This is a rough first chapter, but my brain's too wacked out to edit properly. XD I prewrote most of this in Whumptober (this was my long lost "Exhaustion" prompt that spiraled into 15K - yep), so I'll update twice a week! Hope you guys enjoy, and do RR.

CHAPTER 1:

Sometimes, Izuku felt like he had the worst luck.

From being born quirkless to eventually having a quirk that destroyed his body when he used it, he definitely wasn't part of the luckier half of the population. But every once in awhile, he caught a break. He had a great mom, amazing friends, got into the best school in Japan… some days were really good.

Today wasn't one of those days.

Izuku and a few of his classmates had gone to town on their Saturday off to do a little shopping and sightseeing. After a long week of training, it was time to relax a little. Eventually, Ashido had managed to drag them inside a jewelry shop to look around, though none of them except Yaoyorozu could afford anything.

Overall, Izuku was having a pretty good time. He hadn't bought anything but enjoyed spending the day with his friends.

That was, until a suspicious-looking customer at the cash register violently yanked the store clerk to his side. With an unfaltering expression of malice, he whipped a gun to the jewelry clerk's head, deadly serious.

"ON THE FLOOR, PEOPLE, OR BODIES WILL START DROPPING!"

Taken aback at the violent turn of events, no one moved.

"FINE, SO YOU WANT THIS GUY DEAD? MOVE IT ALREADY!"

His hostage looked terrified, whispering a litany of pleas for mercy. The villain ignored him as most of the customers dropped to their knees, covering their heads from the chaos around them. Only a few remained frozen, too shocked to follow orders.

"What do we do?" Uraraka whispered to Izuku. They were near the end of the store, in a place where they were unable action against the criminal. Everyone else in their small group (Ashido, Iida, Yaoyorozu, Kaminari, and Tsu) looked like they wanted to jump in the fight but hesitated. Everyone knew it was against the law and was dangerous.

"We have to do what he says," Izuku said lowly, sinking to the floor. Uraraka followed him down and the others soon copied. "If we do something, we might make him mad enough to shoot someone. We can't get there in time - he's closer to the clerk than-"

"KID! WHAT DO YOU THINK YOU'RE WHISPERING ABOUT?"

That was the moment Izuku realized this was going to be a bad day. A really really really bad day.

"N-nothing," Izuku said. Don't come over here. Please don't come over here.

His silent pleaa didn't work.

Yanking the clerk with him, the villain stormed over to Izuku, stopping short right in front of him. His murderous expression remained, not an ounce of sympathy apparent. "I don't like liars, kid. You got something to say?"

Up close, Izuku could see his eyes were an eerie… yellow. And they were strangely growing cloudy. Cloudy? Is that his quirk or something? "I told you to get on the floor. I told you to be quiet. But you didn't listen to me… they never do." The hand holding the gun to the clerk's head pressed tighter against his skull.

"NO! Don't hurt him!" Izuku shouted. When had things gone so wrong? "Please, just think about what you're doing. You're going to regret this…!"

"Oh, I'll give you something to regret." The villain's gloved fingers twitched in the direction of the gun's switch. Izuku's eyes widened, a gasp spilling from his lips. Something was going to happen if he didn't do anything. That clerk was going to get killed if he just sat there and watched!

What can I do?! If I make a move, I risk everyone's life in here, which isn't an option. But if I don't do anything, I know that man's going to die. I've got to think… how can I turn the situation around? What's the right thing to do?

However, it turned out he didn't have to do anything. The petrified clerk had seemed to lose the ability to think rationally in his terror and was desperate to do anything to save himself. He abruptly kicked his captor's legs and, unbalanced, the villain flew backwards and landed flat on his back. His gun slipped from his grip and clattered to his side.

The clerk was at last released and he bolted away, screeching for help.

Darn it!

Izuku gritted his teeth. The man shouldn't have done that - the villain could've easily shot him if he saw what he was going to do beforehand.

But he hadn't. And Izuku knew what he had to do now.

I need to take advantage of this opening! It's the only one I've got!

Without another second to spare, he leapt forward to try and grab the fallen gun away from the villain's side before he could get his hands on it himself. This was the only way he could help without actually fighting. Every instinct within him screamed that close combat with a gun was a mistake. He should run away while he had the chance.

But his eyes couldn't help but scan over all the terrified people hunched over on the floor. Through tear-filled eyes, they were looking for deliveranceLooking for help. Looking at him.

He had to save them. If the villain got his hands on that gun again, someone could get hurt. He was the only one who had this opportunity… I have to do this!

However, he didn't expect what happened next.

The villain gave a nasty smile, yellow eyes locked on his. Izuku expected him to lunge towards the gun… but he didn't. He simply closed his eyes-

-and exploded into a yellow fog.

Bewildered by the change of events, Izuku could only stand there as the gas expanded towards him and the other people. Everyone started to scream, scrambling away from the potentially poisonous fog. It was no secret how dangerous quirks could wind up being - if this even was his quirk.

Izuku tried to use Full Cowling to speed away, but nothing happened. He desperately tried again, but his quirk just… wouldn't work.

A quirk-canceling gas? his mind screamed as the yellow mist at last enveloped him. Nearby, his friends were panicking, screaming that they were coming to save him, but he couldn't let them. They'd be in the same state he was in right now. He was terrified by what might happen to him but he wasn't going to put his friends in danger, too.

"G-go!" he choked out. The yellow gas tried to squirm its way into his throat as he spoke. "Get out of here… s-save the others! I'll get out of here my-myself!" He leaned over as a coughing fit strangled him.

"...Deku…!"

"Hold on!"

"We're coming!"

"NO! S… stay! I-I'll be fine!" he rasped. "I promise. GO!"

"No, we can't leave him-"

"The back door's right over here-"

"-only got a minute-"

"Midori…"

The fog clogged his ears and he suddenly couldn't hear his friends anymore. He couldn't think. He couldn't breathe. Choking on his own breath, he slowly sank to the floor. For ten slow, pounding seconds, he was certain that he was going to pass out.

His head spun. His body was weak. He felt faint.

He remained on the floor, awake but immobile.

What's happening to me?

Silent minutes passed. By now, the yellow fog had completely enveloped the store. Dimly, Izuku wondered whether his friends had decided to leave, but hoped at least all the customers had made it out.

I can't… keep lying here…, he thought. If I do… I'll die… I have to at least try and escape. He struggled to sit up, gathering his surroundings.

It wasn't likely that anyone would come back after leaving to save him. Nobody knew the gas's qualities and didn't want to risk toxic exposure. It'd be hours before a specialist team would get inside and by that time, he might be dead. I can't be sure someone will be able to save me in time. I have to do this on my own.

He squinted through the yellow haze, coughing. The door's a little over there to my left… if I can just get over there, maybe I can make it out. It'll be easier for someone to be able to help me if they're nearby, too.

Tensing his shaking muscles, he slowly made his way across the floor. Every once in awhile he had to stop and catch his breath. The fog allowed him to breathe, but barely. Oxygen was far too scarce to survive with for long.

Finally, he was able to reach the door. He noticed the fog hadn't tried to escape underneath the bottom of it yet, but didn't have time to ponder over the abnormality. He had to escape or he was going to die.

Izuku pushed open the door, allowing the fresh air to come in and him to get out. His mission complete, he stumbled to the ground, whatever adrenaline he'd had before draining away.

"...meone's coming out!"

"Is it the villain?"

"Oh my gosh, run!"

"No, look-!"

"It's the kid! The kid's alive!"

Izuku wanted to cry in relief as a few customers from earlier ran over to help him. Exhausted, he let them lift him to his feet and help him over to a grassy area in front of the store.

"Kid? Kid? Are you okay?"

He coughed violently, feeling himself go pale. "Yeah… yeah…"

"He doesn't look too good."

"How far away is the ambulance?"

"Call those other hero kids over here! They've been trying to get back in to save this one."

Someone ran off while a man and a woman stayed to support him as he sat on the grass. He felt much better than he had while in that store, but was still light-headed and generally out of it. He knew he would need a while before he'd go back to feeling normal.

"Do you know what that gas was?" the woman asked him worriedly. "Gosh. I hope it wasn't poisonous. You must've breathed a lot in."

His limp head jerked up. "The gas!" He'd left the door open! Was it escaping into the street? Would the others be affected by it?! He had to let them know…!

However, when he managed to focus his blurry eyes on the store, he saw that the fog hadn't moved. In fact… it was shrinking. Through the glass windows, he could see the dense yellow starting to fade away. It hadn't even tried to make its way out like a regular gas.

What the… what's going on?

"DEKU!"

A scream wrenched him from his thoughts. He turned his head towards the source of the cry and saw Uraraka and the others running to him from the back of the store, faces streaked with tears.

"Midoriya, are you alright?" Iida shouted. His group of friends at last reached him and dropped to the ground by his side, everyone reaching forward to touch him like they wanted to make sure he was real. The man and woman who'd been helping him took a step back.

Izuku gave another cough, and then croaked, "Yeah. I was pretty freaked out… but I'm not dead, right? And… I don't feel that bad… Not like I would've thought…"

Uraraka gave a sob. "We thought you had d-died… we thought we l-left you in there and you… y-y-you didn't c-come out… a-a-and…"

"No, d-don't cry! I'm okay, I swear!" Izuku looked her straight in the eye. "I told you guys to go. And it was the best thing you could've done. I'm really proud of you - all of you."

"Thank you, Midoriya… however, I regret leaving your side," Iida said sorrowfully. "You showed great courage trying to retrieve the gun in order to help the others. I wish we had been able to do the same for you. Next time, we will work harder to stop something like this before it even happens."

Izuku smiled weakly. "Let's just hope there isn't a next time."

The next hour flew by in a blur. Paramedics arrived to examine them all, along with some scary-looked people head to toe in what looked like spacesuits. They were there to check out the gas inside and take toxicity levels, though nearly all of the mist was gone by now.

Izuku was taken to the hospital in an ambulance to be further tested in case the gas had any poisonous substances that might affect him. By now, he was feeling much better. The slight dizziness remained, along with a rapidly pounding heart, but he was fine other than that.

"I'm so glad you're okay," Uraraka kept telling him. She came with him inside the ambulance, sitting next to him in quiet support. Only she and Iida could fit in the tiny vehicle, the others having to ride with the police.

"Me too."

When they arrived at the hospital, he was taken away by a team of poisonous gas experts, where they began to test his breath, blood pressure, and pretty much everything else that could be measured. His blood pressure was elevated, but they said that was expected after a scare as great as the one he'd been in. When the breath results came back, they'd know whether or not he'd be okay.

Izuku was nervous, to say the least. He didn't feel like anything was wrong with him, but that didn't necessarily mean he got away unscathed. He really hoped the gas was just a distraction and not a defense mechanism…

"The results just got back," said the woman who'd earlier introduced herself as Dr. Ohno. Izuku and his friends were all waiting in a hospital room, advised not to leave until they knew whether the gas was toxic or not.

"What was the conclusion…?" Iida asked for all of them.

Not poisonous. Please say not poisonous.

"You're going to be just fine," Dr. Ohno at last smiled. A sigh of relief slumped the students in their seats. "The gas was tested for everything from carbon monoxide to phosgene. Nothing showed up. We went a step further to make sure there were no foreign substances in the gas that could be lethal… There was nothing. Since you seem to be showing no symptoms as well, I think it's safe to say the gas was meant for distraction only."

Izuku felt like Uraraka was using her zero gravity on him as the previous weight on his shoulders lifted. He was going to be alright.

"Guess I got off lucky this time," he breathed, while the others cheered.

Dr. Ohno smiled. "You can stay tonight for observation if you'd like, but you're free to go back home if you feel well enough. We're trying to find out if the villain is on any records now to see if anyone has recorded his quirk; we might contact you later to let you know. If you have any questions, call me - I'll be your main doctor for this time period."

"Okay, thanks! I think I'll go back to school. I'm pretty tired, but I don't think I need to stay here." A part of him wanted to make sure everything was really okay, but the thought of staying the night made him grimace. He was a regular patient in hospitals as it was and didn't want to stay longer than he had to.

"Let's get you out of here," Kaminari grinned. "Man, the others are so gonna wish they had come today…!"

"Yeah… Oh, wait! Dr. Ohno!" Izuku had almost forgotten. "When I first breathed in the gas, my quirk wouldn't work. It does now, though." He held up a crackling green hand to prove it. "Do you have any idea why?"

The doctor paused. "Hmm… well, it seemed like an intense situation. The gas was unfamiliar to your lungs, which might've prevented your body from maxing itself out any further. We'll look into it. Thanks for letting me know."

"Sure." He stood up from his seat. "Let's go."

"Wait, wait, wait… Midoriya almost what?!"

Mouths gaped. Class 1-A was all gathered in Heights' Alliance lounge as the students who'd been in the store attack hours earlier explained what had happened

"Holy crap." Kirishima whistled. "If only I'd been there… I could've steeled myself to get that villain before any of it even happened and gotten through the gas."

"I could've exploded it," Bakugo said grudgingly.

"Are you alright, Midoriya?" Todoroki asked.

"Yeah, you seemed to go through a lot for one day."

"As in a lot, a lot."

"Talk about a bad day in town."

Izuku blushed at all the concern. "No, I'm fine! Just glad I'm still alive…" He laughed nervously.

"That calls for a celebration!" Iida declared. "We're all very happy you turned out to be alright. We had been afraid that we'd lost you when the gas overwhelmed the store earlier…" There was a beat of dark silence. "Perhaps we could do something with you that you enjoy to prove our gratefulness for your survival!"

"Oh, no. It's okay. We don't have to-"

"Come on, whatever you'd like!" Kirishima said.

The rest of the class chimed in, saying they'd love to do whatever he wanted. They were that happy that he was alright. Bakugo didn't say anything, but he seemed to agree to go along with the plan.

Izuku grinned, at last giving in. "Okay. I've always liked quirkball, I guess we can do that…"

The rest of the afternoon passed into evening and they all had a great time together playing "quirkball"- an sport where two rivaled teams played soccer… but with quirks. When he was little, Izuku had loved watching the other kids use their amazing powers during the game. It was awesome being able to actually participate for the first time.

Dinner came and went. Before they knew it, it was time to call it a night and get to bed.

"Night, guys!" Uraraka said as she headed into her dorm. "I had a lot of fun today!"

"Same," Kaminari agreed.

"We should do it again sometime."

"Yeah!"

"Maybe tomorrow, we-"

Iida shook his head. "SETTLE DOWN! We can talk about games in the morning. It's been a very long day. I'd suggest we'd all get some sleep now. Especially you, Midoriya, you look exhausted."

Izuku rubbed his eyes. "H-huh? Oh yeah, I guess I am pretty tired… sleep sounds great."

"You deserve it!"

"Night!"

"Goodnight."

"YOU ALL BETTER SHUT YOUR FACES BY THE TIME I'M IN BED, YOU HEAR ME?"

With a slight smile, Izuku entered his dorm. A yawn struck him before he could stop himself. It really had been a long day. Just hours earlier, he'd been dimly laying on the floor, believing death was near.

He clenched his tremoring fists. I'm alive. I'm okay. And the gas wasn't even poisonous. Everything turned out alright in the end. I hope that villain in the store gets caught soon, though… he really freaked me out for some reason.

After slowly getting changed, he climbed into his warm bed. I'll feel better in the morning after a good night's rest. I don't even have class for another day. There's plenty of time to recover and make sure I'm ready for the next time a situation like this happens.

Izuku closed his eyes, waiting for sleep to draw him into its quiet depths. He was so tired - so ready for the peacefulness of unconsciousness…

Ten minutes passed. Nothing. Not even a doze off.

Twenty. Thirty.

Still awake. Alert.

Stupid hyperactive brain. I've just got to relax.

He sucked in a breath, then released, like he did when he tried to loosen himself. His pounding heart remained rapid, but he felt his body lose tension.

Alright, now I'm ready for sleep…

He waited…and waited. And waited even more. Nothing happened.

At the end of his frustration, he sat up in bed. This sucks. I wonder how long I've been up like this… Curious, he grabbed his phone off his desk to check the time.

2:14 AM.

Holy crap. He'd been trying to sleep for four hours and he couldn't even nod off, though he was sagging with fatigue. This was a new level of weird.

He gave up on the hope of getting any sleep tonight. It was obvious that wasn't going to happen. Maybe it was due to all the stressful events of the day, or maybe it was something else… he wasn't sure. This was all so strange.

Well. He might as well get something useful done while he was up.

He slipped down from his bed and padded over to his desk. He could do a little homework while he was up… something to pass the time and be productive. Working might exhaust his brain into falling asleep, too.

All in all, he had a feeling he was in for one long night…