Archive of Our Own

Their plane crashed.

Of all the shitty D-list movie tropes Katsuki had unfortunately been subject to in his life, this truly was the fucking worst. 

They landed on some chain of islands (of fucking course), which was lightyears better than floating aimlessly in the middle of the ocean, so Katsuki shouldn’t complain. He still did, loudly. It didn’t matter. Thanks to their circumstances, Deku was the only one around to hear it. 

If he shut his eyes for too long he’d remember the raw terror that had bolted through him as they began to nosedive (the panic in Deku’s impossibly wide eyes, the painful adrenaline that had him tackling Izuku out of the gaping hole in the plane, the screeching wind, the way his hands screamed from blasting repeatedly to slow their descent, until they were close enough to the ground that Deku could use Blackwhip to lower them safely; the out-of-body horror of watching the plane hit the water in the distance from their spot on the shore),

so he didn’t. Instead, he barked at Deku to find water while he looked for something flammable. 

Izuku squinted up at the sun, shading his eyes with a palm. “Kacchan, it probably won’t get that cold tonight.”

Motherfucker. “Stop questioning me, moron. There’s a sea breeze and mosquitos.”

Izuku turned to squint at him instead. “Why are you so calm. Or… I don’t know. Prepared.”

“Because we won’t be here long, stupid. The plane had a GPS, they know where it went down.” Hopefully. But Katsuki wasn’t going to think about the alternative. “And I used to read those survival books as a kid,” he added, to throw Izuku off any potentially-worryful scent.

It worked. Izuku brightened considerably, beaming. “Kacchan’s amazing!”

The island was, Katsuki begrudgingly admitted to himself, quite beautiful. Untouched by the hands of man. A wide beach of warm sand scattered with driftwood leading to a dense forest. Katsuki didn’t really like the look of that – who knew what wildlife thrived in the untouched parts of the world. But trees like that meant high likelihood of freshwater, and if they got out of here soon enough, they didn’t have to worry much about drinking dirt or germs or whatnot, because they could get on a course of antibiotics, or even get their stomachs pumped if it came to it, as soon as they were back. 

The sun beat down on them but it was okay. Neither of them were dressed for sun protection, having been on the way back from an overseas two-day hero conference, but that also meant they hadn’t packed anything valuable that was now drifting to the bottom of the ocean. They’d grabbed their backpacks on the way down anyway, so they had some snacks, two water bottles, Katsuki’s favourite t-shirt, Izuku’s favourite sweater. A laptop, which was useless. A treated hand towel, because Katsuki was a flight risk.

Katsuki squatted on the beach where the sand was dry, closer to the forest but not too close. He set up the driftwood he’d gathered into a little hut for a fire, stuffing moss and dead grass underneath. Izuku came up to him with giant leaves bundled in his arms. 

“We can sleep on these, Kacchan!” Izuku said happily. Dumbass probably thought this was a fucking island vacation. 

The leaves were good, though. Katsuki grunted and took them from him, helping Izuku lay them out on the ground by the driftwood pile. 

He looked up into the forest. “Did you find water?”

Izuku shook his head. “No, but I heard a waterfall. I wanted to come get you so we could check it out together.” 

Katsuki ruffled his hair, pleased. “Good job not being a moron.”

They trekked into the forest, twigs and leaves crunching underfoot. Katsuki kept a keen eye on the shadows of the branches, half expecting to be assaulted by a wild boar, or—

He ducked under a branch, holding the leaves up and out of the way for Izuku to follow. 

Or a leopard or some shit. That would suck. The air was thick and sleepy between the trees, which meant two things: one, it creeped Katsuki the fuck out, and two, there must be enough water nearby to lend to humidity. 

They followed the sound of rushing water until they made it to the waterfall, with about an hour or so left before sundown, if Katsuki had to guess. Izuku gasped in awe. It was pretty, although he knew the algae-covered stone to be deceptively slippery, and didn’t trust Deku not to slip and crack his head open climbing one. The water fell in torrents onto elevated rock and then trickled into a small lagoon, and Katsuki could see fish in the clear water. Too bad neither of them had the skillset to catch one. The middle of the little lagoon was dark, too dark, so it must be deep. Katsuki toyed with the idea of looking in, and changed his mind, shivering. 

“This is making me thirsty,” Izuku muttered, staring at the torrential water. Katsuki dug one of their two water bottles out of their pack and shoved it at him — it was half full, the other empty from the thirst compounded by scavenging in the sun, and the hike. Izuku took the water gratefully and downed half of it, offering the rest to Katsuki, who shook his head. “It’s fine, dumbass. There’s more right here.”

Izuku softened his stupid googly eyes at him and swallowed another mouthful from the bottle. They were grown men who spent their work shifts outside — they usually drank a lot of water. 

“Nitroglycerin is waterproof. Maybe you can explode some fish.”

“Kind of dark, nerd,” Katsuki said, and Izuku had the grace to look sheepish.

Katsuki tried to think about how that would work. He wasn’t a fucking chemistry major — he hadn’t even gone to college — so he had no idea what that would do to the safety of the water supply. The water looked too still for proper circulation to disperse the blast compounds. If he accidentally poisoned the water and Izuku died because of it, he’d cut his own hands off himself.

“Dunno how I could kill one without blowing it to tiny pieces,” he offered instead of any of that, and Izuku hummed. 

“That’s true. And I don’t know if any would be brave enough to swim near your hand once it was in the water, at least close enough to be caught in the blast radius. I guess we have more of an issue catching them than killing them. I could use Blackwhip but I’ve never tried that underwater, and if we try too much we might scare the fish away from swimming near the water edge. Do you think that could happen? I saw that in a documentary once. Something about, like, tainted territory. They get the instinct to stay away out of self preservation, just in case.”

Izuku continued muttering to himself about wildlife evolutionary habits while Katsuki crouched by the lagoon and watched the fish, letting the lilting soft tone hum in the background. Self preservation. Neither of them were any good at that, historically, not when it came to each other. And here they were faced with survival on an empty island, with only the other.

Izuku had gotten to the point of his rambling where his whirring mind stumbled upon something that made him emotional, and now he was sniffing something about baby birds. Katsuki straightened with a groan and a frankly comedic assortment of cracking joints, and swung an arm around Izuku’s shoulder as required, ruffling his hair. 

“…abandoned… Kacchan,” Izuku warbled, choked up. 

Katsuki shook his head, exasperated and secretly fond. “If we find any lonely birds, we’ll take care of them, okay?” 

Izuku wiped his eyes roughly, clearing his throat, well past becoming embarrassed by his tears. 

Not many people knew this, but Izuku didn’t cry the moment he was born like most. It had terrified Inko, who thought he was dead, but the nurses and doctors assured her he was healthy, that some babies just – didn’t cry right away. He did eventually, and all was well, but young Katsuki was always fascinated by this story, the elastic way Inko would tell it, the irony that mumbling, cheery Izuku had been born quiet. That he didn’t burst into the waking world with a declaration on his lips, hadn’t always had so much to say. 

He’d later think privately that Izuku cried so much for the rest of his life to make up for those precious first minutes when he was silent.

Katsuki steered Izuku back to the shore, wishing there was some shade over the water. “Try using Blackwhip in the water here. For practice.”

Izuku had brightened considerably on the walk back, distracted by about 400 different things and talking a mile a minute, but he seemed to lift even higher at the suggestion. “Kacchan is so smart!”

It was a bust. The waves were gentle, loping in lazily, but it was still a huge contrast to the practically still-water lagoon. Izuku couldn’t seem to focus properly, depth perception out of whack with the sun in his eyes and on his back on top of the new medium for his quirk. He was getting frustrated, so Katsuki stopped him. 

“Oi. Shithead. It’s okay.”

Izuku shook his head angrily, curls bouncing. “I don’t understand why I can’t get it!”

Katsuki snorted. “It’s a shitty environment to learn something brand new. Plus you’re not hyped up in battle or anything. It’s fine.”

It wasn’t, exactly, since Katsuki didn’t know how long they’d be there or how much food they’d need, but Izuku looked on the verge of a panic attack.

Izuku whirled upon him, eyes wide and worried. “What if we starve because of me?” Ah, there it was. 

“I should have gone on that internship with Tsuyu. I knew I needed water training but I figured it could wait because Gunhead seemed more beneficial. I’m so dumb, of course we should be experienced on all fields, we’re heroes. Even Kacchan can use blasts underwater—”

Katsuki had sloshed his way next to Izuku in the knee-deep water, and took the opportunity to smack him upside the head. “Hey. Fuckwad. The hell you mean, ‘even Kacchan.’” 

Izuku blinked rapidly. “I! I just meant—”

But Katsuki was teasing, and he was tired of Izuku having the audacity to beat himself up right in front of him, so he shoved Izuku into the water. Izuku landed on his butt with a plop just as a wave swept over his face, and he re-emerged with a gasp, looking like a lump of seaweed.

“Kacchan!” Izuku scolded, bedraggled, pout giving way to a grin as Katsuki bent in half in laughter. A stocky leg swept out and wiped Katsuki’s legs out from under him, so that he fell in the water next to Izuku too, and now he was sputtering while Izuku cackled. 

“This was a bad idea,” Katsuki admitted, loathe to air dry in the hot sun, to feel the salt left behind sit and settle like a second skin. 

“Aw, come on, Kacchan,” Izuku said, smiling at him like some kind of sea nymph. “Island vacation. We might as well enjoy it!”

Fucking called it. 

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They did try Blackwhip in the lagoon, since they really did have nothing to eat. They were there for hours – stabbing into the water with spikes of Blackwhip didn’t work, the silvery fish too quick, Izuku’s aim too off no matter how many times he tried. Any aquatic life retreated to the deep sector of the lagoon if one of them even hinted at stepping in the water, so corralling was a bust. Izuku had to take multiple breaks, Blackwhip refusing to manifest if overused, especially outside of battle. They ended up with Katsuki laying on his back by the water’s edge, tossing and catching a stone, while Izuku tried one tactic after the other. He was on Strategy #4, keeping Blackwhip still until a fish came close enough he could twine a tendril around it and pull it out of the water, when–

“Kacchan!”

Katsuki shot up at Izuku’s breathless, excited call. He grinned. The bastard had done it – there was a single, violently thrashing fish dropped on dry land by Blackwhip, Izuku’s flushed face behind it. 

Izuku was oddly silent. Katsuki looked up– oh. 

Izuku’s eyes were wide, too wide, as he watched the fish flop up and down, side to side, choking and desperate and screaming the only way it knew how. He looked a bit horrified.

Katsuki felt a bit like an awful person, to not care that much, even if he was only simply capable of not thinking too hard about it. “It’s the same as eating it any other day, nerd,” he said, not unkindly. 

Izuku finally blinked, once, eyes flickering up to Katsuki for a second before returning back to the suffocating fish. “It’s not, though, is it,” he said. His eyes filled with tears, abruptly. “Kacchan, put it back.”

What– “Izuku,” Katsuki tried. His heart twisted painfully against his will. There was a big difference between stupid Deku tears, and actual pained tears, and Katsuki much preferred the former.

Izuku was shaking his head nonstop like he could ward off whatever guilt was welling up in him by sheer will. “Put it back,” he choked out, eyes never leaving the life seeping out in front of them, “We can’t kill it, Kacchan, look at it, I– we’re killing it.”

Katsuki looked down. The fish flopped feebly. “It’s too late now, Deku, it would just die anyway. Oxygen poisoning.” He wasn’t 100% sure this was true, but he doubted Izuku would want to listen about prioritizing lives in his state, and they really needed to eat.

Izuku glanced at him as his eyes widened further, somehow. “Too late,” he whispered, pitch rising on the last word like a half-baked question, mouth trembling.

Shit, don’t cry, don’t cry, don’t cry– “Fuck,” Katsuki said, intelligently. 

“Sorry, I’m— sorry,” Izuku muttered, wiping his eyes roughly. He turned back to the lagoon with an odd set to his shoulders. “I’ll get— Kacchan needs to eat.”

Oh, hell no. Something vile and violent twisted up Katsuki’s gut, and he wanted to vomit. “Oi. This is enough for now. Get over here before I kill you.”

“It’s not enough,” Izuku said, eyes on the water. Katsuki didn’t like the blankness in them. 

“It’s fine, nerd. I’ll just explode the fish for more, we’ll take the risk.” As in, Katsuki would consume potentially poisoned fish while Izuku ate the clean one, and hope his body’s natural resistance to whatever the fuck was in his sweat extended to his digestive system. And if he didn’t keel over and die, maybe they’d consider Izuku trying them too. Maybe. 

Izuku trudged over to where Katsuki was standing, fish wrapped in a big leaf, and Katsuki could see some minute invisible weight had left his shoulders. 

His heart twinged a little. Damn nerd. 

Izuku had always been like this. Soft. Not necessarily physically, but his bleeding heart was clearly squishy to the touch, in stark contrast with Katsuki’s more practical mentality. Perhaps it came from, or lended to, their differing priorities— Katsuki wanted to win, and if that meant saving everyone, he would do it and be the best. Izuku wanted to save everyone, and if that meant winning and being the best, he would do it. 

He’d never even killed anyone, in his three years of being a hero; never, except for one single time, when Katsuki was involved. Because Katsuki had been involved.

Inko had taught her son to value all life, and so he did, because he was precious like that, and now here he was sacrificing himself for Katsuki again. 

Katsuki had never really purposely killed anyone either. But he would, if it came to it. He’d do a lot of terrible things for Izuku. 

Perhaps killing someone together absolved them both of the sin. Perhaps it only doubled the weight. 

Whatever the case, Katsuki was not going to sit here and watch Deku’s big eyes go all sad watching something die, or go blank while he took it upon himself to kill it. Katsuki would rather starve. But Katsuki starving meant Izuku starving, so it looked like they would just have to take calculated risks until someone got here to take them home. 

Katsuki crouched and stuck his hand in the water, waited until the fish were no longer suspicious of it and one or two were within blast range, then let off a controlled explosion. He knew the flammable elements of his sweat were insoluble in water, and would thus explode, but he didn’t know the physics of the new underwater blast radius, or where the waterlogged heat would be enough to kill a fish. Katsuki didn’t let a big enough explosion off to make a big splash, since he didn’t want to terrifying their potential food. He was making a lot of guesses, here. But after a couple moments, a fish bobbed to the surface on its side, and Katsuki sighed, relieved. 

They had food for the night. Izuku was looking better, mumbling about liking plain fish anyway and something about fire starters. The sky was clear. Maybe they’d really be okay.

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Katsuki was beginning to think maybe they would not be okay.

It had been too many days. Just five, actually, but he and Izuku were Pro-Heroes, accustomed to keeping their bodies in top shape, which meant eating a lot in a day to match their workout routines. The cut to zero was getting to them. They’d had some biscuits on the plane before everything went to shit, and they hadn’t even been good, so Katsuki had given his to Izuku. 

Katsuki would give his left arm for some shitty airplane biscuits right now. 

The fish had learned fast for some fucking reason, so by the third day of setting off careful explosions in the water to catch food, the water edge was all but devoid of edible marine life, all the fish having retreated, presumably, deep into the depths of the creepy fucking dark hole in the center of the lagoon. Katsuki had even dared to venture out to it, bracing against shudders at the endless darkness below him, and tried to catch fish from there. But no dice— either his body treading water scared them away, or his controlled explosions couldn’t reach where the fish had gone. Katsuki still didn’t want to risk poisoning or blowing up their only water supply, so he gave up, and Izuku took a turn fishing. No luck. 

That was two days ago.

Hunger was a funny thing, a scraping ache, persistent and relentless. Annoying. Izuku was one of those fucked up people who could ignore their hunger, a habit probably developed from years of distractedly skipping meals, but Katsuki had always listened to his body to keep himself healthy. He wasn’t used to this, outside of rough missions. Missions that never involved being beat down by a tropical sun in unison with a depletion of food. It goes quiet, after a while, Kacchan, Izuku had told him, when Katsuki asked why he didn’t seem to be wracked by hunger pangs like Katsuki was. 

Katsuki didn’t really want to ask how he knew that, why he sounded so used to it. He resolved to keep a closer eye on him once they got back, though.

They’d taken to exploring the island in search of food sources, and were currently resting after having trekked for most of the day. They had to keep a balance — saving energy, and using it to find food. Gambles and risks.

One thing survival books had left out — nothing mentioned how they’d get so fucking bored. There was jack shit to do on an island once every necessary expenditure they could manage had been established. 

It was near midday and they were lazing under a cluster of palm trees, Izuku mumbling to himself, Katsuki letting the hum of it lull him to sleep. He hoped a nap would distract him from the restless hunger that had set up camp in his entire torso. 

He dozed off for a bit, too hungry to really relax. Giving up, he tipped his head to the side to look at Izuku, head rolling on the flat rock it was laid on. 

“Nerd.”

“Hm.”

“Let’s do something.”

“Like what.”

“I dunno. Do any of your quirks work right now?”

Izuku had told him, once, that Blackwhip actually took a lot of energy to make and control. It’s not mine naturally, Izuku had explained, so no matter how much he practiced it still took a lot of effort to use. That’s why it’s easiest when I’m emotional, he had added thoughtfully. Without adrenaline it’s really tiring.

Blackwhip materialized weakly, short bare wisps with little form. Izuku let out a shuddery breath and gave up. “Sorry, Kacchan.”

“‘S fine, nerd. Not your fault.” Not anyone’s fault but the stupid storm that blasted their plane out of the sky. How does that even happen? Katsuki’s head hurt. He reached for the water, then changed his mind and held it out to Izuku instead. “Drink.”

Izuku looked at it blearily. “I have to pee.”

Jesus Christ. “Then pee, idiot.”

Izuku hobbled a good distance away. To a different spot than they had been using, it looked like, deeper within the trees. He passed out of Katsuki’s sight and Katsuki clenched his eyes, his jaw, and his fists at the violent urge to go after him, keep him where Katsuki could see. It was to this tensed form of Katsuki that Izuku returned, hopping a bit in excitement. 

“Kacchan! I found something!” he cheered, notably weakly, grabbing Katsuki’s arm to pull him up and in the direction he’d come from. “Come look!”

It was a deceptively blessed fruit tree. Deceptively, because it was perched inconveniently in a mess of sharp rock, roots clawed tight around a particularly large, jagged boulder, squashed into the rockside about 20 feet up from the ground. It almost looked like the tree had grown out of the boulder, as if its roots were crawling out of the cleft to slowly drag itself out of a womb. The rubble below looked nasty, rocks cut in odd shapes with lethal edges and thorny plants growing in the spaces between. How did it even grow there? The rock hunched over the leafy part of the tree, crowding it so the little green-yellow fruit hung over the rubble below.  Meaning one of them would have to climb the tree and reach precariously over the death trap below to pick any fruit. 

Was it worth the risk? Katsuki’s stomach rumbled, and he winced. Katsuki would have to be. 

Izuku was eyeing the space between the jagged rock and the little fruits. He squared his shoulders. “I’ll do it. The branches might hold me. I’m lighter than you.”

“Are you?” Katsuki always figured their muscle mass balanced out. 

Izuku was curiously pink. “Yes.” 

Huh. Katsuki didn’t know that. “I’m taller. I’ll do it.”

Izuku pinked some more and shook his head stubbornly. “You can catch me if I fall. I don’t know if I can do the same.”

Bullshit, in usual circumstances, but Izuku was weakened by hunger, and he was right. Katsuki’s upper body strength was by far more developed, and even in his weakened state he had a better chance of spotting Izuku effectively than vice versa. 

He didn’t want to risk it. Those rocks looked nasty, and any circumstance that put Izuku at risk of harm made Katsuki want to rip his own teeth out. 

Damn, but they were so hungry.

“I’ll do it,” Izuku repeated. 

Fuck.

They stepped carefully around the broken rock in a painstakingly complicated path of least harm, mindful of sharp edges and thorns and what would happen if they fell. Katsuki gripped Izuku’s bicep in one hand stubbornly, pretending to just be pulling him forward. The nerd was clumsy as hell on a good day, let alone when shaky and famished. And maybe Katsuki himself felt more balanced, knowing Izuku was upright. 

There was a convenient section of the boulder with a less severe slope than the rest, so they removed their shoes and shuffled up carefully with shaking fingers and scrabbling feet. 

They appraised the tree with a critical eye. The fruit really were too high up to knock off with any stick they could procure, and seemed firmly stuck to their branches anyway. Katsuki sighed. Dammit.

Izuku climbed up the trunk with more effort than it should have taken, but in typical Izuku fashion he managed with no complaints, and with Katsuki posed under him in case he fell, stress lining every inch of his body.

When Izuku snapped the first fruit off the branches, he cheered, and Katsuki whooped (in relief, and a bit of pride). “Eat it,” Katsuki ordered just as Izuku made to toss it to him.

“Kacchan—”

Katsuki had expected his whine, and had cleverly put up mental barricades against it preemptively. “I don’t wanna hear it. You climb, you eat first.”

Izuku was scrunching his face at him, which was about as threatening as a stare-off with a chipmunk, and looked tempted to defy him and throw the fruit down anyway. As if Katsuki wouldn’t immediately lug it at his big stupid head, fall risk be damned. (He wouldn’t.) But in a landmark win for Katsuki in his lifelong trial against Izuku’s stubbornness, the other man caved. He peeled open his lips to take a bite, and—

“WAIT,” Katsuki said, panicked. Izuku froze with his teeth on the fruit skin. 

“We don’t know if it’s poisoned. Toss it here.”

This time Izuku really did scowl at him fiercely, scoff, and defiantly carve a bite out of the yellow fruit.

“Izuku...” Katsuki growled, incensed. Goddamn idiot.

“Fuck you,” the idiot said cheerfully, around the fruit. His legs dangled around the branch he was straddling, and he kicked his feet happily, humming as he chewed. “It’s good. If I don’t drop dead we’ll be set.”

Please don’t joke about that, something weak in Katsuki begged fiercely. He kept his mouth shut, and opted to glare at Izuku instead. 

Izuku reached up and snagged another, sending it Katsuki’s way. Katsuki took a bite without inspecting it. If something happened to Izuku, it should happen to Katsuki.

The fruit was fine. Half the size of his palm, a little gummy, liked to hold onto itself and Katsuki’s teeth while he chewed, but edible. It did nothing to fill the gaping hunger in his navel, the roils and rumbles and ache. They needed a lot more, more than what was in reach. 

Izuku tossed down a few more fruits, stopping and eating with swinging feet as he went. Katsuki didn’t move much, watched Izuku like a hawk while each bite dropped into his own yawning stomach like pebbles in a lake. 

When Izuku cleared the branches he could reach, they’d each had three, with four more set aside on a flat-ish rock for when Izuku had both feet on the ground again. It wasn’t enough, and they both knew it.

Izuku chewed his lips and looked around, muttering to himself. It gave Katsuki a queasy feeling in his gut completely separate from the hunger. 

“Oi. ‘Zuku.”

Izuku hummed at him and looked up, to a more precarious branch further out, over a pile of jagged, cruel-looking stones, ranging from the size of his head to the length of his body. 

Katsuki couldn’t stand under him there. “Absolutely not. We’ll eat what we have and come back later with a better plan.”

“It’s fine, I got it,” Izuku said, scooting up the branch, spine elongated as he angled himself to pick the fruit.

Katsuki was hit with a sudden stab of panic. “Deku. Get down from there.” His feet were sunk a little in the pile of rocks he was standing in. If Izuku slipped right now, Katsuki wouldn’t be able to catch him.

“I can get it, Kacchan,” Izuku insisted, reaching. His legs were wrapped right around the branch, one arm outstretched. Katsuki, against his will, started picking his way through the ridiculously sharp rocks, wincing. The nettles hurt like a bitch on his bare ankles and shins. He wasn’t close enough, he wasn’t—

“Izuku, get down right fucking now, I fucking mean it, I swear if you don’t—”

“I got it,” Izuku said stubbornly. He shifted just slightly to stretch his fingertips out.

It happened so fast. So sudden that Katsuki barely had time to leap desperately forward with his quirk, palms screaming, to tackle Deku out of the air before his brain splattered on the rocks below.

He didn’t quite make it.

Izuku gave an inhumane cry of pain as his leg hit a rock, having curled in the air to minimize damage and landed shin-first before Katsuki scooped him out of the air and hurled him onto softer land. He wished he could have carried him, laid him down gently, but his hands could barely sustain enough explosion to fly him without passing out from the pain. 

Fuck. Fuck fuck fuck.

Izuku muffled a scream, head thrown back, pain overtaking his face. Katsuki wanted to berate him for playing it down, but at the same time he was incredibly selfishly grateful, because he was pretty sure hearing Deku cry out in pain right now would snap the last remaining thread he had to his sanity. 

God, he could see white peeking out in the messy, bloody exposed muscle of Deku’s shin— was that bone?

“Shit, shit, shit,” Katsuki muttered, pressing on the wound. He needed a flat surface. He reached for his backpack, pulling out the laptop. Izuku was shaking with repressed screams, tears running silently down his face. Why would he hold back from crying vocally now, when he spent every other day in his life quick to tears? It was pulling at Katsuki, which pissed him off, because he very obviously had bigger problems. Fuck, why didn’t they travel with first aid kits, they were heroes- 

“Kacchan,” Izuku wheezed, faintly, “The backpack strap.”

Katsuki whipped his head back wildly and saw what Izuku meant – the wide buckle adjustable straps could tighten far more than simple tying of cloth. He ripped the left strap off furiously, tying the ends together and pulling the loose end until it was taut, applying constant pressure to the leaking wound.  

Fuck. Shit. This was bad. 

Izuku was catching his breath, body taut, eyes glazed with pain. “It’s fine, Kacchan,” he managed weakly, and Katsuki wanted to kill him.

“Can you shut the fuck up,” he snapped, then squeezed his eyes shut, “Sorry, sorry, I’m— fuck, Izuku.”

Izuku tried to smile at him, and it almost worked. At the very least, it calmed Katsuki enough to clear his head a little, and he lifted the wounded leg into his lap, elevating it. The bleeding slowed, and so did Katsuki’s heart rate.

“We’re gonna have to use the water to clean this,” Katsuki muttered, calculating the trip time and their resources, “I’m not leaving you here, so you’re gonna have to move, nerd.” They had wood on the beach for a splint. Splint, then clean? Or clean, then splint? Katsuki couldn’t believe he couldn’t remember.

“Clean, then splint,” Izuku recited obediently, as if reading his mind.

Katsuki nodded, and reached under Izuku to lift him. 

“I can do it,” Izuku huffed, but he wasn’t the same adrenaline-crazed, idiot shit he’d been in high school, and no one sane could just break a bone and nearly walk on it, but Izuku still possessed some leftover crazy pain tolerance, apparently, because he hobbled up with Katsuki’s help with minimal screaming.

Katsuki’s head hurt. The stress was toxic, and now worry for Izuku’s condition was gnawing ulcers into his stomach. 

Katsuki paused not two steps into their journey, holding Izuku to him. “Wait. That water isn’t clean.” He looked down at Izuku, stricken. “It’ll get infected if we wash it.” 

Izuku’s face twisted some more. “How bad could it be?”

Katsuki was already shaking his head, looking out at the path back to the beach. “Who knows how many animals shit in there. We’re lucky enough it didn’t get us sick from drinking it.” He wasn’t going to risk almost guaranteed infection just because they were used to taking clean water for granted. Izuku’s open wound was a lot more vulnerable than their stomachs. 

By the time they made it back to the beach, Izuku had gone white with pain. Katsuki sat him down as gently as he could.

“My mom says saltwater is antibacterial,” Izuku offered weakly, laying his head back in the sand.

Katsuki grunted. “Salt and clean water. Ocean water is full of micro shit your body isn’t used to.” He glared down at the other man. “Do not go into any water body with an open wound, shitnerd.”

Izuku hummed, uncaring. Too uncaring for Midoriya Izuku, but Katsuki knew his leg hurt like a bitch, and tried not to worry about it. Fussing wouldn’t help him heal faster. Katsuki fussed anyway.

He made a perfect splint, because Bakugou Katsuki was the best at everything he did, and of course he had aced all his emergency medicine courses. Izuku mumbled notes while he did it, because he was a huge nerd, and Katsuki would never admit they helped. Partially because a mumbling Izuku was a conscious one, and Katsuki wasn’t sure what he would do if he was left here alone.

Not long after Katsuki completed as much first aid as he was able, the sun began to set beyond the waves. It sank slowly, dipping everything in pink-orange-gold. 

When the last dregs of light had slipped behind the horizon, Izuku took in a breath to speak, lips at a bracing slant.

“Shut up,” Katsuki said, preemptively.

“Kacchan—”

“I’ll keep watch,” Katsuki snapped, and Izuku shut his mouth. Katsuki didn’t mean to be short with him, but the stress was getting to him, grinding on his nerves as if sandpaper ran through his veins instead of blood. Izuku looked down, quiet, and struggled into a sleeping position. Katsuki hated himself for making him look like that. He smacked Izuku’s hand’s away from his leg and set it himself, looking up at Izuku to check if it was comfortable. Izuku wouldn’t look at him. It was like an ice pick to the heart. He brushed his hand over Izuku’s quad in apology, and Izuku shut his eyes. Giving up, Katsuki shuffled back to his spot, leaning against the rock.

Night fell. It was too quiet, the air too-big and empty without Izuku’s mumbling. He was too quiet. Every couple minutes, Katuski’s exhausted brain would insist that Deku was dead, he had died, he had slipped out of the world of the living as silently as he had entered it, that Katsuki foolishly thought he was only sleeping but he would actually never wake again he was gone, gone, GONE — he had to shut his eyes and focus on the sound of soft breathing next to him to force his heart rate to slow to an even moderately healthy speed. Katsuki tilted his head back against the rock.

In between counting Izuku’s breaths and the stars, Katsuki fell asleep. 

The next thing he knew, Katsuki was waking to indistinct pained noises coming from next to him. He shot up, panicked, and turned to find Izuku twisting and turning as much as he could while trapped in the cloak of sleep, face screwed up against some phantom evil, whimpering and quietly crying in pain and fear. Katsuki shuffled over on his knees, reaching out to shake him by the shoulder gently. 

“Izuku,” he tried, hesitant, unsure if it was kinder to let him remain unconscious. But the terrified look on Izuku’s closed-eyed face was hurting him viscerally, crying for him to wake him from his nightmare. If only Katsuki could save him from waking into one, too. 

“Izuku,” he called, louder, nudging him a touch harder. Izuku gasped as his eyes shot open, wide and unseeing, looking around wildly with just his pupils before slowly focusing on Katsuki. His face crumpled. 

“Kacchan,” Izuku sobbed. “It hurts, Kacchan.”

Pure despair pierced Katsuki’s heart clean through. He gripped Izuku’s arms in desperation. “Fuck, baby, I know. I know, I’m sorry, Izuku, shh, I’m here,” Platitudes fell off his tongue like sand, just as warm, just as useless. The pet name slipped out unintentionally, Katsuki’s soul forgetting its safeguards in panic, mind empty except for the need to comfort Izuku somehow, to lessen his pain. Katsuki would do anything to get him to stop sounding like that. He carded clumsy fingers through salt-sticky curls.

Izuku cried harder. “I wanna go home, Kacchan,” he warbled, delirious with pain and fatigue. He hunched into himself a little, seeking childish self-comfort, and in the process jostled his precariously set leg.

Izuku screamed. 

Katsuki’s hands instinctively went to his ears, eyes wide with terror, before he aborted the movement to push instead onto Izuku’s hips, holding him flat on the ground and still.

“Izuku, please,” he whispered, tears welling up himself, heart aching to impossibly much at the sight of his Izuku in pain. The other boy kept writhing, whimpering at the sharp agony it elicited and moving some more to rid himself of it, again and again. “Izuku, stop!”

Izuku stopped, shocked into sobriety at the choked desperation on Katsuki’s tongue. 

Katsuki closed his eyes for a moment to gather himself, breathing heavily. Something soft brushed his face, and he opened his eyes to Izuku staring up at him, mouth twisted, one scarred hand on Katsuki’s cheek.

“Kacchan, why are you crying?”

Katsuki huffed out a broken almost-laugh. Fuck. He knew his skin had been too warm— Izuku had a fever. He must be delirious. Katsuki felt sick, leaning into Izuku’s hand, taking advantage of his altered state of consciousness to soak in the touch he was craving, the touch he was sure could heal him, if he had any right to it. 

“I’m scared, Deku,” Katsuki admitted quietly into the night and into barely conscious eyes, so honest he got a chill from it. He shivered. Izuku’s eyes rolled back.

“Deku!” Katsuki yelped, cradling Izuku’s suddenly limp body in his arms. “What the fuck— Izuku!” 

He patted his face— oh. Izuku was crying again.

“Hurts so bad, Kacchan,” Izuku whimpered, and Katsuki’s heart broke all over again. “I’m scared, I’m scared, Kacchan, make it stop.”

Katsuki hated himself in that moment, for being powerless in the face of Izuku’s need. He’d done everything, his entire life, to build himself up into someone who could always win— and here, when Izuku needed him, he was useless. 

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Eventually, Izuku fell back into a fitful sleep. Katsuki alternated between dozing off and jerking awake in a panic, checking that Izuku was alive and not in worse shape than before. At one point, Katsuki woke up to Izuku shivering, and cursed himself. He shifted closer, mindful of his leg— was Izuku running warm? Katsuki pushed curls off a lax forehead with a gentle palm. Not quite feverish, but maybe getting there. 

Izuku mumbled sleepily as Katsuki placed a careful arm around his waist, unreasonably tense in the shoulders and jaw. Chill the fuck out, Katsuki told himself, it’s just for warmth. It’s for Izuku. He couldn’t help but feel like he was taking advantage of the situation, somehow. Maybe because his stupid fucking hindbrain was crowing in satisfaction, marveling smugly at how right Izuku felt in his arms. 

Especially when Izuku tilted his head in his sleep, seeking Katsuki’s warmth, one knobbly hand gripping his own shirt and the other clutching Katsuki’s. Katsuki maneuvered them ever so carefully, so as not to wake Izuku nor jostle his leg, holding his waist and moving his curly head to rest on his arm. For warmth, Katsuki reminded himself, heart clenching as salt-matted curls and quiet breathing tickled his skin. 

Another time, Katsuki woke to Izuku weeping.

“I’m sorry,” Katsuki whispered, like it meant anything, like the words had any use. I’m sorry for everything echoed in their ears, just as redundant, just as useless. 

Izuku’s breaths came shorter, now, and Katsuki’s brain nearly melted in panic. He knew Izuku had been asthmatic when he was younger and still quirkless. He’d gotten stronger and healthier in every way upon preparing for, receiving, and training with OFA. Perhaps the mitigation of his quirks had deeper consequences than they’d thought. 

Katsuki shouldn’t have let him get cold. It had hit his lungs, along with the wet air. Katsuki had gotten used to recklessness being Izuku’s only weakness, taken his physical fitness for granted, had forgotten what it felt like to worry about him for reasons beyond either of their control. 

Izuku had been a weak child. He wasn’t supposed to be weak anymore. But here his lungs were, failing him. Here Katsuki was, failing him. 

Why didn’t Izuku flee from him, like the fish in the pool? He had so often tainted their territory. There were bloody handprints all over their hometown, and no one to weep over Deku, the dying fish. Now Katsuki had to watch him lay at his feet and suffocate on air. 

“Fuck,” Katsuki spit for the umpteenth time. He kept the fire going, elevated Izuku’s chest, checked his wounds, felt his forehead. Too warm. Hours passed, or maybe minutes, or maybe days. Izuku’s chest rose and fell shallowly, shakily. Katsuki watched every one. Izuku dozed, flirted with sleep, constantly coughed himself awake. His skin simmered hot.

“If you die on me, I’m taking all your All Might merch. And… fuckin’… selling it on eBay. Horribly undervalued. Specifically to someone who won’t take care of it.”

The corner of Izuku’s mouth lifted a millimeter. His throat worked as if trying to say something, but when no sound left his mouth, he relaxed again, blinking blearily to set his eyes on Katsuki’s face. Par for the course, besides the silence.

Katsuki really, really hated the silence. Words spilled from his lips in an effort to fill it, clattering on the ground, too-loud and echoing. 

“I don’t know how you held up this long like you have. Like you aren’t even a little bit afraid.”

There’s a long period of relative silence while Izuku struggled to breathe from the inflammation in his lungs and Katsuki struggled to breathe from the crushing weight of listening to it.

A wheezy, too-short inhale. 

“Because Kacchan is here,” Izuku croaked, finally, so faint Katsuki’s ears hurt in the strain to hear him, and heart hurt in the strain to not break. 

Izuku must have registered the lost look in Katsuki’s eyes, because he tried again, chest shuddering with effort,

“Kacchan’s with me. Don’t have to be afraid.”

Katsuki’s heart gave up, and shattered into pieces. He couldn’t help the sound that came out of him, quiet and guttural and heartbroken. This guilt, this terror was too much for him. He didn’t know where to put his hands.

“Kacchan,” Izuku was saying to him, so sweetly lost, so unthinkingly kind, “Kacchan, don’t cry.”

His cheeks were cold. They must be wet the way they only ever were before Izuku. No one else broke him down quite so intimately. 

(Izuku was born quiet. Katsuki was born screaming.)

His honesty could be found in the silences. Katsuki was very quiet when he cried, almost soundless, unlike Izuku who sniffed and choked and sobbed. He was quiet when he bowed his head, or held his friend’s limp body in his arms. He was quiet when he looked at Izuku. 

If Izuku died here, Katsuki might not ever speak again. Izuku would not die here, because Katsuki would not let him, but the thought struck a silencing fear through Katsuki’s heart, and his hands reached out on their own, petting through Izuku’s hair, palming his soft cheek.

Izuku leaned into his hand with his eyes closed. So openly trusting of the same hands that leveled buildings. That would bring down continents and bury oceans for him. That had burned him. 

A muscle jumped in Katsuki's jaw. He would hold Izuku gently to the end of his days, as long as Izuku was around to feel them.

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“—akugou. Bakugou!”

Katsuki shot up, heart threatening to race right out of his chest. Deku. Where was Deku?

He had to blink a couple of times to clock the red head in front of him. 

“Ei?” Katsuki croaked, dry throat scratching at it on the way out. 

“Hey, bro,” Kirishima choked, grin a mile wide, eyes teary. 

Katsuki groaned and laid his head back. “The fuck— you’re not with search and rescue.” He wouldn’t cry. He wouldn’t. 

The relief was like breathing air for the first time in a week, clean and cool and filling his lungs. His chest felt so light he could practically float away, the weight that might have prevented it completely off his shoulders. 

Kirishima rubbed the back of his head sheepishly. “Yeah, well, I couldn’t let my best buddies stay missing that long. And I could’ve helped clear a wreckage,” he added, quickly and a little quietly. Katsuki’s heart didn’t quite ache for him and their other loved ones, but it was a near thing. Would have been closer, if there was much room in his heart for anything other than—

“They’re looking over Izuku right now,” Kirishima rushed out, clearly noting the manic look that must have been present in Katsuki’s eyes. “Once he’s stable, we’re going.”

Katsuki finally fully relaxed into the cot. His chest wracked with a single, silent sob. If Kirishima noticed it, he didn’t say anything. 

He was a good friend. 

“Thank you,” Katsuki said quietly. Kirishima put a steady hand on his shoulder. 

“Of course, man,” he said easily. Like it had never been a question.

Katsuki rolled his head over to watch the paramedics fuss over Izuku. They weren’t panicking, so Katsuki didn’t either, even if every bone in his body screamed to go over there and take over, somehow, as if he’d know better, as if he was the only one who could take care of Izuku right. 

The doctor in the hospital briefed him. Perks of being Izuku's emergency contact. Asthma attack, like Katsuki had suspected, and pneumonia. The bone of his leg had splintered upon impact, meaning Izuku hadn’t just been suffering from the break, he’d had little bone shards inflicting sharp damage to the surrounding tissue the entire time, too. Nothing major in a world of healing quirks, but he hadn’t been. He’d been on an uninhabited island, in a world of just Katsuki.

Katsuki had a sneaking suspicion Izuku had thrown a fit down the hall, because a couple hours after Katsuki’s waking his bed was wheeled into Katsuki’s room with little fanfare nor explanation, and Izuku refused to comment.

His eyes were bright and awake. Katsuki drank him in like a man parched. Izuku’s curls lay on the white pillows like an aura, clean and soft-looking, and something about the mundanity of it made him smile. Peace finally nestled comfortably into his chest, settling quiet.

“You’re okay?” He asked anyway. He liked what the question always did to Izuku’s face.

Like clockwork, Izuku melted, shoulders releasing and eyes going soft. “I’m okay, Kacchan. They fixed me right up. And you, I assume.”

Katsuki nodded, relaxing into his pillows. Izuku eyed the door shiftily, then climbed onto Katsuki’s bed, criss-crossed on sterile sheets in front of him. A spitting image of endless days in their teen years. Katsuki bit back a fond grin.

“It was good to see Kirishima-kun. I missed his smile,” Izuku sighed. And it was very obviously a I-went-without-seeing-my-other-friends-for-a-week-because-I-was-stranded-on-an-uninhabited-island sigh, not a swooning sigh, but something ugly twisted in Katsuki’s stomach anyways.

“Might’ve been better if he had crashed with you,” Katsuki joked, aiming for a smile.

Instead, Izuku glared at him. It was more of a fierce pout, but Katsuki gave him points for trying. “Kacchan. I meant it. I wouldn’t have rather been stuck there with anyone else.” He blinked a couple times, blanching. “I-I mean. I’m happy it was you. I mean! Not that I’m happy it happened to you! Just, that, if it had to happen to anyone with me— like, if I didn’t choose them myself, and it just happened, and it had to— um. Maybe that wasn’t the best— I just—” Izuku stumbled over himself adorably. Katsuki watched him fondly and offered no help, because he had just been stuck on a deserted island for a gazillion days, and he deserved the silly joy this brought him. And the blush on Izuku’s cheeks. 

Izuku was still stuttering. He squeezed his eyes shut. “I JUST MEAN. I’m happiest being anywhere with you Kacchan! Over anyone else!” 

Katsuki felt the tips of his ears go warm, despite knowing what this fucking moron meant the entire time. He rolled his eyes. 

“I know, nerd. I got it the first four times.”

Izuku stuttered in indignation this time. “Wha— Kacchan! I was getting stressed!”

“Nerd,” Katsuki said again, because it bore repeating. “Dork. Moron. Dweeb.” 

Izuku was curiously pink. He scowled at him despite it. “Why can’t you be as nice to me as when you thought I was dying.”

Katsuki raised an eyebrow. “Sure. Whatever you want, baby.”

His own cheeks burned a little, but it was worth the way Izuku’s entire body seemed to go up in flames. He made a noise suspiciously close to a squeak and shoved both hands over Katsuki’s mouth, staring at him in wide-eyed horror and glowing cheeks. 

“ Kacchan. You can’t just— you can’t—”

Katsuki peeled the hands off his mouth with one of his own, grinning. “Hm? No?”

Katsuki could do whatever the hell he wanted. Izuku liked that about him, and they both knew it.

Izuku floundered. Eventually, he pulled his hands gently out of Katsuki’s and covered his own face with them, hunched over and groaning. Were the backs of his freckly hands red? Katsuki didn’t know that was physically possible.

Katsuki leaned forward and tucked his thumbs into the space between Izuku’s blushing hands, peeling them back to duck in and peek at his face. “Hello.”

Izuku made a strangled noise. Katsuki held his hands out just far enough to duck in and kiss him. 

God, if Katsuki had known how Izuku would sigh into his kiss, melt into him like warm honey, he would’ve done this ages ago. The sweet sounds gasped into his mouth turned the whole room gold. 

The hands in his trembled. Even this made Katsuki’s heart clench terribly, chest full with some emotion too complicated to name but adoring all the same. 

They made out on the hospital bed until a nurse came in and brandished her clipboard at them like a cane. Katsuki relented, if only for the twinge of nostalgia. He kept his hands on Izuku’s waist, though, because it fit so nicely in his palms, and no one could stop him. It was, like, medically necessary. Katsuki squeezed his fingers, and Izuku squeaked a little, cheeks a pretty pink. 

Yep. Professionally recommended. 

“If you make him get out of my bed I’m blowing up this hospital,” Katsuki said loudly. Izuku nearly blew a gasket, shushing him and flusteredly apologizing to the medical staff.

Hell, they knew he was kidding. He’d saved this very hospital from a shadow quirk just last month. But he hid a smile at Izuku’s fretting anyways, and pointedly ignored the knowing look two of the staff were sending him. 

A day later, they were released, bodies healed, quirks in full working order. The receptionist gave Katsuki a stink-eye, which was completely uncalled for. He had fully legitimate medical orders to be draped over Izuku like this. His arms getting in the way of the paperwork Izuku was filling out was an unfortunate but unavoidable side effect. 

“Will you or your boyfriend be needing assistance getting home, sir?” She asked Izuku sweetly. 

Izuku’s pen stilled over the paper. Katsuki could see his little ears turning red. He grinned, hiding it in green curls.

Izuku cleared his throat. “No, thank you, ma’am.” He only stumbled a little. Adorable. Katsuki was going to eat him.

Katsuki took the form and pen from Izuku and bent over the counter to fill it out himself, shooing him away. “Your handwriting is ass. Go get some water, I’ll do this and we’ll go.”

“Kacchan, I can—”

“Can’t hear you. Oh wow, I’m almost done. Sure hope my hero partner is HYDRATING before we leave for the LONG TRAIN RIDE HOME.”

Izuku scuttled away to the water dispenser. Classic. 

By the time he got back, Katsuki had finished his forms, having memorized all Izuku’s information years ago, and having always had significantly faster (legible) handwriting. 

“Your parents are picking us up,” Izuku mentioned offhand, sipping from his paper cup and shoving his phone back in his pocket. 

Katsuki tensed. “For the love of—“

“BAKUGOU KATSUKI.”

Katsuki turned around to go back to their hospital room. Or hell, another plane. Izuku grinned, holding him back by his shirt hem with a deceptively strong grip. “I love your mom.”

They both were smothered in tearful hugs (his dad) and rough squeezing (his mom). Katsuki got chewed the hell out while Izuku got a pat on the shoulder. Figures. 

Katsuki watched Izuku, blushing lightly under the attention from Katsuki’s dad, ducking with the hand affectionately petting his head and answering all Masaru’s questions with a little smile. 

“Interesting.”

Katsuki whipped his gaze to his mom, immediately suspicious. “What.”

She smirked from next to him, arms crossed. “Finally your ass in gear, huh.”

Katsuki huffed and looked away. His mom smiled at him, genuinely. “I’m glad, kid. He’s good for you. And you’re good for him, too.”

“Shut up,” Katsuki muttered, but he threw an arm around her shoulders, went back to looking at Izuku and his dad. She let out a shaky breath, the second time in his life Katsuki had ever heard her waver. 

“We were… it was terrifying, Katsuki,” Mitsuki said quietly. “But everyone had a lot of hope. More than we would have if you hadn’t been lost together.” She looked up at him. “Do you understand what I’m saying?”

Katsuki nodded, thinking of forest treks, of murdered fish, of dips in warm sand. Glassy eyes reflecting the stars. 

Izuku looked up, caught his eye; it felt like free fall. He came over, and Katsuki took his hand. 

“I get it,” Katsuki said, and he meant it.