A/N: As promised, a Zombie AU.

Warnings: language, minor violence, mentions of attempted suicide.

Won't Feel A Thing

"What the hell happened?" was the first thing Tony cried out.

He was on his way to the labs for some tools he forgot to take this morning when he heard a single roar and the dull pounding ahead. Instantly quickening his pace, he lunged forward and around the corner of a corridor until he reached the doors to the chemistry lab and saw Barton leaning on it heavily with his back, breathing ragged and eyes wide.

"Fuck if I know!" the man yelled in reply. "I came to check on him, and he was just standing there, shaking, with a gun in his hand, and the next thing I know he's already changing!"

"Fuck!" Tony swore, rubbing his forehead, just as another thud rocked the closed door. He did a quick mental headcount: Rogers and Thornton were out searching for supplies, and Romanoff – in one of the break rooms on this floor, with her leg in a cast. Not perfect. "Can Romanoff move on her own?" he asked Barton.

"Not very quickly," the guy shrugged in reply.

Thud. The door was not going to last.

"Then help her get to the basement. I'll handle him."

Barton nodded and stepped away. Only he didn't actually go anywhere, taking out a sawn-off rifle from the holster on his belt.

"I'll help you."

"Put that thing the fuck down, Barton, I said I'll handle him!" Tony almost hollered in reply.

Another thud, louder one, accompanied by the cracking wood and the champing growl.

"Fuck that!" Clint's voice was thick with anger. "He's too dangerous, and you know it! He's already almost bitten Tasha once, I'm not gonna wait 'til he eats one of us in our sleep!"

That's when the door burst into splinters, and the minutely distraction was enough for Tony to grab the rifle from Barton's hands and push the man down the corridor.

"Get Romanoff to the basement!" he yelled, content that the only response he got was the sound of the footsteps running away. Barton knew the priorities.

And so did Tony. His were standing in front of him right now, among the remains of the door, seething and growling and insatiably hungry.

It was two months since the world ended – a Zombie Apocalypse, as Barton often referred to it, and roughly two weeks since their mismatched group of survivors barricaded themselves away in the Culver University's Natural Sciences Building, united by one Dr. Bruce Banner's inspiring idea: "We should look for a cure." The work didn't go particularly fast though, mostly due to the facts that a lot of the equipment was damaged, and Bruce wasn't even a biologist but a nuclear physicist and, well…

A zombie.

A superhumanly strong, deathly pale (with a greenish tint) and frighteningly single-minded creature that now stood in the ruined doorway, its only thought being "feed" and its only prey being Tony.

"Hey there, big guy," was all Tony's whispered before turning around and rushing away, the fuck away from the thing.

A human can't outrun a zombie. That's a simple fact of life that you either learned early on or died uneducated. But that wasn't Tony's goal – he had just to lure Br- the creature to some safe place. The acoustics lab (that doubled as Bruce's room) was the best choice: it was close, open and had a reinforced door (the reason Bruce picked it as his room in the first place).

Tony didn't look back. He didn't have to – he heard the thing's screeching growls behind him, knew that it smelled his fear and adrenaline and would not drop the chase unless some other, simpler target could be found. The engineer felt its touch, barely there, on his shoulder and doubled his speed, rounding the corner and storming in the lab in a few lightning fast steps.

The place was mostly empty: they had moved all of the equipment to the different rooms, which now proved especially useful for Tony, who has reached the far wall and was turning back to the door, plotting his escape route.

The creature crashed into the metal doorframe in its hurry to get into the lab, but did not let even a grunt out. Instead it growled, low and menacing, the sound boiling up deep in its throat as it slowed down a little on the way to its cornered prey. Its face was a waxy, scowling mask of bared teeth and glazed over eyes, but the thing that scared the engineer the most were the fucking glasses. Pristinely clean, scratched wire-rims with a tiny crack on the left lens. It was not Bruce Banner, and yet still it was.

Tony pushed the thought ruthlessly away, and instead got a better grip on Barton's saw-off. He needed to get out of the lab, which meant getting past Br- the thing, which meant somehow distracting its attention for a couple of seconds – long enough to get around it. There was only one plan of action that immediately came to mind, and no time to think of another, and so Tony shouldered his rifle and let out a single shot in the creature's leg.

"Sorry, buddy," he muttered, dashing to the right, hitting the thing's head with a buttstock for good measure. It howled, with anger more than pain, and wriggled to catch Tony's forearm in an iron grip.

Too close. Too close. Tony had to react now, and so he gripped Barton's rifle with both hands and slammed it in the creature's face, jerking his hand at the same time with all the strength he had left, ripping the fabric of his shirt. He was in the corridor in less than two seconds, and the last thing he saw before clicking the door shut were the shards of Bruce's glasses all over the thing's face.

Tony pressed his back to the door and slid down it slowly, until he was sitting on the floor, head hung low, fingers interlaced on the back of it. He heard the thing rage back in the lab, hurling itself against the door and the walls, grumbling and growling in helpless anguish. Doesn't matter, the door will hold. Now he just had to wait until it tires itself down, and then he can come collect his friend.

Because yeah, Bruce Banner was special, and not only because he put up with Tony's shit (and even seemed to enjoy it) and understood his science babbling, but also in no small part due to him being a bloodthirsty zombie only part time.

The details were hazy, even to Bruce himself. He only told the rest of them what he remembered: him and a couple of his biologist friends, including his fiancé, working in the radiation lab of the University on the Z-Day, then some commotion, a creeper bursting in, Bruce being bitten, then something wrong going off in the Gamma Pulse machine, a searing green light… waking up to find everyone he ever knew dead, and himself infected.

There was a catch though – Bruce's particular case of the virus (most likely altered by the radiation) worked in sort of cycles, dormant most of the time, until released into his systems along with the high enough dose of adrenaline. It made things difficult, to be sure, since it prohibited the man from feeling strong emotions and being under stress in general, which was… well, virtually impossible to achieve with the 90% of the Earth's population dead and another 8% trying to eat you.

Still, he managed. Tony had absolutely no idea how, but Bruce managed, devoted every waking moment to finding the cure, which was not an easy task even with Tony's help, and had a lot of incredibly stressful setbacks and…

"…just standing there, shaking, with a gun in his hand…"

Wait, a gun? The reason Bruce transformed… it couldn't be…

Tony was distracted from his thoughts by a quiet, painful moan coming from behind the metal door. Not hungry, just… hurt. He jumped to his feet instantly, unlocked the door and stepped into the lab, spotting his friend right away in the middle of it, lying face down on the floor, trembling. He quickly picked up a heavy blanked from Bruce's makeshift bed in the corner and put it around the man's shoulders, prompting him gently to sit up.

Bruce flinched reflectively at the touch, excessive sensitivity and confusion of the afterchange mixed with his ever-present fear of unintentionally infecting someone, to which Tony just somewhat tightened his grip on the man's shoulders and whispered in what he hoped was a soothing manner.

"Easy there, buddy. See, a blanket, I'm not touching you."

"Is everyone…" Bruce croaked out, running a hand over his eyes, sweeping away the tiny fractures of glass stuck in his skin. Tony noticed that there was no major damage both to the man's head or his leg, even though it was probably due to the virus' increased healing rather than the weakness of Tony's blows.

"Cool, all's cool," he reassured quietly. "Barton got all trigger-happy for a moment, but it's all good now."

"I… I'm so…"

"Shut it, Banner. The new strain, it didn't work?"

"No."

"And you, uh… Barton said you had a gun… did you want to, uh…"

"Yeah."

So Tony was right then.

"Look, Bruce, it's…"

"Stupid, I know."

"That's not what I was going to say."

"That's how it is," the physicist sighed heavily. He did a couple of deep breaths, in and out, before speaking up again in rushed, but subdued, muffled voice. "I just… it's so hard, you can't even imagine what it's like. The burning, the pain, the… the hunger. But I thought… I can make it worth it, you know, if I found a cure it would all have been worth it, but I can't, I didn't mean, but I p-panicked, Tony, please, you have to understand..." he pleaded, looking anywhere but on his friend.

"I understand," Tony said simply. For a minute or so he just sat there, arms tight around Banner's shoulders, the ghost of the bloodhungry creature in the air between them. Then suddenly he was speaking again. "You know that MRI scanner in the basement?" he asked with an obviously forced light-heartedness. "I got a little deeper into it this morning, and I'm pretty sure I can fix it. You'll have additional data for the research, Rogers and Thornton will bring in more subjects, and we'll crack it the next time. We'll save the world. Save you, buddy."

Banner did not reply for a couple of minutes, and when he did his voice was low and resigned.

"You do realize that even if we…"

"When," Tony corrected decidedly.

"When we find it, all the data suggests that… It's a retro-virus, Tony, the thing that affects them, the c-creepers, it's complicated as all hell, but it can be counteracted, at least theoretically, but I… I'm not like that. I don't even know what I am, but the thing is I don't even care anymore," Bruce said, finally lifting his eyes at Tony, defeat written in them clearly.

"So what, you gonna just give up?" Tony asked, but it came out wrong, harsher than he intended, much more raw and hurt than he ever wanted to let out.

And Bruce reacted to that, of course, jumped up and away from the engineer, discarding the blanket, and for some excruciatingly long seconds simply breathed, loud and slow, simply stared, hard and angry, at the other man. It should have scared Tony, he knew, it should have scared him into leaving (running the fuck away), seeing Bruce struggling for control like that, but all he could actually see was the living, vibrant brown of Bruce's eyes and the bleeding little wounds around them. We'll have to find him some new glasses soon…

Bruce's face was a blank, rigid mask.

"Don't you dare," the man hissed, and then took another quick breath to calm himself. "After the accident, I woke up with my fiancé's flesh stuck between my teeth. I can hear every drop of blood being pumped through your heart, your very smell makes my mouth water. It… burns. I don't want to... be this thing. If- when we find a cure for them, I am not going to…"

"I'll do it," Tony said all of a sudden, surprising them both.

"What?" Bruce screwed his eyes a bit in confusion, and Tony imagined those little wounds turning into little scars.

"If you are right and the cure won't work on you, if there really, absolutely will not be a hope left, you will not have to do it yourself," he said evenly, and immediately realized that he meant it. Hated it, but meant all the same.

It took Bruce some time to absorb Tony's words. "You don't…" he murmured uncertainly after a heavy pause, looking anywhere but on Tony. "I'm okay with that, you know I've already…"

"Don't," the engineer cut him off with a grimace. "If, and only if there is no other way… I'll make it quick, not like your..." he gestured vaguely in the direction of Bruce's arms, and the physicist hurried to hide the rough scars self-consciously behind his back. "Near the temple, you won't even feel a thing."

Another pregnant pause settled over them, filled with nothing but breathing and wondering when it all went so horribly wrong. Tony thought that it was probably an another life when he finally looked at Bruce again and saw a faint, wistful smile form on his lips and heard his quiet, barely audible murmur.

"That would be nice."

A/N: don't think it really needs any background this time.

I really hope it wasn't actively horrible, so, please, leave a comment if you have time.

Next time in Kaleidoscope: High School!