in awe of pretty much everything she saw for the first time. Every cell in the body worked with a great deal of enthusiasm, but hers was something else, even a bit infection for the lack of a better work.

"And then I've been to the gallbladder, which at the time was filled with this viscous, green liquid and it had that crazy serpentine coastline. They had put up signs everywhere, warning not to swim in or even touch the liquid."

"I'm not sure how much those liver enzymes could do to us, but I suppose you could always get dragged out into the duodenum if you're unlucky." The idea of being on the wrong side of the mucosa was actually terrifying; there was no coming back from that. Same might have happened earlier today, if 4989 hadn't covered her.

AE apparently had imagined something very similar, as she visibly shuddered. "I wasn't going to find out, but it took me so long to find my way out again. There were just so many folds," she said, blushing a little. "So, what have you been up to?"

AC shrugged. "Oh, not much, aside from visiting the good bacteria today."

Her red-haired friend's face lit up. "1146 took me to see them as well; they are so adorable, even the bigger ones. It was one of the first things we did after we got together," she confessed, now truly flushed, making AC chuckle.

Moments later however the redhead got distracted by someone ahead of them in the crowd. "Oh, senpai!"

One erythrocyte turned around and AC recognized her as AA 5100. She had only meet her a few times, usually in AE 3803's company, a level-headed woman, who was truly like a big sister to the younger red blood cell. "AE, AC; good to see you two again," she greeted them both, having stopped so they could catch up.

"Likewise," AC replied.

"What happened to your hair?"

"Oh, I had to visit the wash station earlier today and U-4989 offered to fix my hair afterwards. He took a few creative liberties."

This earned her a mischievous grin from the older erythrocyte. "Usually boyfriends will just give you the flowers," AA noted.

Now it were AC's cheeks which turned red; she could feel the heat radiating from them. "We're not…he isn't..." Even to herself she sounded horribly defensive.

Clearly the other erythrocyte wasn't convinced either. "The twenty or so blossoms in your braid beg to differ."

"It's complicated," the auburn haired cell said, still hoping to avoid the subject.

The smile was exchanged for a questioning frown. "Are you sure?"

"I…," AC sighed. "I'm just overthinking things, I'm sure."

"And what are you thinking?" the older erythrocyte inquired.

AC hesitated. She was comfortable enough discussing this with AE 3803, yet didn't know her senpai that long. Then again, she had given her kohai good relationship advice in the past. "Honestly? I'm not sure how to put it, but I don't know if I feel…well, strongly enough. Does that make sense?"

"As if anyone can measure feelings, but I think I know what you mean. Here." AA 5100 put down the basket with nutrients she'd been carrying and covered AC's eyes with her hands.

"What?"

"No thinking," the other erythrocyte instructed. "Clear your head. Now, just picture him."

It was almost impossible to do that without imagining him grinning or at the very least smiling, regardless of whether is uniform was in pristine condition or bloody and torn up. He was just a positive person, a trait she'd come to cherish, especially whenever she'd needed someone to comfort her like after FP's death. Yeah; no matter how silly he seemed at times with his antics, brightening her days, you could count on him and when things got serious so did he. He undoubtedly cared for her and admittedly he meant the world to her too.

"You're already smiling," AA's voice suddenly told her amused, interrupting her thoughts.

"Seems like there was no reason to worry after all," the redhead chimed in merrily.

AC managed a timid smile, before turning to her friend. "AE, when did you realise that you had feelings for 1146?"

"I just did," the she confessed, smiling warmly. "I saw another couple kiss and I just thought of him, us doing the same. I thought of all the things I loved about him and knew that I wanted to be with him. Though back then I thought it was just one sided."

"Well, that shouldn't be an issue in this case," AA pointed out. "You're neutrophil friend is hardly subtle, even if he hasn't said anything yet."

"Maybe he too is nervous," AE 3803 suggested. "It's a big step."

"Well, when you two first met you were afraid of white blood cells, weren't you?" AC nodded, making the other red blood cell sigh. "I could see how that might play a part in making him hesitant to push things further."

"Yeah," AE agreed almost feverishly. "Maybe he's waiting for a sign from you…or something."

"Maybe you should be the one to tell him," AA suggested. "That way you also won't have to worry about getting caught off guard and can prepare yourself if that's what you need."

"You have a point." Frankly she had no idea how to start such a conversation, but initiating it itself did sound better than getting caught unawares by it.

"Hey, things are going to be fine," the older erythrocyte assured her, probably seeing how she was starting to think everything through. "You two are practically acting like a couple already."

AC looked at her surprised; was that really the impressions others had? Then again CT had implied much the same not long ago as well. "We are, huh?"

"A little," AE agreed.

So, everyone already thought they were a couple and 4989 did seem somewhat infatuated. He tried to be subtle, but as AA 5100 had already mentioned, he wasn't particularly good at it and so AC had picked up on how differently he treated and acted towards her compared to anyone else. Maybe it really was time to talk with him about that, about them. "Well, then I guess it's time I make a move. Right?"

AA sighed and placed her hands on both her and AE's head as she shook her own. "You two are hopeless."

"You want to say something, don't you? I know that look."

4989 glared suspiciously at his friend, who briefly chuckled. "I just still find it strange that you stall confessing to AC," 1146 explained. "When I found out how I felt about AE, I wanted to clear things up as soon as possible."

"Well, she was actively avoiding you, so it was a somewhat different situation," the fluffy haired neutrophil reminded him.

"True, but it was because she thought I didn't return her feelings and feared to ruin our relationship forever." 4989 gave his friend a meaningful look; that was exactly what he was worried about. 1146 sighed and continued. "Look, it really messed her up and I don't want you to go through the same."

"Sure I'm nervous, but it's not that bad."

"Yet," the other neutrophil added. "Tell her."

Suddenly the lactic acid bacterium on 4989's shoulder threw up its little flippers. "Nyuuu!"

The immune cell picked it up, letting it sit in his palms as he held it in front of him. "So you too think I should, huh?" he asked it.

"Nyu! Nyu!" the cute prokaryote chirped excitedly, nodding its head as it seemed. It was difficult to tell with the lack of neck.

"You're right," 4989 finally, if begrudgingly, admitted. "You both are." And he wanted to, he really did. He wanted what his friend and AE 3803 had with AC.

Suddenly 1146 placed a hand on his now free shoulder. "Then promises me this: the next time you're with her, just the two of you, you'll be straight with her. There are plenty of little parks around everywhere where you can have some privacy."

4989 took a deep breath. "Promise."

Wait; if they met the erythrocytes back at the lungs again, would 1146 purposefully lead AE away just to force him to fulfil his promise? That would mean he'd have to tell AC…today. 4989 gulped and petted the little bacterium in his hands, hoping to calm his nerves.

He could do this, right?

Well, he still had a bit of time to come up with the right words.

"Is it just me, or is the elevator slower than usual?"

AC and AE had both completed their deliveries and were back in the lungs, having taken the elevator to reach the alveoli. For some reason however it was all but crawling, as if it was struggling to move.

"Maybe we have a very slow breathing pace. According to the circadian rhythm the body is sleeping right now," AE said.

"Oh, right." With the body being always so busy it was often hard to tell. This was still strange though.

Finally the elevator reached their floor, shaking as the doors opened with a screeching sound. Having never experienced something alike AC got disconcerted and as soon as possible jumped out of the cabin into the hallway, AE right behind her. They didn't get very far though.

AC's eyes widened. "What is…?"

"Vines?"

The once spick and span hallway was overgrown with plants, vines crisscrossing from with greenery covered wall to wall and ceiling to floor. "How did these get here?" AC wondered aloud, noticing that along the vines were a lot of the same blue flowers 4989 had put into her hair.

"I don't know," AE confessed. "Should we turn around maybe?"

Both erythrocytes looked back, seeing that the elevator's doors had closed, equally covered in vegetation from the outside; no wonder they had struggled. "Elevator is already gone and we're not exactly supposed to go back that way." Not to mention that she didn't want to go back into that thing, not after the way it had shook.

"I think we could squeeze through," AE suggested with a nervy smile in a unsuccessful attempt to look confident. "It doesn't look narrower than most capillaries."

They really didn't have much choice, did they? "Okay, but we should report this as soon as we see a leucocyte. I'm sure the alveolar macrophages should know about this."

Her fellow erythrocyte nodded and boxes in hand they began to search their way through the vegetation. They were slow, needing to push aside smaller vines, while finding themselves blocked by thick curtains of greenery they needed squeeze past. Once or twice the boxes almost got stuck, but eventually they reached a door leading into a chamber for the gas exchange.

AC tore a vine off and went for the handle. "The door is a bit stuck," she said as she tried to move it.

"Can you open it?" AE asked, looking around as if she was worried the plants would attack them.

Using more strength and pushing her body against the door, AC managed to shake it loose, green dust snowing down on her. Finally the door opened. "Yeah. Meet you at the end of the corridor."

AE nodded. "I'll try to hurry up; really don't want to linger here any longer than necessary."

"Me neither," AC confirmed. "Good luck."

AE disappeared behind another plant-curtain out of view and AC entered the small chamber. For a moment she wondered if she should keep the door open just in case. She decided to leave a gap, enough for her hand to fit through and turned to the machines. They were just as covered as the walls in the hallway, making her question if they would even work.

She sighed and walked across the room, until there was a cracking noise beneath her and AC froze up. The erythrocyte looked down, staring at fissures surrounding her feet. Through some vines had already broken through into the chamber, more flowers sticking out here and there.

AC took a deep breath and swallowed hard. Very carefully she lifted a foot, only to see the cracks around the other multiplying. No, no, no, no, no. Screw this, she had to get out, find another chamber. If she had mitochondria they'd probably be drumming in her chest right about now. Just go back to the hallway.

Slowly she placed the lifted foot behind her.

AC heard the floor crack again, she felt herself lose footing, as it collapsed. She was too surprised to even scream at first, when suddenly there nothing beneath her feet and she fell.

Chapter Text

Mycosis

Part 2

AE 3803 cried out, when the floor under her collapsed. Desperately she tried to grasp the door handle, but it simply slipped through her fingers. Her back hit a particular big vine, her limbs getting caught up in several more, albeit smaller ones. They slowed her fall, yet as they did, also wrapped themselves around her. By the time she came to a stop, AE was completely wrapped up in the greenery like a fish caught in a net.

The erythrocyte hissed in pain, feeling several shallow scratches along her arms and legs, her back hurting a little from the initial impact. Why did these things keep happening to her?

AE turned her head as best she could, trying to figure out where she was. What the red blood cell saw made her haemoglobin sink into her shoes.

The alveolus was in ruins. Not just her capillary had collapsed, but the entire interior structure seemed to have crumbled, as if it been hit by a massive earthquake. Above she could see up several storeys and it was the same when AE looked down through holes all around her, while she herself was hanging above the mostly intact floor of another capillary.

And then there was the greenery. Everywhere were vines, leaves and blue, dandelion-like flowers of varying sizes, covering every surface and breaking through walls. Had they been here this morning?

AE knew she had to get out. It was only a matter of time before this place collapsed completely.

She tried to move her limbs, but the vines were so tightly wrapped around them that AE hardly managed to eve lift them. For the time being she as pretty much immobilized.

Realising she really needed help, AE looked about once more, this time hoping to find another cell. It was quiet around her, though there was a light breeze tugging at her red hair and beret. Vines and leaves were swaying gently as well, but they seemed to be the only things moving. She was alone.

"Hello!" AE shouted. "Anyone?!"

There was no answer and the erythrocyte swallowed nervously. What now? Surely the immune cells would find about this, whatever it was. Hakkekkyū-san would start to worry when she didn't show up and search for her. If so, then she just needed to be patient.

Yes; he and…

AE's eyes widened, and she scolded herself for being so forgetful. AC had to be around here somewhere, after all the entire storey had collapsed as far as she could tell. "AC! AC, can you hear me!"

Once more there was only silence. Troubled AE 3803 looked around, hoping to find anything red that could indicate her friend's whereabouts. She wasn't sure where to look, as the fall had thrown off her already questionable sense of direction, but then she saw something.

Next to her was a slope created by several pieces of debris, leading down at least another two floors, perhaps even further, but between the vines she could something red. There was no way of telling who it was, or even if it was part of an erythrocyte's uniform. If it was AC, maybe she hadn't heard her yelling due to the distance and the wind. AE hoped that her friend wasn't hurt, realising that she had easily fallen twice as far, but there wasn't anything she could do. As so often, all the erythrocyte could do was to wait for the white blood cells to save them.

4989 sighed as he squeezed his way through the crowd leaving the right ventricle, closely following 1146. He'd never liked going through the heart, not just because it was always tightly packed, but there were always the edges of boxes jabbing into his sides or abdomen. Due to that he'd made it a rule to avoid the heart with a full phagolysosome if possible.

Phagolysosome

A lysosome is an organelle found in many cells, containing hydrolytic enzymes to break down various substances, which is why they are sometimes referred to as the cell's stomach. When phagocytes, like macrophages or neutrophils, engulf and 'swallow' a pathogen or something else, a spherical vesicle called phagosom is created, which then fuses with the lysosome, creating a phagolysosome. Within it the phagocytized material is then digested.

The two neutrophils had successfully returned the lactic acid bacterium and were on their way back to the lungs. 4989 wondered if the two girls had already made it back and his mitochondria suddenly fluttered.

His friend hadn't said anything, even after some inquiry, but he was convinced that 1146 would take AE 3803 aside to give him and AC some privacy. The entire way from the intestine 4989 had pondered about what to tell her, or perhaps more accurately, how to confess to her. Truth was he had nothing, at least nothing he was satisfied with. He would probably end up stuttering, trying to wing it.

Meanwhile the road split before them, one street leading to the right, the other to the left lung. As their destination was the pulmonary vein, it really didn't matter through which they went, but then 4989 spotted a group of fellow neutrophils headed for the left one. There were even more coming from the right lung.

"Have we missed something?" 4989 asked aloud. They hadn't received orders, so it was possible that only white blood cells in the immediate proximity of the lungs had been called in.

He saw his friend's visible eye narrow. "Let's find out; maybe they could use our help."

Picking up the pace the two followed their fellow neutrophils into the left lung, only to find it bustling with immune cells, mostly monocytes, alveolar macrophages and neutrophils. There were even a few NK cells and a few lymphocytes. It looked like there was going to be a battle, a big one.

"What happened here? We weren't gone that long."

"Looks like they are sectioning off some of the alveoli," 1146 noted, pointing to some of the elevators, where a few of the alveolar macrophages in their pale blue dresses were standing guard.

"Wonder what got in this time," the fluffy haired neutrophil replied, in his head already going through the list of possible bacteria. The very low number of lymphocytes made a virus unlikely, unless of course none of the lymph nodes had been contacted yet.

Together they approach a nearby macrophage, who was apparently giving orders to a few monocytes. As soon as they were dismissed and had left, 1146 addressed her. "Alveolar Macrophage, what is going on here?"

"Oh, it appears that a few alveoli were infiltrated by a fungus," she explained, a hand resting against her cheek. "Its hyphae are blocking capillaries, and we worry that fragments might break of and spread through the bloodstream."

4989's eyes widened. "It's a mycosis?" he uttered surprised. "How is that possible?"

Mycosis

A mycosis is an infection caused by a fungus, often through inhalation of fungal spores or localized colonization of skin and dermal appendages such as nails. These fungi are often divided into dermatophytes that only infect the skin, yeasts and moulds, which can infect the skin, the mucosa or cause a systemic mycosis, meaning they can infest internal organs. Many of the fungi responsible for systemic mycosis are usually only dangerous for those with an already impaired immune system, or who already suffer from another serious ailment.

"Well, the respiratory super-infection wasn't that long ago," 1146 reminded him. "It's possible it slipped in during the battle, or when we were handling the massive clean-up. Besides, our numbers are still quite depleted."

"True," the other neutrophil said glumly. So many had died in defence of their world, and he had almost shared that fate. Still, surely a mycosis wouldn't be that bad and besides, weeding fungi was something neutrophils were trained for just like Killer T-cells excelled at exterminating viruses. "Is there any way we can help?"

Alveolar Macrophage gestured towards the gathering immune cells behind her. "We're currently waiting for reinforcements to clear the affected areas. You are welcome to join us once we begin with our sweep of the alveoli."

"We'd be happy to help," 1146 assured her and 4989 nodded in agreement.

"We'd be much obliged, neutrophils," Alveolar Macrophage replied with a warm smile. "I will see you in battle then."

She departed, joining a group of her colleagues, and the fluffy haired neutrophil sighed. "Afraid AC and AE will have to wait for us then."

1146 smiled. "Maybe this will take your mind off for a while," he suggested.

4989 twisted his mouth. "Don't act like you weren't nervous, when you were in my position."

His friend merely shrugged, but when he opened his mouth to say something, he was suddenly interrupted. "U-1146, U-4989! I'm so glad to see you."

Both neutrophils turned around and saw AE 3803's senpai running towards them, looking quite distressed. "AA 5100, is something wrong?" 1146 asked once she reached them.

AA hesitated for a second, but then nodded. "I'm afraid so. Well, I'm actually not entirely certain, but the thing is…," she took a deep breath. "I met AE and AC on their deliveries and we walked the rest of the way together. We split up here and wanted to meet at the pulmonary vein, wait for you guys to arrive."

4989's cytoplasm ran cold. "What are you saying?"

She grasped her wrist and squeezed it tightly, looking to the floor beside him. "The elevator they took; it would have brought them straight into one of the infected alveoli."

"Are…are you sure?"

Their eyes met; she looked at him guiltily, and he wondered if she felt responsible for what had happened to her kouhais. "Yes. I've waited in the vein, but they never came. I started to ask around, but no one has seen them, actually no one as seen anyone leave those alveoli in some time. That's when the immune cells started gathering around the affected areas."

"No that can't be!" 4989 exclaimed, shaking his head. It couldn't be.

1146 grasped his shoulders firmly. "Calm down."

"AC…"

But his friend looked him straight in the eyes. "We'll find them," he said, not a hint of doubt in his voice, though 4989 was sure to momentarily see a flicker of worry in his expression, despite 1146's best efforts to remain collected. "We're going in there and find both."

"Right," 4989 mumbled as his friend let go of his shoulders again. Of course 1146 was worried too and certainly just as eager to find them. The good thing was he never did fail to locate AE 3803, particularly when she was in trouble, which would also mean finding AC.

If anything happened to her...

"Please do and watch yourselves in there," AA 5100 said, looking a bit more at ease now.

"We will," 1146 assured her, before turning to 4989 again. "Come; maybe the macrophages will allow us to get in there first."

AE 3803 couldn't remember having ever been alone for so long. Being a cell among countless others usually meant that there was always someone around and a truly quiet place wasn't easy to find. The redhead didn't mind, but it made the silence within the ruins all the more disquieting, as she hung there trapped and immobile. It was just so…lifeless.

She'd shouted for help and AC a few more time, however again to no avail and so AE gave up and instead opted to listen, hoping to hear anyone really. Even Memory T-Cell would have been a welcomed sight.

For the time being however there was only the wind, along with the rustling of vines and leaves. Somewhere parts of the alveolus' construction creaked, but thankfully all remained stable as she could hear nothing break or collapse, which was a small comfort.

AE was more concerned with the possibility of germs entering this place, given the damage to the structural integrity. Could a bacterium find her before Hakkekkyū-san got to her?

Quickly the erythrocyte shook her head, dismissing the idea. No, he always came to save the day. Today would be no different.

More time passed and AE 3803 found that she could actually watch the strange vegetation slowly grow and spread before her eyes. Eventually, she lost sight to the adjacent rooms and the level below where she suspected AC to be trapped in, the dot of red not having moved until it had disappeared from view. Her arms and legs also started to burn a little, probably from being kept in such an awkward position, though that accompanying itching sensation was making it worse.

AE took a deep breath to calm herself. She would have to wait a little longer.

It sure was an invasion, but unlike any other 1146 had faced before. There wasn't really an enemy to fight, no battle, no outmanoeuvring or traps, just greenery that needed to be cut down. He and 4989 were working their way through the partially collapsed hallways of the alveolus AA 5100 had pointed them towards, their knives cutting effortless through the vines, but thanks to the sheer mass it was time-consuming work.

His friend was edgy and unusually quiet, hacking away at the fungus with harsh slashes. 1146 too felt unsettled, but knowing that him panicking would help neither Sekkekkyū nor AC he focused on the task at hand. There was a cinnamon-like smell in the air, which only got stronger the further they went in. It was as if someone had burned incense sticks, lots of them, though he was getting fuzzy-headed, making him all but certain that the plants surrounding them were responsible.

Sap dripped from the severed vines, the hyphae of the fungus, along with brown dust. When 1146 breathed some of it in, his suspicions about the scent were confirmed. The particles were too small to be the fungu's spores, the conidia, their effect making him think of mycotoxins instead. They really shouldn't linger any longer than necessary.

Mycotoxins

Toxic metabolites produced by fungi, harmful to other organisms or even capable of causing disease.

Some like the aflatoxins produced by members of the Aspergillus species are dangerous to humans, damaging cells or inhibiting their functions, while others can be used as antibiotics to combat bacterial infections, such as penicillin derived from the Penicillium mould.

Suddenly 4989 paused. "You see that?" he muttered, 1146 barely able to hear him.

"What is it?"

"These flowers…"

Then he saw them. Along some vines were indeed blossoms and to his surprised 1146 recognized them. They were the same that he'd seen in AC's hair. "4989…," he began, seeing how rigid his friend's body had become.

"I picked these and put them in her braid. I didn't realise they were from the fungus," 4989 began, voice shaking. "If I had, neither of them would be in danger right now, I could have warned the alveolar macrophages. What if I help spread this thing through the body?" It was possible; these flowers were the fungus' vesicles from which the spores grew and were released from, giving them the dandelion-like appearance.

"Then it's going to be dealt with swiftly, now that we know about it," 1146 told him. "And don't blame yourself; no one took notice of it for days. Look how far the fungus has spread. I didn't recognize them, when I saw them in AC's hair and the resident macrophages didn't realise the danger either. We all failed, it's not your fault."

They were all tired and overworked after the past few weeks, but he knew 4989 would blame himself regardless, if AC 4293 had gotten hurt…or worse. The fluffy haired neutrophil stared at the flowers for a few more moments, before he angrily hacked away at them.

Sap splashed across his uniform like a bacterium's cytoplasm, some hitting is face. "Arrgh!" 4989 hissed, quickly wiping it off. "Damn that stuff burns."

1146 examined some of the remaining flowers more closely and finally recognized what exact species they were dealing with. It actually was a common fungus, an opportunist the body was actually used to dealing with. If only the super infection hadn't depleted their numbers.

Aspergillus fumigatus

One of the most common moulds that can be found world wide. Spores are inhaled by most people on a daily basis, though they are disposed of by the immune system(primarily alveolar macrophages) in healthy people, thus they usually only pose a threat to people with an impaired immune system or a chronic disease. However, individuals recovering from severe respiratory infections like influenza are also at a higher risk or those with an allergy to the fungus.

A. fumigatus mostly infects the lung (pulmonary aspergillosis), but can spread into other regions (invasive aspergillosis). At least one of its toxins (gliotoxin) possesses immunosuppressive properties, including but not limited to the inhibition of macrophage phagocytosis or the induction of apoptosis in various cells, among others in phagocytes such as neutrophils.

1146 touched some of the sap with his gloved fingers. "Must be its haemolysin." As if the other mycotoxins weren't enough; he could still feel himself becoming more and more dazed the longer they were breathing in the stuff.

His friend's eyes widened in horror, suddenly looking wide awake. "The erythrocytes!" he exclaimed. "We have to hurry!"

Despite what had just happened 4989 started to redouble his efforts to cut a way through the fungus' hyphae, sap splashing, bits and pieces of leaves and flowers alike flying to all sides. 1146 however noticed that his friend's movements were lacking precision and given how he himself felt, he was certain that 4989 too was suffering from the effects of the mycotoxins.

It didn't take long until he heard his friend snarl in pain and 1146 was shocked to see cytoplasm drip to the floor. "Slow down," he cautioned 4989, shaking his head in hopes of ridding himself of the dizziness. "The mycotoxins…you'll only hurt yourself."

The other neutrophil turned to him, his knife bloody and a large cut across his free hand, which he had probably used to tear away a few more vines. He could plainly see the desperation in his eyes, his fear. "And the longer we stay, the more these toxins will mess with us. She's...they are in here somewhere. We can't stop."

"I wasn't suggesting that," 1146 said, stumbling towards him; his legs didn't quite seem to listen to him anymore. "But we won't be able to help them at all, if we accidentally kill ourselves."

Apoptosis

The programmed cell death or suicide of a cell, among others to eliminate antiquated or degenerated cells or for number control and tissue size. This can be caused by both internal as well as external signals, even certain toxins created by pathogens.

4989 looked like he was about to reply, but then closed his mouth, biting down on his lower lip. Whether he was shaking because of fear, frustration or the toxins 1146 couldn't tell. Eventually, he just turned around and proceeded to clear a path, slower now, if only a little.

1146 joined him, having to focus on every move he made. Of course he too feared for them, especially AE. He wouldn't forgive himself either if he let her down now.

Together they continued on in silence, occasionally hissing or snarling whenever they managed to hurt themselves or the vines proved especially resilient. Thankfully their injuries weren't too deep, at least for now. 1146's head still felt as if it was filled with fog. Was this what erythrocytes experienced, when they were exposed to alcohol?

The hallway continued on, with parts of the upper floor having already collapsed, blocking part of the way. One after the other they squeezed past what probably had once been a sturdy wall. 4989's knife brushed against it, creating a loud scratching noise that made 1146 flinch.

"Hello? Is someone there?"

1146 and 4989 looked at each other, the former suddenly feeling a lot more awake again. The voice had come from somewhere close by, clearly female, though it had been somewhat muffled.

"The door," 4989 panted, swaying a little as he walked, pointing towards the entry to a capillary, the door having been replaced by greenery. Invigorated by finally having found someone, the two neutrophils removed the hyphae as quickly as possible in their state.

As soon as the last vine was cut, they were greeted by a fresh breeze of air. It was like being doused with cool water, 1146's mind suddenly a lot clearer. Eagerly he took a deep breath, his mitochondria probably rejoicing. Looking around he found himself in what had once been a capillary for gas-exchange given the overgrown machines in a still standing corner. No wonder there was such a fresh breeze; outside-air had to be leaking through this close to the alveolus' surface and with the hyphae going through every wall.

Only a few steps away was an erythrocyte, wrapped up in several vines like in a net, evidently having fallen through the collapsed ceiling. Then he saw red hair.

"Sekkekkyū!" 1146 stormed over to the red blood cell and pushed the vines apart.

AE 3803 stared at him for a moment, only to tear up a second later, a smile spreading across her lips. "Hakkekkyū! 4989! You're here!"

Relieved he reached out for her, gently cupping her bruised cheek. "Are you alright?" It was as if a great weight had been lifted from his chest.

She nodded. "I'm fine, I'm fine, just a bit wrapped up. What is this thing?" Only then did she apparently see the cuts across his arms, the cytoplasm staining his uniform. "What happened to you?"

1146 just shook his head. "Scratches, never mind them. This is a fungus, a…"

"Where's AC?" 4989 jumped in, showing up next to 1146, understandably still agitated.

His appearance startled her momentarily, but then AE looked to her right where part of the floor was missing, though the view into the lower levels was mostly blocked by vegetation. "She went into another capillary just a minute before everything collapsed. I'm not sure, but I think I saw her down there. I lost sight when the greenery became too dense."

"Go," 1146 told his friend.

Without hesitation 4989 nodded and jumped down through the hole in the floor. They could hear him land and slide across what was probably a slanted piece of debris, disappearing deeper into the ruins.

"You think she's alright?" AE asked worriedly, looking after the other neutrophil.

"Hopefully she's trapped just like you and I'm sure 4989 will not rest until he had found her," 1146 assured her as he started to cut down the vines holding her. "The good thing is the fungus is only filtering the bloodstream for nutrients, not actively hunting erythrocytes."

"That's a relief."

He nodded. "Still, we should hurry. The others have probably already started to weed out the fungus' mycelium, that's what we call the entirety of these vine-like hyphae, which given how far the infiltration has come will only undermine the structural integrity further."

"Are you saying this entire alveolus could collapse?!" AE exclaimed alarmed.

"Possibly," the neutrophil admitted. "I'm going to get you out and then see if I can help 4989. Have you seen any other red blood cells around?"

She shook her head. "No, only the two of us."

"Good. The affected alveoli have already been blocked off. If we're lucky there aren't too many still trapped." There would of course be casualties, there always were, cells of the alveoli itself most notably, but the body as a whole would likely not notice anything.

"Sorry I got myself into another mess again," AE mumbled, her cheeks flushing red, looking away in shame.

1146 however gave her a comforting smile, lifting her chin up, so she would see it. "Don't worry about it. Let's focus on getting you out of it." No matter how many times she got into danger, he would gladly get her out. Duty or not, he loved her after all.

The vines were tight around her ankles, preventing her from moving her legs, while many more had wrapped themselves around the rest of her body. They kept her suspended well above the ground and pretty much upside down, her beret long lost, with only one of her arms having remained free.

AC had tried in vain to free herself, not having the strength to either tear the vines apart or even loosen them. She had no idea how long she'd been hanging within the ruined remains of the alveolus, all tangled up and bruised from her fall. She actually had been knocked out by her abrupt stop, awakening only when the wind had picked up. It hadn't stopped since, her 'cocoon' constantly swaying in a steady rhythm, the gusts coming in through a crack in the pneumocyte-wall created by the plant, exposing her to the outside air. Despite having been warmed up in the upper respiratory tract it was still cool to her, given that she was used to the body's core temperature, and AC was shivering, envying her male colleagues' long trousers.

To make her situation worse one of the vines had been snapped by her fall and sticky, burning sap was occasionally dropping onto her uniform, having already eaten a hole through her jacket. It wouldn't need much longer to get through the t-shirt as well, and she could already feel her membrane tingle uncomfortably.

AC tried to move a little again, just enough to get out of the way for the drops, when she suddenly heard something. It sounded almost like steps and someone sliding across the debris. There also was that familiar sound of something being slashed. Could it be a white blood cell? Finally!

With her hope sparked anew she was about to shout, when another thought occurred to her. What if it was a germ? With the alveolus damaged as it was, who knew how many bacteria could have entered and many of them had claws that could slash as well as any knife. AC had no desire to attract their attention.

She decided to remain quiet, refraining to listen instead. Having spent so much time around neutrophils she had a pretty good idea what sounds their equipment made when they moved and hoped that some distinct sound would tell her who or what actually made those noises.

Looking over to a wall of vines she stared at a few familiar blue flowers, the very same 4989 had put into her hair. It was obvious now that they belonged to whatever had invaded this lung, but evidently he hadn't recognized it. Well, apparently no one had recognized it, though it would surprise her if the immune cells weren't doing anything about it now.

The wall of vines began to shiver and not because of the wind, until it was swiftly cut apart with two clean strikes. AC held her breath, hoping it wasn't a germ.

It wasn't, instead she looked at a stained, white uniform, a little torn but undeniably belonging to a neutrophil, who stumbled through the opening he'd created. Finally, he lifted his head and spotted her as well.

"AC!"

"Hachikyu-kun!" Her haemoglobin jumped in her chest when she saw him running towards her, looking perhaps even more relieved than she felt, if that was possible. He was here, he'd made it!

"AC!" He grasped her free hand, the only thing he could reach due to her still being suspended and she noticed that he seemed to be close to tears as well. "I found you. Thank goodness I found you. Are you hurt?"

She shook her head, smiling at him, fighting to keep herself from crying, her fingers eagerly intertwining with his. "A bit bruised, but otherwise I'm fine. I got tangled up in the vines, and they thankfully slowed my fall." Knocked out was after all still better than getting squashed by impact.

He actually looked worse with his ripped uniform and a few nasty looking cuts along his arms. Strange; she hadn't seen any thorns or other sharp edges. Had he encountered germs on his way here?

"I'll get you out," he promised confidently, despite his still shimmering eyes . "These are the hyphae of a fungus that has infected this lung," 4989 explained as he began to climb up another vine in order to reach those trapping her. "Can't believe we let them spread this much."

"Is it dangerous?" She was surrounded by the devastation it had caused here, but could it threaten the body as a whole?

4989 started to cut, careful not to accidently hit her and as she noticed mindful not to let the sap near her either. "Well, most fungi only cause problems if the immune system is compromised."

AC's eyes widened. "The super infection." Those weeks of nonstop fighting had left the immunes system understaffed and the body exhausted. It sometimes felt that most neutrophils she saw nowadays were band cells just out of the bone marrow.

"That's our best guess," he confirmed before she saw him furrow his brow. "Should have recognized the flowers," 4989 growled, clearly scolding himself.

"You've ever seen this fungus?"

His movements slowed for a second. "No, not in this state anyway," he admitted. "I've see a few spores, which the alveolar macrophages usually took care of before they could take root, never the mycelium with fully blooming vesicles. But new flowers don't pop up for no reason. Stupid."

"Hey, even the macrophages missed them," she reminded him; only more evidence of how depleted the immune system still was. In any case AC wasn't going to blame him. He was here; that was all that mattered to her.

"Well, they've noticed now."

As if someone or something had heard him, the room suddenly shook and a few vines along the pneumocytes snapped, causing parts of the wall to break off. A fresh gust of cool wind washed over them, stronger than any other before.

"What was that?" AC asked alarmed, now able to look outside into near complete darkness. It was more than just a little unsettling and she shivered for a different reason than the cold. She wanted nothing more than to take his hand again.

"They're cutting down the fungus, before it can keep spreading," explained 4989, now quickening his pace. Her other arm was already able to move again, and she could feel the vines around her legs loosen up. Just to be safe AC held on to a few vines, so she wouldn't immediately fall once she was free. "Right now just a handful of alveoli are affected, so we can still keep it contained."

"I'm guessing they don't know we're still here?"

"Or that the pathogen is the only thing holding this particular area together. Don't worry; I'll have you out in a second," he promised, reaching for the last bundle. "Almost."

Just when his knife touched the vines, the area shook anew, much more violently than before. This time the room they were in couldn't take it. The outer wall broke away completely, the floor disappeared into the abyss as many of the vines that had infiltrated them turned brown and snapped. They had simply died off, probably having been cut off at some other part far away by some leucocytes. Including those still holding AC.

For the second time she fell, wind howling around her like some angry beast, sweeping away the last of the flowers in her hair.

This time there was nothing but darkness beneath her.

"AHHH!"

A hand grabbed her by the wrist, grip firm as a vice. "I've got you!"

Chapter Text

Mycosis-Part 3

"I've got you!" 4989 repeat loudly over the howling wind.

Shaking, near frozen in fear, AC looked up, seeing him holding on to a still green vine with his other hand. Quickly she clutched the one holding her by the wrist, hoping the already damaged sleeve wouldn't tear. AC 's voice trembled as much as her body, when she managed to speak again. "I think I preferred the wave in the intestine," she tried to joke in an attempt to calm her own nerves.

"Tell me about it," 4989 said, mustering a small smile somehow, before AC turned her head to look at the abyss. There really was nothing, just the outlines of the terminal bronchiole and other alveoli, but the wind would probably simply suck them out. Oh, she shouldn't have looked. "Hey, look at me!" the neutrophil all but snapped at her and startled she lifted her head. "I'm gonna have to climb, so if…oh, no."

"What?" Only now did AC realise that the vine was actually attached to the far away ceiling on both sides, meaning 4989 had managed to grasp the slacking middle part. Problem was it was starting to rip at both ends, unable to support their combined weight.

If she'd had a heart, it probably would have stopped in that moment. Instead time seemed to slow down as her mind raced. The vine would tear, and they both would fall into the bronchiole. They were both going to die. The realisation hit her like a block of ice. If only she hadn't gone into the capillary, if only she hadn't taken that stupid risk.

Then suddenly she felt very, almost unnaturally calm. No. He didn't have to die.

The vine wasn't able to support them both but maybe it could support one.

And she let go.

4989 turned to her, saw that she had relinquished her hold on him and his eyes widened in horror. "AC?"

"Let me go." She had no idea how her voice sounded so composed.

"What?" he breathed shocked, clearly not believing what he'd just heard.

AC smiled sadly at him, but she had made her decision. "The vine will snap any moment. You have to let me go."

Instead his grip tightened, probably bruising her, but that didn't matter anymore. "No!" he exclaimed, sounding heartbreakingly desperate. "No, I won't!"

"Hachikyu," she softly insisted, feeling the first tears in her eyes. "We don't have time to discuss it, and you'll never make it up there in time with me weighing you down." She couldn't let him die, not because of her and not when she could do something about it. She would die either way. If her last action in life ensured that he survived she would be at peace.

But 4989 shook his head. "We'll see about that!" he snarled defiantly, clearly fighting tears himself. "Now hold on!"

"Hachikyu…"

"No!" To her surprise he actually managed to pull her up, until they were almost face to face. "Wrap your arms around my neck; I'm gonna need both my hands!" AC hesitated. "Please," 4989 begged, his voice all of the sudden a lot quieter and finally AC complied, not having the heart to refuse his request; it very nearly broke just seeing him so desperate and full of fear. "Don't let go, don't you dare let go," he told her, whispering with his now shaky voice.

AC merely nodded and he let go of her wrist to grasp the vine with both hands. Now it was up to her; if the vine were to rip any further, she could simply remove her arms from around his neck, push herself away and he'd be saved. He would perhaps never forgive her, but he would live. One move would ensure that.

The erythrocytes swallowed hard. Perhaps it was for the best that she'd never gotten to tell him. Perhaps it was better that certain things between them hadn't been addressed after all; it would make it easier for him. Still, a part of her deeply regretted that they had never gotten to, that she'd taken so long to sort her feelings out, but it was too late now. This was goodbye.

To her surprise however he didn't start climbing, instead he reached for one of his knives. AC watched puzzled as he reached for one of the vines. "Hachikyu?"

"Hang on!"

"What?!"

And his knife cut through with one swift move. AC gasped as they suddenly swung downwards, 4989 now holding on again to their half of the vine with both hands. Looking over her shoulder, she could see that they were headed straight for a lower level of the alveolus they had fallen out of. Then 4989 let go of the vine, sending them both flying.

Instinctively, her previous plan forgotten, AC hugged him tighter. What was he doing?! They were plunging towards a large window, and she braced herself for the impact. Then several things happened in quick succession.

4989 threw the knife he'd somehow managed to keep in his hand and tossed it at the window, the blade piercing the glass and getting stuck all the way to the hilt, causing the entire surface to crack. Without hesitation he then embraced her, wrapping his limbs around her, pressing her head against his chest and his own head on top of hers, until she was all but enclosed.

AC couldn't see anything, only heard glass break, his body shuddering as he went through it back first and she closed her eyes. The shattered window rained down around them just as they too hit the floor. His body cushioned her impact, but she flinched nonetheless, as she tried to make herself as small as possible.

At first AC remained frozen, she didn't even breathe though they'd come to a stop. She could still feel the weight of 4989's arms around her, but there was no pressure anymore, they felt…limp. Finally, she opened her eyes again.

All she saw at first were his white clothes as her head was still on his chest, her hands clutching at the fabric. Carefully AC lifted herself up and his arms simply slid off, landing on the ground with a quiet thump.

Alarmed she quickly got off 4989 and saw that he was covered with lacerations. Those on his lower arms were older and already healing, but there were now several more from the glass all over his body. There countless more shards surrounding hem, but hardly any had so much as touched her. He'd shielded her from the impacts, their crash through the window as well as their touchdown.

Worryingly his eyes were closed, while his head was tilted sideways and his cap had fallen off, now lying close by on the floor. 4989's usually fluffy white hair was a mess with quite a bit of glass in it, glinting or tinted red with cytoplasm.

Frightened AC reached out to pat his cheek. "Hachikyu-kun?" He didn't respond, and her chest tightened as her haemoglobin twisting painfully. "Hachikyu, wake up. Please."

Desperate she continued to gently slap him in an effort not to hurt him. He couldn't die, not now, not because of her. AC's eyes were welling up with new tears. No, no, no.

"Come one," she pleaded. "Wake up." She had meant to prevent this. If it hadn't been for her...

And then, after what felt like an eternity, 4989 groaned softly, his features twitching. AC breathed a sigh of relief, brushing her tears away in a hurry as she composed herself. He shouldn't have to see her all red-eyed and fearful.

4989 moved his head, sluggishly opening his eyes and looked around. It took him a moment to really wake up, but then he realised she was right there. "Are you alright?" 4989 mumbled.

AC stared blankly at him. "What?"

"Did you get hurt?" he asked again, this time more insistently.

"Did I…?" Her eyes narrowed, suddenly she was feeling furious, her fear forgotten. "I should be asking you! You're bleeding! You were unconscious!" AC nearly shouted, wondering just how many more injuries he'd received thanks to his stunt that she couldn't see.

Nonetheless, 4989 smiled, though through gritted teeth, very obviously trying to hide the fact that he was in some pain. "Occupational hazard."

"You could have died," AC claimed distressed; she hated to see him hurt, especially because of her. "The vine was about to snap and if the window hadn't shattered…"

Slowly he sat up, glass trickling to the floor and he brushed more away, when he went with a hand through his messy hair. "Hey, I promised to always try and save you, remember."

"I didn't mean…," she started, before biting down on her lower lip; she never should have asked him that stupid question all those weeks ago. "Not at the cost of your life."

"That's kind of part of my job anyway," he reminded her.

AC shook her head. "If it means saving the body, but not a single cell."

For a moment he just gaped at her. "You honestly think I would have let you go?" he quietly asked, sounding both hurt and incredulous.

"Do you think I want to be responsible for your death?" she retorted, grasping his collar, not so much angry with him, but with herself for putting him in such a dangerous situation, all too aware that it would likely happen again. FP had already died because of her taking an unnecessary and stupid risk; she couldn't lose anyone else because of her foolishness, least of all him.

But her words had hit a nerve. "So I should just stand by and let you die? Without trying everything?" he exclaimed heatedly and shook his head. "I'd never forgive myself. I'd never forgive myself if I let anything happen to you!"

"Neither would I, if you died in my stead!"

Clearly upset, he pointed at his chest, now actually glaring at her. "I risk my life every day for this body! If I can do that for complete strangers than that's the least I should do for someone I love!"

And her ire evaporated into thin air. "…love?"

Deep down AC knew that they both had probably danced around that word for a while now, trying to uphold the status quo, hesitant to take the next step. And now it had been said. Now it was out.

His grey eyes widened, his anger vanishing same as hers had, when he realised what he'd just said. "I mean, I…," he stammered, and quickly buried his face in his hands, slightly muffling his next words. "Ugh, I messed up."

AC let go of his collar and when she spoke her voice was soft. "Hachikyu?"

At first he merely spread his fingers apart to shyly peek at her, before he lowered his hands again and she saw that his cheeks had turned a pale pink.

For a while they looked at each other silently, and AC was sure that her face was just as flushed as his. In fact her entire body suddenly felt warm and tense. So much for being the one to tell him; he'd beaten her to it after all.

For a moment AC wondered what to tell, but she had trouble finding the right words. She wasn't deluding herself about her own feeling any longer, which unfortunately didn't mean she knew what to say, but perhaps words were not going to fix this. Summoning up all her courage she instead leaned closer, cupping his face with her hands and pressed her lips against his.

AC's eyes were closed, so she couldn't see his reaction, but she could feel him wince, hearing him hum in surprise, probably not having expected her to be so bold. However, it only lasted a second or two, before he cradled her head, fingers soon entangled in her hair, the other arm around her waist to pull her close against his chest. And he kissed her back.

For some reason she had expected it to be slow and careful, but she smiled when he proved downright enthusiastic. He was kissing her deeply, sending a pleasant shiver down her spine and AC sighed softly against his lips as she allowed her body to utterly relax in his warm embrace.

She wished they could remain like this forever, but eventually they both needed some air. Still, their heads remained close, noses all but touching, and AC could feel his breath brush across her lips.

4989 was looking at her with his big eyes, a shy smile on his face as far as she could tell. "I...I love you," he mumbled his face even more flushed than before.

Hers cheeks still burning as well, the kiss, these simply three words making her haemoglobin sing. "Love you too," she whispered.

Then he leaned his forehead against hers, still keeping his voice low. "So, um, please don't ask me to abandon you. I could never..."

No, he never would have let her go; asking him to do so had been cruel. She hadn't cared about him not forgiving her, yet had failed to realise that he would have blamed himself just as much, if not more. She hadn't even considered just how hard her death would have hit him, even with their feelings unaddressed. She was an idiot.

AC swallowed hard. "Never again. I'm so sorry," she apologised and pecked his lips softly.

Evidently encouraged by this, 4989 closed the gap fully for another proper kiss, his teeth playfully grazing her bottom lip. "Apology accepted," 4989 told her as he pulled away, looking much more at ease now, though there was still colour in his face. "Can't believe I've waited this long."

"How long is 'long'?" she asked curiously.

Clearly a little embarrassed he looked away, awkwardly scratching his cheek. "Probably since we went to the bone marrow that one time, you know, when we talked and played ball with the erythrocytes."

AC's widened. "That was weeks ago."

"I wanted to do it right," 4989 explained sheepishly. "1146 told AE 3803 at the retina in front of that gorgeous panorama and I wanted to make this just as special. I…I had considered doing it when we were watching the REM-sleep fireworks, but then the call came…"

"That's why you looked so dejected." She remembered that day well and how sad she'd been to see him leave during the fireworks. It had only been the beginning of one of the most trying times in her life.

Meanwhile, the neutrophil nodded. "Yeah. Afterwards, I mean after my recovery, I was looking for a new location, something just as grand. But as more time passed I started to, well, wonder what could happen if I screwed things up, or if you were even interested. So I kinda didn't want you to know until I was sure, or at least until I had found the right place and words."

"Hachikyu," AC said softly. "I already knew."

His jaw literally dropped. "Huh?"

She chuckled and sighed softly, her finger playing with a strand of his fluffy hair. "You are a lot of things, but not subtle."

His eyes turned wide. "So you already knew that I…?"

"I had a pretty good idea."

For a moment he continued to gape at her. "Then why didn't you, I don't know, say something?" he asked confused.

"Honestly? I wasn't sure about myself and if I was ready," AC confessed. "It's a big step." Well, it had been a big step.

He gave her those big puppy eyes she'd come to adore so much. "And now?"

AC laughed a little. "Now I think that I was horribly overthinking everything. I'm sorry I made you doubt," she apologized and at the same time was grateful beyond words that things had finally gotten cleared up between them.

4989 smiled and leaned closer. "Apology accepted," he assured her and pecked her lips.

"If nothing else, this still is a very memorable location," she assured him.

"I guess it is, if not as romantic as I intended," he noted, looking around.

Gently she framed his face with one of her hands, turning his gaze back to her. "I'd consider saving my life pretty chivalrous," AC said, giving him a loving smile. "And despite what we just went through, I like how events turned out."

"Me too," the neutrophil agreed, nudging her nose with his own. "You know, 2626 suggested the waterfalls in the kidney, but given how loud it is there I figured you wouldn't be able to hear anything."

"I don't know; you could have made cute little signs and who knows, with a few real flowers and those puppy-eyes of yours…"

Laughing 4989, pulled his head back and facepalmed. "Damn, why didn't I think of that?"

"There is no reason we can't still do something like that," she reminded him.

"But now you already know."

AC, however, merely shrugged. "I promise to act appropriately surprised, give Dendritic Cell a good show when he makes that photo." That particular immune cell seemed to see everywhere and be everywhere at one. Then again, maybe all dendritic cells of the body constantly shared pictures. Frankly she wouldn't be surprised if one of them had taken one within the last few minutes.

"I don't know," 4989 began, still considering her suggestion, until she kissed his cheek, seeing them turn pink once more in an instant. "I think I can pull it off. It's a bit cheesy though"

Smiling AC wrapped her arms around his neck. "Sounds just like you," she told him, her words earning her a big grin.

"Yep."

Vines died and withered everywhere in the alveolus, falling from the walls and ceiling like leaves in autumn. Soon they covered the ground, waiting to be collected by the macrophages. 1146 could hear his fellow immune cells cutting away at the pathogen everywhere, as he was on his way out, AE securely in his arm.

"It looks a bit like a rash," his girlfriend noted, looking at the red marks on her arm, left behind by one of the vines.

He'd examined her earlier, right after cutting her out of her cocoon, to his relief finding no serious injuries. "Aspergillus fumigatus produces among others a toxin with haemolytic properties," he explained to her, assume that the vines had been covered with a thin film of toxins or that they had secreted a little on contact. Whichever it was, 1146 was glad that the harm caused by them was minimal.

"Good thing I wasn't trapped in it for long," AE noted and shivered. "Do I want to know what else it can make?"

The neutrophil hesitated, but he had promised to be honest with her. "Several more mycotoxins, most design to suppress or outright kill us immune cell, but luckily it isn't quite as effective in production and application as other germs. If our numbers weren't so depleted, it never would have gotten this far."

Her amber eyes widened. "And you were exposed those toxins the entire time! You have to be exhausted; you don't need to carry me!"

"I'm fine." He assured her, his head feeling quite clear again, his self-inflicted wounds hardly hurting anymore. "Are you complaining?"

AE 3803 immediately blushed. "No," she confessed and wrapped her arms around his neck, making him smile.

1146 continued on, searching his way through the ruins of the alveolus. Elevators weren't operational anymore, and staircases were few and far between, not to mention that they too had suffered significant structural damage. Still, slowly but surely the two managed to reach the ground floor.

As he walked through the main corridor, 1146 suddenly felt a strong breeze to his right, coming from another hallway. Had the fungus broken through here as well? Deciding to check it out he took a turn, the sign above informing him that he was headed for the elevators 31 to 60.

"Hakkekkyū?" AE asked puzzle.

"Just a brief look. I'll get you out before dealing with the Aspergillus, should I find any here."

There were large windows to his right, though it was almost completely dark outside, with only other alveoli shimmering in the distance. The hallway took a slight turn, and 1146 stopped dead in his tracks.

Up ahead, just in front of the elevators and surrounded by countless shards of glass were 4989 and AC. They had their arms around each other, sitting there side by side and despite being quite banged up they looked happy. As a matter of fact their foreheads were resting against each other, lips almost touching. 1146 had no doubt that they already had.

"I guess he finally told her," the neutrophil noted, mindful to keep his voice down, relieved the two of them were alright and had finally gotten together.

"And to think just earlier today she claimed that she wasn't sure about her feelings," AE told him, clearly amused.

1146 chuckled. "I guess that got sorted out." He could relate all too well, given his own initial confusion following the first kiss AE had ever given him.

Meanwhile, his girlfriend sighed. "Yeah, but does it always have to take near-death experiences?" She had a point. The parasite plasmodium falciparum had been something of a catalyst; only after its attack and her brush with death had he'd begun to realize how much she truly meant to him, more than just a dear friend, though it had taken him quite a while. And AE's kiss had been just after a particularly dangerous fight, one in which he could have easily died had they not received reinforcements in time.

"Well, falling in love is something most cells never experience. Perhaps we require that extra push to make sense of it when we do. To realise how important that someone truly is to us," he theorized smiling at AE as he did. Her cheeks warmed visibly and she pecked his cheek.

"How about we leave them alone for now?" AE suggested. "I'd hate for us to ruin the moment."

1146 nodded in agreement and turned around again. Those two would be just fine.

"So let me see if I got this right: everyone, except us, already knew we were in love with each other."

"Yeah, probably," AC confirmed. She'd told 4989 about her fellow red blood cells giving her advice, having urged her to confess to him. Funnily enough, 1146 had apparently given him a very similar talk earlier. It was kinda amusing to think that they likely would have confessed to each other today regardless of the near-death experience.

"Dammit," 4989 laughed. "We are just as bad as 1146 and AE."

"Let's say almost."

The fluffy haired neutrophil chuckled and nodded. "Almost." But as he rubbed the back of his head, the he suddenly flinched.

Worriedly AC's eyes glanced at some of the glass shards on the ground, particularly the ones covered with cytoplasm. "How bad is it?"

He looked at his red fingertips, yet he didn't look too concerned. "Not sure, a few cuts I'd say. Feel rather superficial," 4989 said, giving her a comforting smile. "I'm guessing the cap is ruined though."

Despite trusting his judgment, she wasn't entirely at ease, after all he was still wounded. "We should have someone take a look at that. Besides, maybe we shouldn't be sitting around here all day."

"I'm pretty comfortable," 4989 chirped, gently nuzzling her cheek with his nose.

AC chuckled. "Same, but aren't we in a still liable to collapse alveolus?" As if to underline her words there was another gust of cold wind running over their heads and through their hair.

He froze as if he'd suddenly remembered where exactly they were, his mouth opening in slow-motion. "...let's go!"

The day had started out nice and peaceful, deliveries had been finished without incident, but when CT 2980 returned to the lungs she was startled by the presence of countless immune cells. At first glance macrophages and neutrophils seemed to nearly outnumber the erythrocytes, which was never a good sign, but after another second or so CT noticed that pretty much everyone was surprisingly calm.

"What happened here?" AD 5022, who had been with her for most of the day, wondered aloud.

"Probably some invading germs," CT said, which was the only explanation she could come up with at the moment. Why else would leucocytes gather? "Still, looks like they've dealt with it already, whatever it was." What confused however was the fact that there was hardly any cytoplasm on the various uniforms. Most were torn and scratched, but they lacked the typical splatters of blood. Not to mention that instead of pots the alveolar macrophages seemed to be carrying large bags stuffed with some sort of greenery, a few leafs sticking out. It looked more like the white blood cells had been gardening rather than fighting. It was all rather strange.

Her friend, however, didn't seem curious and instead was evidently just happy that they hadn't gotten involved in anything. "Excellent timing then."

"Looks like some alveoli are still off-limits though," she noted, nodding towards one of the nearby elevators guarded by macrophages. "Let's see if we can find another one."

As they walked across the hall, the two saw several erythrocytes sitting by the side, wrapped in blankets, some drinking tea. CT assumed that they had been in the invaded areas, especially once she saw that quite a few showed torn up clothes and that their membranes showed red areas, not cuts or bruises, looking kind of rash-like instead. What had gotten in this time?

Just as she wondered what pathogen could have harmed her fellow red blood cell, AD nudged her with his elbow. "Hey, isn't that AC?"

AC?! Worried CT looked around and soon spotted her auburn haired friend apart from the crowd. And she wasn't alone.

She was sitting aside from pretty much everyone else, not on the ground or a bench, but instead on the lap of the neutrophil she was so often with. AC looked tired but content, a little patch on her cheek, her uncovered hair a mess. The neutrophil meanwhile had his arms, along with their shared blanket, wrapped around her, as she was cradling a steaming cup of tea in her own hands. He looked somewhat worse for wear, given what CT could see of his uniform, mostly the legs, was horrible torn and he had a large bandage covering parts of his head. Said head was resting comfortable on AC's shoulder, until he slowly lifted it to...to kiss her just behind the ear.

CT's eyes widened at the sight, while her friend not only seemed to tolerate the gesture, but evidently enjoyed it judging by her bright smile. Clearly they weren't just friends anymore and the black haired erythrocyte watched as the two spoke briefly before AC pecked his lips in turn.

AD, who had been similarly taken aback by what had transpired, suddenly took a step towards them. Quickly CT jumped in front of him. "No, don't."

He looked at her almost reproachfully. "What?"

"That's none of our business," CT insisted, giving him a pleading look. She didn't want him to cause a scene or start some silly argument that would undoubtedly do nothing with the exception of causing misery for all parties involved. If he hadn't been able to change AC's mind before, he most definitely wouldn't now. "Come; we still have some carbon dioxide to exchange."

AD 5022 hesitated, glowered at the couple one more time, but ultimately turned away without arguing, much to CT's relief. Even if she couldn't understand AC's decision or attraction to an immune cell, it was more than obvious just how happy she was or how much she cared for him. What kind of friend would she be if she messed with that? Still, it made her a little sad how distant she and AC had become.

As she was about to follow AD, CT looked over her shoulder once more, just in time to see the odd couple being joined by three more neutrophils and two other female erythrocytes, a redhead with a few patches of her own and another with long, light brown hair, who seemed completely unharmed.

One of the neutrophils, his eyes covered completely by bangs, handed AC a beret, probably her own, which had likely gotten lost in whatever situation she'd been tangled up in. The small group gathered around the couple and though she couldn't understand what was being said picked up on how cheerful they sounded, heard laughter and saw the smiles on everyone's face.

No, there really was no need to intervene and CT turned around to follow AD.

AC would be just fine.

Chapter Text

Epilogue

He was late.

Of course 4989 being late wasn't anything unusual, given his duties; he couldn't leave an active battle, unlike AC, who could simply pick up her pace if need be. Still, she always worried a little.

The erythrocyte was waiting at their usual meeting spot in the pulmonary vein, though without an oxygen box or a basket of nutrients. She was on break, but had an appointment to keep along with her neutrophil boyfriend.

AC watched her fellow red blood cells walk by, until finally she spotted a familiar face in the crowd. Smiling, she waved at 4989, whose clothes looked pretty wet, his hair a bit of a mess, as if he'd showered in a hurry. He probably had.

As soon as he reached her, the neutrophil pulled her into the shadow of a tree, just out of crowd's view. There he wrapped his arms around her, inclining his head for a kiss... only to find her hand pressed against his lips. "Just a moment," AC interrupted. "No bacteria or other invaders in the past few hours? Teeth brushed?"

"Well…"

"Because last time I learned what Streptococcus tastes like and I'm not keen on repeating that experience."

4989 blushed pink, clearly abashed. "Sorry," he mumbled sheepishly against her fingers.

"Hachikyu…," AC scolded him softly, an amused smile on her lips as she pulled her hand away.

"I know, I know." But then he smirked. "Have another idea though."

"Oh, yeah?"

"Yep," he chirped and leaned in, only to start pecking her cheeks, cupping her face with one hand, the other arm wrapped loosely around her waist. AC started to giggle, feeling warm and light as a feather as he continued, including her forehead and nose.

"Alright," she laughed, wrapping her arms around him neck to pull him closer, forcing him to lift his head. "But just on the lips."

4989 was all too happy to comply, and AC felt that by now familiar, pleasant shiver run down her back. "So; you're ready?" he asked, while their faces were still close together, noses touching.

"Yeah, let's go."

...

With his receptor remaining silent, the two blood cells managed to reach their destination just in time for their appointment. They could hear the children laughing and shouting long before they saw the vast schoolhouse deep within the bone. Most ignored the two mature cells, as there were many erythrocytes around, delivering to the bone marrow or picking up carbon dioxide. The two headed inside, stopping by 1110's office, who had been expecting them a bit earlier, before joining a few macrophages and their class.

It wasn't the first time for these particular erythroblasts.

"Big brother! Big sister!" quite a few of them shouted. AC spotted the girl 4989 had patched up and carried on his shoulders all those weeks ago, waving excitedly from the back row.

"Hi everyone!" the mature erythrocyte greeted them in turn, taking her place beside the immune cells.

4989 was smiling brightly. "Ready for today's lesson?" he asked, receiving a of couple cheers, though even those who remained silent looked at least curious. "Now; you've all practised running away from germs, but today we're gonna expand on that. Just getting away isn't always enough, some bacteria will hunt you, so it's important you know where to run to. Anyone want to guess?"

A boy in the back lifted his hand; AC remembered him from the ball game as well. "White blood cells?"

"Yes, exactly." 4989 crouched down to be on eye-level with the children. "Remember we're here to protect you and the entire body, so keep an eye out for anyone in a white uniform. There are so many of us that there should always be a neutrophil just around a corner. But of course you can always turn to a monocyte or lymphocyte as well; all us immune cells can communicate with each other in some fashion. And we're all tasked with protecting you."

AC noticed that a few erythroblasts still looked uneasy, one or two looking away; the idea of running towards a murderous looking cell brandishing a sharp knife was a thought one needed to get used to. But that was the reason they were doing this.

The grown erythrocyte stepped forth to stand beside her boyfriend as he rose, taking her turn to address their students. "Now, today we're going to be joined by a few myelocytes, who are in training just like you. While U-4989 and U-1110 here will play the part of the germs, your task will be to escape and find one of the myelocytes, who we've stationed on this floor. As soon as you've found and reached one, you're safe. The myelocytes meanwhile will keep a lookout for you, ready to step between you and the germs."

"Any questions before we start?" No one lifted a hand, while a few kids shook their heads. "Alright."

The two neutrophils put on their green, bacteria-hand puppets, while AC got the children back on their feet, making sure there was enough room between them and the two other teachers. With their short legs the blast would need a bit of a headstart. "Everyone ready? Get set. Go!"

AC couldn't help but chuckle at how quickly the children dashed off, nearly stumbling over their feet. As he ran past, 4989 gave her a bright grin, before following them into the corridors alongside 1110, hand puppets raised and held in front. At least someone was enjoying himself.

AC followed at a leisurely pace to watch the exercise, hearing some of the erythroblasts scream around the corner. She knew that neither 4989 nor his former teacher actually wanted to catch any of the children; they would chase, staying really close to encourage them to find a myelocyte, instead of running off or hiding in a corner.

Hopefully, the exercise would work. It was one to the ideas the three of them had come up with in the past few weeks to increase trust into the immune system, with the added benefit of really showing the young myelocytes what their purpose was. Neutrophils were already more approachable than lymphocytes, probably due to being raised in the bone marrow, but it couldn't hurt to let them get to know the cells, who would one day have to depend on them.

Further up ahead a small group of erythrocytes suddenly came running around the corner, straight towards AC. 4989 was right behind them, hand outstretched, the hand puppet hovering over one of them. If he wanted to, he could just catch the child, but he clearly maintained the distance, that sliver anyway, on purpose.

It was at that moment that from another hallway three boys dressed in all white jumped into view, small prop knifes ready. AC stopped to watch; here we go.

"Germ sighted!"

The myelocytes let the other children pass, rushing at 4989. When the erythroblast spotted AC, she quickly lifted her hands, telling them to stop. They needed to internalise that neutrophils, immune cell, meant safety.

To her relief the children did stop running, looking a little confused at first. They turned around just in time to see two of the boys attack 4989. Interestingly the third remained right between the erythrocyte and the 'germ' as a second line of defense; it seemed like 1110 had done a great job instructing them.

"Die!"

One of the prop knives struck the hand puppet, causing AC to briefly flinch. Hopefully, Hachikyu's hand wouldn't hurt too much from this. The second got her boyfriend in the abdomen and in a real-life scenario would have probably cut a bacteria wide open.

4989 seemed to agree, as he overdramatically fell backwards, free hand grasping a pretend injury. "Ah! You got me!" he gasped, just before hitting the ground.

AC couldn't help but shake her head with a smile, amused at his silly performance and was delighted to see that the erythroblast were now standing by myelocyte covering them, curiously watching everything unfold. None of the adult cells yet knew if this would make a difference, but watching these children now, AC had a good feeling about this.

A few days later AC found herself training someone again, though not in the bone marrow this time around. She'd been assigned a reticulocyte, freshly enucleated.

Reticulocytes

Red blood cells that have already lost their nucleus, but are not quite mature yet, still possessing organelles. These organelles are expelled over time, as they develop further into erythrocytes. As long as they are in the bone marrow, reticulocytes can still produce haemoglobin, but lose this ability once they enter the bloodstream, where they reach full maturity within one or two days.

The young man, while attentive to her advice, was often distracted by all the new sights around him, fascinated by this whole new world to explore and understand. AC remember very well what that felt like; she still found herself learning new things, despite having been to nearly every corner of the body.

They had already finished their first round from the lungs and back and now during their second trip they found themselves in a side road deep within the abdomen. AC was leading him through small streets, showing her student how to navigate the smaller blood vessels and find the right capillary. The ceilings were particularly low in this area, and being a few blocks away from the main arteries, the two erythrocytes were pretty much alone. Until AC heard scratching noises from above.

It sounded like a cover panel being moved, and when she checked, 4989's head was suddenly right in front of her. Upside-down.

"Huh?"

"Surprise," he chirped happily, a big, silly grin on his face, before he kissed the tip of her nose, almost knocking her beret off.

AC blushed and though she loved him and how he showed affection, there was one problem. "Hachikyu?"

"Yeah?"

"I'm actually training a kohai right now."

"...huh?" 4989 tilted his head, apparently only now spotting the other red blood cell in her company, standing right behind her, and his eyes widened, cheeks turning pink. "Ohhhh! I'm so sorry!"

AC snickered, despite feeling just as embarrassed. "It's alright, but how about we pick this up later."

"Yes, yes, of course. I didn't mean to...woah!"

And he was gone as suddenly as he'd appeared. Looking up again, AC now saw 2626 above in the ventilation duct, who had clearly just pulled his friend back up by his legs. He waved at her with a grin on his face, bangs covering his eyes as usual. "Sorry about that," he told her. "We'll catch up another time."

"Yeah, see you guys later," AC replied, trying not to chuckle.

He put the cover panel back into its place, 4989 grumbling something beside him in the duct. She heard them moving away, waiting until it was quite above their heads once again.

AC cleared her throat, trying her best to avoid eye contact. "So that happened."

Her kohai was quiet for a moment, though eventually ended the silence. "You're with a neutrophil?" He sounded flabbergasted. It wasn't the worst reaction the two of them had gotten worse; Memory T's rant was still ringing in her ears. That man had no indoor voice.

She shifted her shoulders, fingers grasping the oxygen box in her hands a little tighter. "Yes, he's my boyfriend. Long story." Frankly, she wasn't in the mood to tell it to someone she'd only just met, her student, and AC silently hoped he wouldn't ask too many questions.

"Sure," her kohai mumbled. "Sorry, it's just..."

"Unusual," AC offered, smiling sheepishly.

He nodded. "That."

When he didn't follow up with a question, AC straightened her posture and took a deep breath. "How about we just finish our delivery; it's just a few blocks away. Maybe get some glucose afterwards."

Apparently he was just as eager to drop the subject, her suggestion visibly putting him at ease again. "Lead the way."

Their pace was a bit quicker as they continued, until the oxygen had been delivered and they were on their way back to the nearest vein. AC was certain that there would be more awkward moments of that kind in the future, plenty probably, but frankly 4989 was worth every one of them and more.

The countless parks across the entire body, the blood vessels leading through them not as busy as the main roads, with traffic going at a leisurely pace, while buildings were few and far between. At least when compared to the rest of the body. They were without a doubt AC's favourite variant of connective tissue and a convenient meeting spot. As usual she was waiting for 4989, having made herself comfortable on one of the numerous benches beneath the lush trees, but unlike most days, she wasn't waiting alone.

"You really don't have to be this nervous."

CT looked up surprised and put her tea down. "Is it that obvious?"

"A little," AC admitted, but gave the other erythrocyte a genuine smile. "But I'm glad you came anyway."

Her friend brushed a strand of raven hair behind her ear. "Look, I know that my fears aren't entirely rational, but...I can't push them aside just like that," she noted. It sounded almost like an apology.

"I get it; it takes time," AC assured her. "I mean it's not like 4989 won me over in a day; he really had to make an effort before I was ready and was comfortable talking with him."

"Even after he saved you?"

The auburn haired erythrocyte nodded. "As you've said; you don't overcome fears just like that. But I suppose it was easier with Hachikyu than it would have been with many others. He's really easygoing outside of battle. And caring." He'd been from the moment they met, even before they'd become friends.

CT seemed to consider her words for a moment, taking another sip of tea. Despite her friend's uneasiness, AC actually wasn't too concerned about today. Getting her here had been the difficult part. She was certain that 4989's nature, along with everything she had told her friend, would be enough to finally convince CT that neutrophils were more than bloodthirsty hunters.

Still, AC had been surprised when her childhood friend had approached her a few days ago, claiming that she had thought things over and was ready to give this a try. And 4989 hadn't needed any convincing at all; he'd only asked where they should meet. If anything he'd been ecstatic. AC loved how wholesome he could be.

"So, how long since you two have been more than just "good friends"?" CT suddenly asked, giving her friend a meaningful look.

AC almost choked on her own tea. "What?"

"AD and I came through the lungs shortly after the whole fungus incident. We may have seen you two all wrapped up," the other erythrocyte explained and then winked at her. "Called it, by the way."

They had been there? AC pulled at one of the strands framing her face. "Sorry I didn't tell you," she apologized. "I just didn't want to hit you with everything all at once." Making this whole meeting even weirder for CT had seemed like a bad idea at the time, but it sounded like her friend was fine with her now romantic relationship. Unexpected, but it put AC even more at ease.

"Thought I freak out?"

"Honestly, I wasn't sure how'd you react, so I don't know...wanted to do it step by step, I guess?" It sounded somewhat lame out loud, even to herself.

Thankfully, CT actually snickered a little. "So, this is the big step now, huh?" she asked with a shy smile.

"I suppose you could call it that. Thanks." And AC meant it. She loved 4989 more than anything, but she'd never wanted to lose her old, childhood friends. With FP gone, she was glad and grateful that CT was willing to change her mind, or at least willing to try. Clearly, she too didn't want to give up on their friendship, and it meant the world to AC.

The two only had to wait a few more minutes, before AC spotted someone in a white uniform coming their way. Exited, she all but jumped to her feet and waved.

"Hachikyu!"

He waved back, big smile on his face, a steaming cup in his other hand. CT got up as well, clutching her tea with both hands, and AC saw her taking a deep breath. After today things would be very different no doubt.

"Hope I didn't keep you waiting too long," 4989 greeted them brightly.

AC chuckled; for once he was remarkably on time. "Don't worry about it," she assured him.

He then turned to CT and extended his free hand, smile never faltering. "Hi, 4989; nice to properly meet you."

As CT timidly grasped his hand to shake it, AC could have sworn she felt her haemoglobin jump in her chest. This wasn't just the preservation of one friendship, no, AC was sure beyond a shadow of a doubt, that this was the beginning of a new one as well.

It was peaceful day and with not an antigen in sight Dendritic Cell used the time to get a few things done around his home and office. He had already swept up the leaves on the walkways surrounding his tree and had gone inside to make some tea, when a macrophage passed by and handed him an envelope. He thanked her and put it on the table for the time being, already knowing what it contained, before he quickly checked on the almost boiling water and went to the shelves where he kept the cytokines.

He had something for every cell he could activate, same as every other Dendritic Cell in the body. All these images, that had captures moments in the lives of millions, safely kept within the countless pages of his photo albums.

After a brief search he found the one he was looking for. Dendritic Cell placed it on the table and opened it, flicking swiftly through the pages. Almost every image showed at least one neutrophil and though to many they would have all looked alike, Dendritic Cell could tell each of them apart without even glancing at the numbers on their caps.

About halfway through he reached the right pages and finally opened the envelope. Within were a handful of photographs the green clad cell had eagerly anticipated, made by one of his many colleagues.

It showed a scene at the kidney falls, the immune cell recognizing the wall of water rushing downwards in the background. On the observation platform itself was U-4989, on his knees, in front of him a blushing, but smiling AC 4293. The neutrophil himself had the biggest grin on his face, as he held a self-made sign, which read 'Will You Be My Girlfriend' in bold characters. Additionally, he hid behind his back a box with a bow on top, containing what were presumably AC's favourite treats.

The other cells surrounding them looked very confused for the most part, but the happy couple didn't seem to pay attention to anyone except each other.

The same was very much true for the second and third picture as well.

AC 4293 had naturally accepted, upon which 4989 had put everything down and picked her up. The photo showed him spinning them both around, the two of laughing in unison, her feet well above the ground. Of course he'd stopped before they were both too dizzy, and the final pictured was of them embracing, sharing a heartfelt kiss, both smiling against each other's lips and faces flushed.

Dendritic Cell smiled, seeing them both so happy. He had to admit that these were some of the more touching images he and his colleagues had ever taken, especially compared to the embarrassing ones they loved to use to 'encourage' immune cells.

Humming a merry little tune, Dendritic Cell added these latest pictures just beside the ones he'd taken in the lungs of the two cells in each other's arms after the mycosis had been dealt with. Another page completed.

He was already looking forward to the next batch.

The neurons were transmitting signal after signal at a rapid pace, letting lightning dance across the myelin sheath covering the axons. Like every REM-phase, circulating cells with a bit of time on their hands had come to watch the colourful spectacle of the neuron-forest, the viewing area packed as usual. Not that it bothered U-4989.

High up in the marginating pool he had the perfect view. And even better, AC was sitting snugly on his lap, leaning against his chest. What more could he asks for?

They were making up for last time, the neutrophil hoping that today no emergency call would part them prematurely.

4989 had his arms around her, his chin resting comfortably on her shoulder, allowing them to be cheek to cheek. The both of them had also taken their gloves off, and though his eyes were watching the fireworks, his mind was more focused on the feeling of her bare hands in his own. Her membrane was so soft and felt just a little warmer than his own.

One of his hands wandered to her wrist, where his fingers brushed against the braided bracelet he'd once made for her and the tiny scars beneath it. Despite what the parasite could have done, what it had done to handful erythrocytes, a part of 4989 was glad it had given him the chance to meet AC.

Would they have ever met, if it hadn't been for that incident?

4989 liked to think that somehow, at some point, they would have met regardless. After all, 1146 and AE 3803 had been running into each other constantly, even during her first day at work.

He nestled his cheek against AC's, affectionately stroking her arm. She responded by grasping his other hand and intertwining their fingers; this really was so much better bare handed. The neutrophil felt AC turn her head a little, just enough to peck his cheek, making his mitochondria leap in his chest.

He loved her deeply, no denying that any longer. 4989 knew that as a leucocyte, a neutrophil, he was supposed to protect every cell of the body equally, and he would, but AC had changed one thing.

Admittedly, he'd never liked the idea of sacrificing himself; it was part of his duties, and he'd accepted that a long time ago, but something he dreaded, nonetheless. If need be he would give his life, but he wasn't as unhesitant as those, who had committed suicidal NETosis to defeat the E. coli, or 1146, who'd been willing to jump into stomach acid without a second thought for the sake of the body.

4989 wouldn't say that he was more eager to fall in battle, but now every battle meant protecting AC as well. For her he would die without any regrets. The neutrophil hugged her tightly; she meant the world to him, and he didn't want to live in one without her.

...

After the REM sleep, 4989 and AC headed down, taking a road through the nasal cavities. Normally, this would have been a detour, but there was one more place they wanted to visit before returning to their respective duties.

The two could hear voices and laughter, even while they were stuck in the crowd, and they quickly navigated their way through the other circulating cells around them. AC had to dodge a carbon dioxide box that almost hit her in the back, her fellow erythrocyte quickly apologising as she passed. But they were out.

By the side of the road, having made themselves comfortable at one of the footbaths, were 1146, AE, 2048 and 2626. All four of them were enjoying the hot water, along with tea and the steam buns one could buy at the regional shops. Upon spotting the approaching couple, the redhead waved to them excitedly, while 2048 held up a few extra cups they had set aside for their friends, making the two lovebirds smile.

Despite regularly seeing their friends, moments like this with all of them together, just spending some quality time as a group, were too few and far between for their liking. Today though, they had managed to get everyone together and they would make the most of it.

Neither 4989 nor AC knew what lay ahead and what the future would bring, but as long as they had their friends, as long as they had each other, they'd get through anything.

The End