Archive of Our Own

Leonardo gripped the edge of the table as yet another wet cough resonated through the lair. He couldn’t do nothing but hopelessly stare at the three figures on the other side of the clear wall.

The quarantine zone was built around Don’s lab and his workstation, the space big enough to accommodate four inhabitants. Both Leonardo and Master Splinter had been chased away from the lair while the rest of the mutant family built it, and were only allowed back inside once Donatello deemed the lair properly ventilated and all three turtles were inside the isolated zone.

The provisional quarantine was made out of acrylic glass just tall enough that their bodies would be visible, connected to sheets of various metal that covered the rests of the walls. It was supposed to be safer than fabric, but the construction looked like a cage and Leonardo hated it with passion.

A few days ago, the turtles had gotten sick. All of them – except for Leonardo.

And it was his fault.

Their sensors had picked up signals from the underground, on the path that led to the destroyed underground city. They were reluctant to go, which Leonardo understood. He wasn’t a fan of that place either. Quite the opposite if he was being honest. Nonetheless, they couldn’t just let possible danger roam around free. Anything related to the city below always ended with them getting hurt and Leonardo couldn’t stand by and do nothing when a threat was so close to his home, to his family.

They had found footsteps by the sensors, distinctively Y’Lyntian. Leonardo had made up his mind by then; considering their last visit ended up with wiping out the whole city, the possible survivors had more than enough reason to seek revenge.

He had decided to track them down. His brothers didn’t want to go but when he made it clear he would go with or without them, they followed him nonetheless.

He should have listened. He should have sent them home, should have insisted that he could do it alone.

The Y’Lyntian’s tracks led them into tunnels unknown to the turtles, right into a trap.

The Y’Lyntian was on the bring of death, lying on the ground. Leonardo was quick to draw his sword but his younger brothers rushed forward, and that was when the enemy struck. Faster than it should have been possible in their state, the Y’Lyntian scratched at each of the turtle, leaving bloody marks, before they got to their feet to attack the last remaining turtle. But Leonardo had swung hid katana the moment the person moved, the steel cleanly slashing through their body, ending the Y’Lyntian’s life quickly.

They hadn’t even made it back home before Michelangelo collapsed, followed by Raphael not so long after. Leonardo had crouched down to them, but Donatello had shouted “Don’t touch them!” so fiercely the older turtle physically recoiled, settling on watching him check on them. The two had woken up before the sewer slider got them back home and once they reached the door, Donatello had banished Leonardo from entering the lair and instructed Splinter to step outside and keep his distance.

“The Y’Lyntian infected us,” Donatello had explained once they were let back inside, conforming Leonardo’s fears. “Through the scratches. They’re shallow but it seems that it was enough for the pathogen to spread.”

It was a trap – and Leonardo led his brothers right into it. The Y’Lyntian would have died nonetheless, they just wanted to see if they could take them down as well.

It should have been him.

It was his decision, his leadership, his paranoia that had gotten his brothers sick, while he remained unaffected, completely healthy.

So here they were, days later, with no cure and him on the other side of the barrier that he so desperately wanted to tear down.

Donnie had run all the tests he could think of, but the sickness got worse day after day. With as much protection as they had available, Leonardo had returned to the dead Y’Lyntian to get samples of their blood and burn the body so the disease wouldn’t spread. He had brought Leatherhead to their home in hopes that his scientific background could help them, but it was to no avail for he was as lost as they were.

It started with headache and a fever that steadily grew higher and higher. The turtles got chills and grew weaker; yesterday they couldn’t even wield the cutlery. They’ve started coughing and today, colorful patches started appearing all over their bodies.

A beep from Donatello’s lab brought him back to the present and Leonardo immediately rushed to the glass divider. Donnie turned in his chair to look at the computer screen. Raph got up from his temporary bed, having to prop himself against the long desk as he took the few steps closer to look over Don’s shoulder. Mikey, lying on his own bed, opened his eyes as he curled more into himself. He closed them instantly, even the dim light making his headache worse.

The genius turtle blinked at the screen, the move slow. Leonardo watched his eyes zero in on the screen, then Don zoned out, and then he blinked again to force himself to focus.

Raph swayed on his feet.

“Nothing,” Don announced. “It looks like a combination of diseases but I don’t… There’s no matches and nothing is working.” He tried to hit the table in frustration but instead his hand fell down like a dead weight. “I don’t know what to do, I don’t… I’ve tried everything I can think of, everything I… I…” He trailed off. His pupils widened and he blinked a few times in a rapid succession. “I can’t see,” he whispered, panic rising in his voice. “My eyes – I can’t see the screen, everything’s so blurry, what’s…”

“Hey, it’s gonna be alright,” Raph tried to calm him down. “Let’s get ya to bed.”

But as Raphael took a step aside so Donatello could push the chair away from the table, his knees gave up. His head very narrowly missed the edge of the table and Leonardo shouted in alarm, rushing to the quarantine zone’s entrance without hesitation. He would have opened it, his own safety be damned, had it not been for a sudden strong grip on his forearm stopping him in his tracks.

Splinter said nothing, he simply shook his head no. Angry at the situation – but mostly at himself –, Leonardo broke loose of his father’s hold with more force than necessary.

“I’m okay!” Raph called, sounding everything but okay.

“Get to your bed,” Leonardo told him.

The two younger turtles stilled, as if just now realizing that he had been watching them. “Leo…?” Don started, uncertain.

“I’ll guide you,” the eldest assured him softly.

Donatello hung his arms. “Okay.”

He navigated his younger brother into his bed, making sure that Raph also did as he was told. Once all three of the sick turtles were laying down, Leonardo returned to his previous position. He had dragged the kitchen table and chair out here into the open space so he could keep an eye on his brothers and work at the same time. He had been doing his own research, going through various medical books April had brought him.

He had tried to reach Daimyo, hoping that his healers might have a cure, but the portal wouldn’t form no matter what, no matter how many times he tried. They were running out of options. Something had to be done, and soon. One look at his brothers was enough for everyone to know that they were dying.

Seeing them so weak, seeing them in pain… It should have been him on the other side of the glass. Life had never been fair to them, but his brothers had suffered more than enough.

You did this, his mind reminded him malevolently. You killed them.

No. No. They weren’t dead yet.

He rearranged the open books and notebooks on the table, putting one notebook on top of the pile. He focused on two names written on the last page.

Bishop.

Karai.

Two enemies, one worse than the other. They had no reason to help him. Shell, they would probably watch with vicious glee as his brothers slowly died, waiting for the right moment to strike him down too. But both of them had enough resources and scientists smart enough to figure out a cure – for the right price.

But what could Leonardo offer that humans wouldn’t be able to get on their own?

He paused as that one word – humans – switched something on in his brain.

Human medical expertise might have been useless so far, but Y’Lyntians were not humans. It was a different species with different diseases. He couldn’t get in touch with an Y’Lyntian, but he could reach out to another race that had suffered because of the Y’Lyntians.

Leonardo closed the notebook. He swung the sheaths with his katanas over his shoulders and grabbed two vials of the Y’Lyntian’s blood, one vial of each of his brothers’ blood, the notebook and a piece of crystal. The sudden, non-violent action caused their master to look his way, posture tense.

“Leonardo?” Splinter inquired. The warning was obvious.

Leonardo paid it no mind. He stepped to the wall dividing him and his brothers. “I’m sorry,” he started. The atmosphere shifted as four pair of eyes turned their full attention on him, surprised by the softness they hadn’t heard ever since they almost died on Shredder’s spaceship.

“I’m so sorry,” he repeated, louder this time. “This is all my fault. If I hadn’t…” He clenched his fists. There were so many things he wanted to say but couldn’t. “I love you. I’m going to fix it, I promise.”

“Leo, what are you…”

He didn’t stay around to hear the question, nor to answer it. He slipped past Splinter and rushed into the elevator that took him to ground level. The garage was filled with vehicles and devices, both functional and uncompleted. The Tech-packs were easy to spot and Leonardo quickly strapped his on his back. He secured the vials so they wouldn’t break even if he crash landed and headed outside.

The night sky was clouded, making it easier for him to climb onto the highest rooftop he could find and take off. He shot to the sky, through the clouds that hid his presence from any prying eyes. He gripped the crystal firmly in his hand, relying on it to guide him.

He flew for what seemed like an eternity. Every minute wasted meant his brothers were getting closer to a point of no return. Eventually, the Avians found him before he found them; a shout from above made him halt in his flight and look out, one hand on the hilt of his katana. Once he recognized the winged people, he put both his hands to his chest, palms shown in a universal gesture of peace.

It was a two-people patrol. They flew to his level and stopped a few feet opposite to him. “You!” one of them exclaimed in surprise, although not unkindly. “Sorry, I can’t remember your name. But I know you and the three others helped us. What brings you up here?”

“I’m Leonardo,” he announced. “And I came here to ask a favor of your people.”

The Avians frowned. “A favor? What for?”

“My brothers are dying,” he explained, trying to keep his temper at check, trying to remind himself that they weren’t purposely stalling, that he was an intruder seeking out their hidden home. “They were infected by an Y’Lyntian disease, and I thought that you might know how to cure them.”

Both of the Avians’ feathers rose at the mention of their race’s previous tormentors. They looked at each other, communicating without words, before they nodded. “Well I can’t promise we’ll be able to help, but we’ll take you to the Council.”

“Thank you.”

While the Avian City was as impressive as before, Leonardo paid it no mind, nor did he care about the looks other Avians were throwing his way once they made it inside the barrier. One of the guards separated, presumably returning to his work. Leonardo wasn’t surprised when Raptarr joined them before they reached their destination.

“Leonardo!” The Avian hero seemed to materialize out of thin air. “I didn’t expect to see you here.”

Not so soon, not him. Mikey would make more sense – but right now, Mikey couldn’t move, let alone fly.

“Me neither,” he admitted. “I wish the circumstances were better.” He paused. “My brothers send their regards, though.” They would have, had they known where he was going.

The graveness of his tone held Raptarr’s curiosity at bay until they reached the Council. Leonardo didn’t have to reintroduce himself, the Avian elders remembered the turtles vividly and so they welcomed him warmly.

“I apologize for imposing and possibly endangering you,” he started once the Council members told him to explain his request, “but I have no other choice.” He told them about what had occurred, about the trap and the dead Y’Lyntian who infected his brothers. Told them how none of the medicine they had tried worked, how serious his brothers’ states had become. Told them why he decided to seek them out, why he thought they might have the answers they needed. With every word he said, the Avians’ faces turned darker and darker.

“You were right in your assumptions,” one of the Council members said. “We know of this disease. This plague almost wiped out the Y’Lyntian population, in the ancient times. A cure was found, and while some cases of this disease appeared, there hasn’t been an epidemic ever since.”

“Do you have it?” Leonardo asked. “The cure?”

The Avian pursed his lips and Leonardo’s heart sank. He knew that look. “Yes and no. The cure is different for Y’Lyntians and Avians, so I assume it would have to be different for your brothers too. Especially considering your… origin.”

Their origin. The mutation. The reason they gained consciousness might very well be his brothers’ downfall.

He couldn’t let that happen. He wouldn’t. A cure existed, it was within his reach.

“Would you be able to adjust your cure to us? Based on your research and medicine?”

It had to be possible. If they could be infected, they could be cured, right?

The Avians looked at each other, coming to a consensus. “In theory. But from what you have told us, the disease has progressed so far that one wrong dose can be fatal to your brothers.”

“But not for me.”

The room fell silent. All eyes – both of the Council members and of onlookers who had piled up by the entrances to see what an outsider might want from them – were on him, their gazes heavy. Leonardo stared them down, not budging at all.

Another Council member’s wings fluttered. “But you’re not sick. Are you suggesting we infect you? That we experiment on you?”

“I wouldn’t call it experimenting,” he argued. He was more than willing to go through anything if it meant his brothers were going to live. “But yes. I’m healthy and I have the Y’Lyntian’s blood with me, so getting infected won’t be a problem.”

“That’s highly unethical,” someone else hissed. “It goes against all of our principles.”

Leonardo clenched and unclenched his fists. “Please,” he pleaded. How could they not get it? “Please, I’m begging you.” He pushed all of his desperation into his voice. He sank on his knees, his pride be damned. “I know I’m asking far too much. I’ll do whatever it takes, anything, just please – help me cure my brothers. Nothing else matters.”

They were all he had. He couldn’t live without them, and he wouldn’t. What was there to live for if his brothers weren’t by his side? Why would he be living if he were the reason his brothers were dead?

The crowd shifted, their wings nervously flapping. They were thrown off by his obvious desperation. The Council silently looked at each other, once again communicating without words.

A commotion rose from behind. “We’ll do it!” someone shouted.

Leonardo straightened up on his knees, looking over his shoulder. A group of four Avians stood there, one of them a few steps in front the others. “My team and I will do it,” the Avian repeated. “With all due respect, Council members, the decision isn’t yours. We are the ones who will do the research and the tests, not you, so the final word is ours. And we say we’ll do it.”

The Council wriggled collectively, their unease evident. Eventually, the decision was made: “Very well, Wintor. Your team can proceed. This hearing is over, everyone can return to their duties.”

Wintor nodded. Slowly, the gathered crowd started to diminish until it was only Leonardo, Raptarr and the scientist team. The Avians came closer while Leonardo got up to his feet, then the turtle bowed to them: “Thank you. I…”

“It’s no problem,” Wintor waved him off. “You helped us, now we help you. I get where the Council is coming from with ethics and malpractice and stuff, but the situation is dire.”

“But please keep in mind that we can’t guarantee positive results,” one of the team members urged. “We’ll do our best of course, but there’s just so many variables.”

“I appreciate the willingness to try.” And he meant it. If this didn’t work out, he would reach out to one of their enemies. Leonardo would have to be dead to stop trying to save his brothers.

“Well, we don’t have time to waste, let’s get to it!” Wintor exclaimed.

Together, they flew out of the Council building and to the research center, Raptarr going with them. The other Avians introduced themselves and Leonardo paid attention to their names and faces. Wintor, Berez, Grale and Alar. They were scientists who specialized in medical research. Their presence at his hearing with the Council seemed a little too perfect to be a coincidence, and when the turtle said so, Wintor explained that it was one of the guards Leonardo had met that sought them out. The guard thought that Wintor’s team might be interested to hear out Leonardo’s plea, and he was right.

They arrived to the lab. It was spacious, with equipment both similar and completely unknown to him. Leonardo had no doubt that it could rival Bishop’s lab in efficiency.

The four Avians went to work immediately. Their lab already had a built-in quarantine zone so they only had to slightly modify it. The divider walls were see-through and surprisingly didn’t muffle the sounds coming from the rest of the lab. Leonardo stripped of the Tech-pack and his gear before they ushered him into the secured zone. He was reluctant to let go of his swords, but Raptarr took them from him with a knowing nod. He handed his notebook to Wintor, telling him that he had copied Donatello and Leatherhead’s notes about their unsuccessful research. Grale and Alar concluded some basic tests on him – checking his body temperature, blood pressure, generally collecting data about his normal physiology.

He also handed them all of the vials and in turn they took samples of his blood. “For comparison,” Grale explained. “So we can see how everything reacts once we inject you, and also so we can see the difference between you guys’ healthy and sick blood.”

Grale then went on to telling him what was about to happen. His isolation was a precaution, they weren’t going to infect him just yet. First they wanted to test the blood samples, to minimize the danger of something going wrong. “I know it’s frustrating, but we’re working with limited…” he paused, searching for the right word. “Limited supply,” he settled on. “There’s a chance that the Avian cure could kill you on the spot, which is unwanted, to say the least. That’s why we’re going to do some tests on the blood samples first. It’s also why we need so much blood.”

Leonardo nodded. He didn’t like it, but his knowledge of medicine and science was limited. He trusted the experts. “Take all the blood you need,” he said. He was no stranger to what blood loss felt like and his vision had yet to start going hazy around the edges, so he knew he hadn’t reached his limit.

Hesitantly, he looked at Raptarr: “I know I’ve asked for so much already, but I need to ask for more. If I’m incapable once the cure is found, will you deliver it to my brothers?”

“You have my word.” The Avian then pursed his lips and crossed his arms over his chest. “I do have to ask, though. Your brothers aren’t aware that you’re here, am I right?”

Leonardo thought about his brothers’ eyes on him when he left the lair, about the sudden spark of clarity. “They might’ve figured it out.”

“Although they don’t know you’re doing this.”

The lab fell silent for a moment. “Probably not,” Leonardo admitted.

Raptarr signed. “I thought so. This doesn’t sound like something they’d approve.”

“I don’t need their approval,” he retorted, sharper than intended. Grale pursed his lips as he took out the needle from his hand, staying silent. Leonardo closed his eyes, taking a deep breath. “It’s the least I can do.”

“Wouldn’t exactly say ‘the least’,” Berez muttered.

Grale walked out of the isolation zone and handed Berez the fresh blood. Both of the Avians took a seat at one of the many tables and started their work. Leonardo recognized the microscope and the centrifuge, but that was about it.

Sensing Leonardo’s reluctance to discuss his decisions, Alar changed the topic: “Can you describe the progress of the disease again? With as much detail as you can?”

Leonardo did. He had memorized the course of the symptoms for each of his brothers perfectly.

“Looks like it progresses slower than for us or the Y’Lyntians,” Alar concluded once the turtle stopped talking. “And with how healthy your brothers were before, I think we have about five days.”

Five days before the disease becomes critical. Five days before the point of no return. Five days before they’re dead.

“Let’s do it in three.”

The Avian smiled at him, albeit a little sadly. “Gotta love a challenge.”

Wintor asked him about the specifics of their species and Leonardo answered as best as he could. He told them about the mutagen, about their origin, even about their upbringing in the sewers. “Don says that because we grew up in the sewers, our immune system is kinda messed up. Stronger, but that may be also due to the mutation.”

“It’s probable that it’s a combination of the two,” Wintor mused. “It might also be the reason why the diseases progresses slowly.”

“Donnie isn’t a medic – and he says so all the time – but he’s a scientist nonetheless. His discoveries are probably why we survived so long.”

Wintor waved at him with Leonardo’s notebook. “He seems brilliant. I can’t wait to meet him.”

Donatello would love it here. He had marveled at the Avian City during their previous visit, and he couldn’t stop talking about it on their way back.

Just one more reason why their places should be swapped.

He let out a deep breath and focused on watching the Avians work. He knew that usually it took months, if not years of research for humans to discover a cure, and even then it had to be tested and studied in case of side effects. But time was a luxury they didn’t have. Even with the Avian and Y’Lyntian cure existing and therefore providing some foundations to work with, how were they supposed to make it? Seeing his darkening face, Grale prompted him to voice his thoughts. Reluctantly, he did so.

“We’re lucky in this regard,” Grale told him, and when Leonardo shot him a disbelieving look that came across as menacing, he hurriedly explained: “It’s the sun crystals. We use them in research all the time and with them, we can speed up the culture growth and such.”

Slowly, Leonardo nodded. He had long since stopped questioning anything space-related. Various events in their lives disproved so many laws of science that at this point the only surprise was the fact that this effect was to the turtles’ profit. That didn’t happen often.

For a while, Leonardo simply watched them work. It was obvious that they were a team; each of them had an assigned seat in the lab. They moved around the space with ease, completing each other in fulfilling tasks. In a low voice, to avoid disturbing the scientists, Raptarr talked to him. He told him that he had been invited to join the Justice Force and Leonardo made note to say so to Mikey, knowing that his brother would be excited at the news. He appreciated the attempt at distraction, albeit futile, but with each minute that passed while he sat and did nothing, his frustration and anger grew. It was hard to keep his temper at check lately and now… He tried, he really did. He couldn’t let his anger win, couldn’t let them think he was angry at them lest they changed their minds about helping. The Avians were doing the best they could.

He was the useless one here.

This isn’t about you, he snapped at himself internally. Stop the self-pity and for once do something right.

If he needed to be quiet so the Avians weren’t disturbed, he would be. If they needed to bleed him dry to run the tests, then he would gladly bleed.

Grale did take some more of his blood. He also gave him some food to help refill the reserve. It tasted sweet, although Leonardo had to force himself to bite and swallow. He wasn’t hungry.

Hours went by. Leonardo checked his shell cell, even though he hadn’t silenced it so he would have known if his family tried to contact him. They probably tracked him, though. He showed Raptarr how to display a route to the lair on the shell cell, just in case.

The first few tests were unsuccessful. As feared, the Avian cure ended up killing the samples, although way slower than the Y’Lyntian cure. That one was an instant death of the cells.

He wasn’t really sure how long had they been there before one of them shouted in delight. It felt like ages. Leonardo sprung out of the adjustable seat at the sound, instantly on high alert. He watched as all Avians gathered around Berez to check the results.

“This seems promising!” Wintor called out. “Donatello’s research helped us narrow down some paths.”

Leonardo didn’t doubt that. “What does it mean?” he urged. Promising results was a very vague term in research.

“It means that we can discuss how to infect you.”

Leonardo perked up. He thought they would either inject him, but maybe it needed to be transferred through an open wound? That wouldn’t be an issue, he had more than one knife ready. “What’s the problem?”

The rest of the Avians went back to work, although it was obvious everyone was listening as Wintor started explaining: “The thing is, we need a cure, not a precautionary vaccination. The results may vary in different stages of the disease’s progression, so to be completely sure it will work on your brothers, you need to be as sick as they are.”

He froze. “But… We don’t have that time.” Because his brothers had been sick for four days by now. They couldn’t wait another four days and then some until they confirmed that the cure worked.

“We don’t,” Wintor agreed, way too calm for such big revelation. “Which is when the sun crystals come into play again.”

“Explain.”

Wintor passed the roughness in Leonardo’s voice without acknowledging it. “Berez used the crystals’ energy to modify a sample of the disease you gave us. I’ll spare you the science, the important part is that it can get you to your brothers’ state in a day or two.”

Well why didn’t he start with that? “What are we waiting for, then?”

The leader leveled him with a look. “It’ll cause you pain. More so than to your brothers due to the shortened time for all the symptoms to manifest.” He paused, searching in the turtle’s face, unsurprised when he found none hesitance. “And, if we don’t figure out how to heal you, you’ll die twice as fast, if not faster.”

That made Leonardo halt. He frowned, mulling over the words.

He didn’t fear his own death. While he would much rather stay alive with his brothers, he would gladly give up his life for theirs. Pain wasn’t a problem either. If anything, that seemed like a fitting end. The issue wasn’t him dying, but his brothers dying with him.

“If that happens, can you still find the cure?”

Their wings collectively fluttered. Berez sighed loudly. “That should so not be your only question.”

“I’ve already failed them once.” More than once. “I can’t fail them again.”

Wintor stared at him. “We can,” he confirmed at last.

Leonardo nodded thankfully. “Then let’s do it.”

Berez was the one tasked with injecting him. The Avian put on protective gear – gloves and mask – and stepped into the quarantine zone. Leonardo made himself comfortable on the chair, sticking out his arm.

“I understand your desperation,” Raptarr said from behind the dividing wall, “but when this is over, I’m telling your brothers. We might not know each other for long but I doubt they’d be happy to see you so eager to risk your life.”

Leonardo pressed his lips together, staying silent. If he was being honest, he didn’t care what his brothers had to say about this. It was his duty to protect them, and he would do so in any way possible.

The fluid in the syringe – the plague – looked harmless as Berez brought it to his arm and injected him. Leonardo watched as the colored liquid disappeared into his body. “Get ready,” the Avian warned him. “It should take effect in a few minutes.”

He smiled at him. “Thank you.”

Berez snorted. “You’re definitely the first person who thanked me for possibly killing them.”

Once he left, Leonardo readjusted himself on the chair. He brought his legs up to sit in a lotus position, palms resting on his knees as he closed his eyes to better focus on his body. He listened in on the sounds of the lab, trying to follow the Avians’ quiet words.

He knew it was coming, yet that sudden feeling of lightness took him off guard. He felt himself tilt to one side and he involuntarily opened his eyes, hands shooting down to center himself. His right hand completely missed the chair. Gravity won and he tumbled off the chair onto the ground as his vision went black.

The coldness of the ground woke him up a few seconds later. He groaned as he clambered up onto the chair, this time lying down. The chair reclined to accommodate his position.

“Everything okay?” Alar called out.

“Yes.” The word was a bit too loud, resonating in his head. What was the first symptom again?

Headache. Yeah, that sounded about right. Leonardo was prone to migraines, had dealt with them often through his life, and he could tell that this one was going to be intense. It started with a dull ache at the center of his forehead that quickly turned sharper and spread to the sides. It felt like someone tried to hammer a metal nail into his head.

Using two fingers, Leonardo gripped the root of his nose, then tried massaging his temples. Unsurprisingly, none of it helped. He laid there, focused on his breathing. Usually, when developing a migraine, he would go to sleep. But if the disease actually worked as fast as the Avians said, then sleeping wasn’t really an option. So, he tried to relax his body instead.

It took him a while before he noticed that the lab was unnaturally quiet. Quieter than it should have been. Blinking his eyes open, he looked in the direction of the Avians, unsurprised he couldn’t see anything but blurred shapes over the rainbow zigzagging across his vision. Figured an aura would manifest.

“You don’t have to be silent on my behalf,” the turtle called out.

“No need to make it worse,” Berez replied.

Leonardo huffed a quiet laugh. “I appreciate the sentiment, but I live with three younger brothers. You can talk as usual, it doesn’t bother me.”

Ninjas or not, the lair was never silent, even if one of them was sick or tired. They were quiet, sure, but never completely silent, and Leonardo loved that about their home and his brothers. Absence of noise meant something was wrong.

Besides, until now, the Avians talked during their work. The team had a routine, one Leonardo didn’t want to disturb for the sake of a kind but misplaced consideration. He smiled as the Avians hesitantly started talking; a whisper that steadily grew louder.

The fever sneaked up on him. He started to get warmer and warmer until he suddenly felt like he was burning alive. He writhed on the reclining chair, shifting from one side to another. He had no layers to strip off, had already done so before they started. But his skin was burning, the heat rising and melting all his thoughts. He swore he heard his brothers groan, smelt burning fur, his shoulder was throbbing, the heat kept on rising, rising, rising, they were going to die here –

Leonardo showed himself away, falling on the ground with a heavy thud, plastron first. Once again, the coldness of the ground shocked him enough to pry his mind away from the memories and into the present. He twisted his head, squishing his cheek on the ground, welcoming the chilliness.

The Avian lab. He was high in the sky but it in the Avian lab, not a rocket ship.

Out of the corner of his eye, he saw a figure kneeling by the dividing wall. Raptarr’s mouth was moving but Leonardo couldn’t hear a word over the buzzing in his head. He gave him a thumbs up that seemed to satisfy the Avian.

Making an executive decision to stay on the ground, Leonardo curled into himself. Comfort of the chair be damned, the floor was pleasantly chilly and it helped him stay grounded. He didn’t want to risk succumbing to a memory and losing it in front of others.

A shiver ran down his spine. He was still burning up but now he was cold and he had nothing to cover himself with. A blanket would be nice. Or maybe a heater.

The chill stopped, the warmth returned in full force.

And then it disappeared again.

Leonardo sighed. Never mind.

The chill came in waves, the constant and abrupt changes made him tired. His muscles ached, his head was spinning, his chest hurt.

He coughed, then coughed again. His lungs tightened as he tried to take a breath, only to end up wheezing. He twisted onto his shell, placing his hands on the ground so he could prop himself up. It took him longer than it should have to sit up. He curled his fingers as the world spun and tilted, but he leaned his shell against the chair to stay propped up. The pain in his chest eased momentarily, then it came back with more force.

It didn’t take long before his throat started hurting from all the coughing. He didn’t even try to keep his eyes open anymore. The scientists checked on him from time to time; knocking on the barrier, content when he gave single-word responses.

The chipped part of his shell itched. He felt a foreign presence all around, circling around him, drawing closer, closer.

He needed to move. Needed to get away.

Frantically, Leonardo tried to scramble up on his feet. His were eyes wide open as he searched for he danger he felt but couldn’t see, his vision still resembling a broken, pixelated TV screen from the aura.

His body was stiff from the hours he had been sitting there doing nothing. his legs felt like lead as he forced them to move. He gripped the edge of the chair, pushing up, but his knees buckled and he went down again.

No, no, he needed to get away. He couldn’t stay down.

He gritted his teeth, tried to bring his hands up. None of his limbs listened. He couldn’t move.

He couldn’t move.

His breath hitched. He had to move, he had to get away, he had to survive this to help his brothers, had to get to them, had to make sure they were safe. Where were they? Where was he? Why couldn’t he move?

How was he supposed to protect his family? He couldn’t even protect himself. Where were his swords? He needed them. He could fight this, whatever it was, if he just had his swords…

A loud bang resonated through the space. The turtle flinched, zeroing in on Raptarr.

Raptarr…? Why was he…?

Oh. The laboratory in the Avian City. That’s where they were.

He tried to take a deep breath. There was fire in his lungs, in his bloodstream, in his mind.

Everything hurt. Every part of his body ached. He felt weak, and that scared him the most. It was hard to convince himself that him being weak was what his brothers needed the most now.

Someone touched his arm.

Leonardo moved on instinct. His fist collided with a firm body, and while the punch lacked its usual strength, it still caused Berez to stumble back, his wings unfurling in surprise.

The turtle keeled over, barely managing to stop himself from hitting the ground with his face. He heaved once, twice, then threw up a mix of gastric juices, saliva and blood.

Leonardo was no doctor, but something told him that the blood wasn’t a good sign.

Berez’s quiet cursing confirmed his thoughts.

Wait, Berez. Right, he punched him. The constant forgetting of where he was might have been an issue too, but definitely not one Leonardo was going to concern himself with.

“Sorry,” he muttered. “Didn’t mean to.”

“Don’t sweat it,” Berez replied, then snorted. Leonardo was too out of it to understand what was funny about his words. Due to the still present migraine aura, Leonardo couldn’t see all of him, just the general outline of an Avian and a flick of an arm or a wing. It was enough to visualize where he was standing and what was he doing, now that the ninja knew there was someone next to him.

Berez’s eyes flicked to the vomit, then back to the turtle. “So this definitely isn’t good and we might have a problem if the first dose doesn’t work.”

“Then let’s… hope it works.”

“Has anyone told you that you’re kinda crazy?” Berez asked as he – slowly, so Leonardo could watch his every move – walked to the turtle. He didn’t wait for an answer, instead he scooped the ninja up in his arms and moved him back onto the chair.

Leonardo huffed, missing the chill of the ground. He was on the floor for a reason. If he falls from the chair one more time…

His attention shifted instantly once Berez took his hand, turning it from one side to another. Dark, brown, grey and black patches covered his hand. And not just hand, Leonardo found out in astonishment. No, they adorned his whole body, somewhere more, somewhere less. He hadn’t even noticed they had appeared.

It would explain why the flaming pain never went away though.

He frowned, searching in his memory. His brothers didn’t have the patches for the first three days of the sickness. “How long…?”

“About nineteen hours.”

It felt like longer. Like an eternity.

Hold on. Leonardo stared at him, forcing his mind to work. The number sounded weird. “That was fast.”

“Way too fast,” Berez nodded solemnly. It was supposed to take up to two days, not barely one. “I’m going to take your blood now, okay?”

“Why?”

“We went from your brothers’ blood samples when we started figuring out the cure, but we want to have your samples too – fresh from the source. I’ll take your blood now, and then later after the first dose of the cure has been applied,” Berez explained patiently while doing so. Leonardo blinked at him, hearing the words but having a hard time with understanding their meaning.

Whatever. They were the scientists, they knew what they were doing.

Once Berez was satisfied with the blood sample, he took a few steps back and took a bowl from a nearby table. He must have placed it there when he entered the zone, for the soup inside was still warm. “Eat,” Berez instructed.

Leonardo tried. He really did. But even if he overlooked the embarrassment of Berez having to hold the bowl by his mouth because Leonardo’s fingers refused to curl so he could get a grip, he barely managed one sip before he heaved again. His stomach lurched, the liquid irritating his insides. He pushed the bowl away, not willing to vomit again.

Berez sighed. “Worth a shot. I’ll be right back.”

Not like Leonardo was going somewhere.

The Avian was back before the turtle even noticed he went away. There was a syringe full of clear, light blue liquid in his hand this time. “This is a modified version of our cure. We ran tests on the samples you gave us and we have positive results,” Berez explained. “So with how quickly the diseases progresses in you, we’ve decided it’s time to test it on you.” There was an undertone of urgency in his voice, something anxious the ninja couldn’t place. “Once it starts working, I’ll take your blood again. It’s risky – we’ve already drawn so much.”

“I can deal with blood loss.” He had, in the past, and not once. The blood would refill eventually.

“If your brothers are like this too, then I take back my words about Raptarr’s praises about you guys being exaggerated.”

The words saddened him. “They’ve been through a lot,” the turtle muttered darkly. His brothers didn’t deserve any of this, didn’t deserve none of what happened to them. They shouldn’t know what it feels like to almost bleed to death, shouldn’t know what it feels like to starve, shouldn’t know what is feels like when your life force is fading away.

Berez said something else, although Leonardo didn’t hear him anymore. The Avian seemed to realize that, for his shoulders dropped and he took the turtle’s hand. The needle pierced his skin, the cure filled into his bloodstream.

Berez helped Leonardo lay down on the chair, then he walked away to give the cure time to work.

It only took a few minutes, and then in between one breath and the other, the fire in his lungs receded. After that, the other symptoms started going away. As he blinked, the rainbow spots disappeared, his vision clearing. The migraine dimmed into a dull headache.

Slowly, Leonardo relaxed on the chair. Then, because he was impatient, he pushed himself into a sitting position and swung his legs over the edge of the chair. When the world didn’t spin, he pushed himself up. “It’s working!” he called out, voice significantly louder than it has been.

Berez was already on the move. He entered the quarantine zone, but instead of joy, his face was twisted in alarm. “Sit down,” he ordered, then pushed him back when he deemed Leonardo too slow. He jabbed a needle into Leonardo’s hand before the turtle even managed to ask why the long face.

“What’s going on?” Leonardo demanded.

“It might be nothing.”

“What’s going on?”

Berez paused, carefully taking the blood needle from his vein. “Your infected blood – it’s different than your brothers’.”

Leonardo froze, staring at him wide-eyed. No, that couldn’t be. All of this was for his brothers, so they could get the cure for them. “What does it mean?” he urged roughly. “The cure seems to be working, so what’s the problem?” Would it not work for them? Was he unable to help?

“We’ll know more once we analyze this sample.”

It wasn’t an explanation. Berez didn’t answer any of his questions, just walked out of the quarantine. When Leonardo turned towards the rest of the scientists, they were pointedly looking into their devices, working. Leonardo gritted his teeth, knowing that he won’t get an answer out of them yet. Berez joined the rest of the Avians.

Making use of his returned strength, Leonardo paced the isolated zone. Raptarr stood by Wintor, talking too quietly for the turtle to hear. The turtle glanced at the shell cell the Avian held in his hand, then returned to walking, unable to stay still.

Blinding pain surged through him, sending him crashing onto the ground at once. His fingers curled as all of his muscles spasmed, his mouth opened in an aborted scream, no noise escaping him. One moment he was alright, the next he felt pain worse than before.

He felt his heartbeat in his ears, so loud it was deafening.

He couldn’t breath. He tried to will his muscles into relaxing, tried to get his lungs to spread out. His body didn’t listen.

He couldn’t move his fingers. Couldn’t call for help, couldn’t even blink.

The door to the quarantine burst open as Berez rushed inside, forgoing his protective gear. He pushed some kind of a mask onto the turtle’s face that forced air into his lungs. That one push seemed to be enough for his lungs to start working again and he gasped for air.

Noise came crashing down on him. The Aviants were shouting, Berez kept asking him if he was alright as he moved the inhalator away, shining a light into his eyes.

His heart was still beating faster than it should, like it wanted to jump out of his chest.

Leonardo blinked. “I can’t move,” he croaked.

Silence fell over the lab.

“Just a few more minutes,” Berez whispered, desperation written all over his face. “Then we’ll know for sure.”

It didn’t seem like he was talking to Leonardo.

Scared of what he might say, Leonardo stayed silent. Minutes ticked by until something beeped. He heard rapid movements, something opened, something closed, then crashed. Silence for a second.

Then, cursing.

Berez’s face fell.

His heart skipped a beat. It didn’t work. It didn’t work, something went wrong, his brothers will die and he won’t be there with them to say goodbye, won’t be there to hold them, to tell them he loves them.

He failed.

Tears gathered at the corners of his eyes.

“Raptarr, take the vials and go!” Wintor shouted.

That… That didn’t make sense. But Raptarr apparently did as he was told, for when he appeared in Leonardo’s field of vision, he had three vials in his hand and a shell cell in another.

Inside the vials was the same clear blue liquid.

The one that paralyzed him.

Terror flooded him. What had he done? How could he be so stupid as to trust someone again? How could he doom his brothers with his decisions again? He should have known better. Instead, he invited the Avians into their home, and his brothers were going to pay for it.

He knew this was too good to be true.

He blinked, the tears streaming down his face. Anger mixed with grief. “My brothers…”

Donnie. Mikey. Raph. He hadn’t been the greatest example of an older brother lately. He had distanced himself, snapped at them, yelled at them over nothing.

Will they die thinking he had abandoned them? Thinking he didn’t love them?

“They’re going to be alright,” Wintor said, appearing out of nowhere. He kneeled next to the turtle.

Leonardo glared at him. “I don’t believe you.”

Wintor stared at him, surprised by the open hostility, before understanding shone in his eyes. “I swear on the lives of everyone here that I’m telling the truth. Your brothers will be alright. It’s you that won’t be.”

Silently, Leonardo stared at him. Grale and Alar walked up to them, joining the rest. They all looked saddened, void of any malicious glee an enemy would have.

They were telling the truth, he realized. He hadn’t been mistaken when he trusted them.

“How?” That’s what he wanted to know. How could they heal if they were given the same cure? When he was unable to move, when he could feel his organs slowly shutting down?

Wintor’s wings hung down. “We messed up,” he admitted quietly. “The plague mutated in your body. What most likely happened is that the mutagen in your body reacted with the power of the sun crystals we used to alter the disease. The disease… It started changing, progressing faster than it should. After you were given the cure, we were able to see how it reacts to the disease from the samples of your infected blood. We figured out what was wrong with the first dose you were given and modified it. It will work on your brothers flawlessly, but when it comes to you…” The Avian trailed off. “The cure works, but not enough. It attacked the cells of the disease, it’s destroying them as it should. But the mutated ones keep on regenerating and breeding, and there’s too many of them. We’re working on a cure but I fear that’s it too late. Paralysis is the next-to-last stage of the plague.”

With death being the last.

The scientists watched him, waiting for the outburst, for the denial, for the screaming and begging that never came. Instead, the tears stopped. The blazing pain didn’t fade away, it intensified with each passed second. It left him unable to take anything but shallow breaths, it left him unable to move. His organs twisted and turned, his blood boiling.

Leonardo knew, with indisputable certainty, that he was dying.

Yet his thought were only on his brothers.

“They’re going to be alright?” he asked, desperately needing the confirmation.

“Yes,” Wintor nodded. “They will live.”

Slowly, the tension he had felt disappeared. They had done it, he had done it. His brothers were going to live, they wouldn’t pay for his mistakes.

“Good,” he breathed out.

“No,” Berez argued. “That’s not good, Leo! You’re dying.”

“It’s worth it,” he told him, sounding out of breath but way too calm for how fast his heart was beating.

He couldn’t feel his fingers anymore. His vision was blurry.

“Thank you.” Leonardo looked at each of them, trying to convey his gratitude with just his expression. “All of you.”

“You can thank us later,” Berez refused. “Once we heal you.”

Leonardo smiled. He was glad he decided to seek out the Avians for help. They were good people and he appreciated their work and effort. They kept their promise, they figured out how to cure his brothers, and that was all that mattered. He regretted that he won’t be able to repay them, regretted that he won’t get to hug his brothers again, that he won’t see them heal and grow up.

But they were going to live, and that’s what mattered.

“I’m glad I came to you,” he told them sincerely. Blackness lurked at the edge of his vision, slowly seeping further. “Please tell my brothers…” Tell them I love them, he wanted to say, but his voice refused to work.

Darkness took his eyes, plunging him into nothingness. The sound of his own heart beating frantically filled his ears, drowning out any other sound.

Leonardo let the pain take him away.