At first, it was funny.
These days he's both disturbed and ashamed they'd ever found humor in it, but that was the truth. He supposed they'd grown used to the reversibility of things; they were the Avengers. In the golden days, the decade and a half after their founding, there wasn't anything they couldn't undo, any foe they couldn't best. At the end of the day they took plenty of damage, but it was bruises and broken bones and fixable things.
So when they first heard about the zombies, it was kind of funny.
Part of it was that they underestimated the transmissibility of the disease. They were all so used to supervillains, with their grand plans and even grander failures, that they assumed Loki had decided to use the undead as his minions this time around, "magicking" people up from their graves to roam.
But it wasn't Loki, and it wasn't magic.
It wasn't a supervillain, wasn't even a criminal; it was an idiot college student messing with things he never should have messed with. Rumor was he'd been trying to solve the common cold, but he was long infected by the time SHIELD tracked him down, and there was no way to find out if it was the truth. It hardly mattered anymore anyway.
Because magic was reversible, fixable, in a way that the virus wasn't.
It was a fluid-born pathogen, transferrable through liquid, mostly commonly through getting bitten. Within ten to fifteen minutes, you died. Within three to five minutes of that, you rose. They maintained no memories, no personality, no intelligence; they were killing machines, nothing more or less. It wasn't brains they were after, but blood, and they were unrelenting in their hunt for it. They didn't need to sleep or make waste, didn't even need to breathe. In terms of weaknesses, they were sensitive to temperature, particularly the cold, and couldn't swim worth a damn, but other than that they were unstoppable by anything but direct, irreparable damage to their brain.
Walkers, they called them-Clint had made a joke once in the beginning, a reference to some show he had never gotten around to watching, and it stuck because zombies were something that happened in cheesy movies and hokey books, not a terrifying disease sweeping the world faster than they could hope to keep up with.
There was no cure, not yet. At first, the Avengers had been right on the front lines, working with SHIELD to do everything they could. They spent every possible moment of their day taking out walkers, because even after the brief, morbid humor of it passed, there was still hope. For maybe two weeks, it looked to be containable. Walkers were easy enough to kill, and they were slow, trudging beings, senses so dead that they could only spot a human if they were less than five feet away
Week three was when things got apocalyptic, because week three was when the virus mutated. Walkers suddenly developed into fast, vicious creatures that could sniff out a human from two football fields away, and the days and weeks and months after that were a blur of blood and gore and a steady loss of hope.
The Avengers kept safehouse in the Tower; they were about as safe there as safe got. The top floor of the Tower was reachable only by elevator, to which Tony had cut the power lines. The Avengers came and went via Thor, Hulk, or Iron Man, and, back when the world was moderately functioning, by helicopter or plane.
As far as loved ones went, things were bleak. Bucky and Phil already lived with them, and Bruce, Natasha and Clint only had the Avengers. Thor and Tony were the only ones with friends on the outside, but they were both too late. Rhodey and Pepper were gone before Tony could get to them, a loss that Tony still mourned on quiet nights when the reality of their world cut a little too close to the bone.
Even in the apocalyptic blur that became their lives, there were certain markers Steve couldn't forget.
One month, one week, five days, and Steve was bitten. It was Bruce that reminded them of the serum's potential to counteract the virus, and it was Tony who refused to let anyone so much as twitch a trigger finger in Steve's direction until they knew for sure. He was discovered to be immune; he naively considered this a blessing.
One month, two weeks, two days, and Maria was the first person he knew that he saw become infected. It was Phil who shot her point blank. Over their rations later, he told them that was the way she'd have wanted it, to be taken out before she could infect anyone else, and they all came to the solemn agreement that it was the way any of them would want it. They couldn't afford hesitation.
Two months, one week, four days, and it became an inescapable fact that there were more walkers than humans.
Two months, three weeks, three days, and Nick, Phil, and Bucky took one of SHIELD's few remaining planes to investigate a stronghold that was rumored to have an antidote. They didn't return.
Three months, two weeks, one day, and Thor was not as immune as they had foolishly, senselessly assumed. Thor, wanting a warrior's death, struck himself down with lightning; Clint and Natasha both fired a round into his head, too cautious not to. They'd made enough careless assumptions for one lifetime.
Three months, three weeks, six days, and Bruce dropped a vial of walker blood, cutting himself in the process. It was only he and Tony in the lab, and it was Tony who'd had to shoot him in the dead period between infection and resurrection, when the Hulk couldn't interfere. It was the right thing to do, but there were nights Tony's hands still shook.
Five months, one week, four days, and Natasha was next, hand-to-hand skill set proving to be a weakness in this bleak new world. An arrow lodged itself between her eyes in under three seconds. Clint turned to them, eyes flat and dull, and told them simply, "She made me promise." He didn't speak to anyone in the weeks after, and it turned out to be the last thing he said to any of them.
Six months, one week, four days, and Clint went on a suicide mission from which he never returned. The remaining Avengers spent five days wading through bodies for him, and they tried to tell themselves it was because they hoped he was alive and not because they needed to be sure he was dead. When they eventually found him, he had a gun in his hand and a bullet in his brain.
Nine months, two weeks, five days, and it's just him and Tony left.
There are surely more humans out there-it hurts too much to think that there isn't-but it's just them in the Tower, just them in possibly all of New York, and it's the quiet that gets to Steve. He plays music he hates as loud as he can and he turns on the tv just to hear the static and he wants to argue with Tony just to hear his own voice, but neither of them have the heart to anymore.
They got all their fighting out so, so long ago.
Steve still remembers the way they were at first, all snarled insults and heated glares. He remembers the hard lines of Tony's smirk when he said fuck you and Tony asked if Steve was a man of his word.
I-in your dreams, he'd stuttered just briefly, but Tony had known, of course, a sixth sense for Steve's every misstep.
I would have you, right here on this desk, until you begged for mercy twice.
It was a reference to something, something Steve wouldn't learn about for another year, when he would stumble upon it with Thor by accident and have an extremely inappropriate reaction that he'd had to seek Tony out to remedy. At the time, he'd just fixed Tony with a glare.
I don't beg, Stark.
Twice, Tony had merely drawled, amusement and lust sparking hot in his eyes.
Steve hadn't replied for a long moment, then he'd slammed Tony up against the table in a dizzying kiss, and that had been that. It was the first time they fucked, high on aggressive enthusiasm and unresolved tension. They fucked for months after that, each steadily beginning to care for the other and each entirely unwilling to say a word about it. It was Steve who gave in eventually, if only because he knew Tony never would. It was a situation he'd been forced into countless times over the years, but Steve had known Tony was a stubborn ass from the moment they met, he'd known what he was getting into, and he'd never regretted it for a moment.
"For fuck's sake," Steve muttered.
They'd been standing next to each other with a sense of building challenge for over an hour. They'd both declined numerous offers to dance from others, both continuing to stand there as if by moving they would lose some imagined competition.
"I'm sorry, what was that?" Tony raised an amused eyebrow.
He swore occasionally, especially during their…sessions, but Tony never failed to find it amusing.
"I said for fuck's sake, Tony," Steve turned, offering an arm insistently, "Dance with me."
"Took you long enough," Tony took his arm without hesitation, dragging Steve onto the dance floor before Steve's brain had time to catch up with what was happening.
"I've been standing next to you for ages, Capsicle," Tony shot him a grin as they waded through the crowd, "Take a hint already, would ya?"
"You could have asked me, you know!" Steve insisted.
"You'd think I was screwing with you."
It was a fair point; he probably would have.
"You are screwing with me," Steve felt the need to point out.
"That part's good too," Tony gave a little half-shrug, not pretending to not know what Steve was talking about, "But who says I can't want more?"
He wasn't looking at Steve but at the floor, and Steve caught him biting at his lower lip before someone blocked his view. Tony meant it. He let that thought roll around in his head a bit as they reached the center of the floor. Tony turned in his arms, beginning to lead, and Steve followed along amenably. The song ended after a few beats, shifting to something much slower, and Steve didn't hesitate to pull Tony closer.
"So are you going to ask me out, or is that going to take another three months?" They were chest to chest, and though it was unquestionably a demand, Tony's words were hushed enough Steve doubted anyone else overheard. Regardless, he felt himself flush.
"I was working up my nerve!"
"No need to be nervous, Romeo. Come on, they're playing our song, it's all romantic and shit."
"We...we have a song?"
"We do now, don't we?"
Tony flashed him a smile, a real one, and Steve couldn't help but feel a little bit dazzled as he smiled back.
"I guess we do."
The date was a disaster, of course. They fought for an hour over directions to a place supposedly ten minutes away, Tony nearly got arrested for speeding twice on the way there, and spent the rest of the ride complaining about Steve's "grandma" driving. When they finally made it there they were way too late, and their reservations had been given away. Steve suggested a diner he liked instead, and Tony spent the entire car ride threatening to sue mapquest for the shitty directions, the cops for making them late, the maître d' for giving away their reservation, et cetera et cetera. Steve finally told him if he hated it so much they could go home and try again some other night, but Tony just looked at him like he'd lost his mind.
"How could I hate it if I'm going with you?"
Their first date was a pretty good symbol of their relationship. They argued and bickered and pushed each other, but they did it together and they loved each other through it all.
"You're drowning again."
It's Tony's voice, here and now, and Steve shakes his head to clear his thoughts.
"Oh, baby," Tony murmurs, crossing the room to settle in Steve's lap on the couch. He runs a hand through Steve's hair, dropping it to cradle Steve's cheek as he presses a kiss to his forehead.
He always knew when Steve was caught in the trap of reflecting on the past, and he'd been doing it more and more often these days. He loves Tony more than life itself, and as long as Tony is alive Steve has a reason to live, but he finds himself getting caught up in wondering what the point of the future was. It stretched out before him, so wide and endless, yet so utterly pointless.
He knows, they both know, that there's no coming back from this.
If humanity survived at all, it would be centuries before things returned to even a semblance of the world they'd known. Days like today, he just feels so…detached. As if he's somehow been frozen again and woken up here, in this dystrophic wasteland.
Tony stretches out next to him, bumping his knee lightly against the coffee table in the process.
"Tony, you're doing it wrong," Steve rolled his eyes, "You shouldn't have thrown out the instructions."
"I'm an engineer!" Tony huffed, greatly offended, "I don't need instructions!"
"Just let me help, would you?"
"Steve, you can barely work a microwave, I'm pretty sure you don't know how to put together a coffee table."
"Steve. Steve?" Tony's rubbing a thumb over his cheek, sympathy in his weathered eyes, "Steve, please baby, I need you here, okay?"
"I'm here," he takes Tony's hand from his cheek, pressing a kiss to his fingers, the golden wedding band cold against his lips, "I'm here, I promise. I'm just…"
It was hard to stay in the present when the past was infinitely more appealing.
"I know, baby," Tony sighs with a watery smile and tired eyes, "I know."
Tony is plenty reminiscent himself, but it's Steve who is losing himself to it, tripping over and drowning himself in memories every time he turned a corner now. He wants it so desperately, more so even than those first horrible days out of the ice. That had been…repairable. He'd woken up in the future and it was new and different and strange but it was learnable, and above all, it was human. It was life. For fifteen years, it had been his life. He'd found himself enveloped in a close-knit family, a place where he belonged and was loved. He'd had a job where he could do real good, where he could put his life on the line for something that mattered. He'd been reunited with his best friend, alive and well after all those years. He'd married the man he loved.
"Baby, you know I'm scatter-brained sometimes-"
"I left it at the foot of our bed, how in the hell could you not see it, and why-"
"I was in a rush-"
"-on earth would you think the Iron Man suit is a suitable replacement?"
"It totally counts as a suit!"
"I know for a fact you have a million other, much more suitable suits!"
"They didn't look as good, I didn't want-"
"You're the billionaire, go buy a better one then! You don't wear a mechanical suit of armor to your wedding, Tony, Jesus!"
"To be fair, you're a billionaire now too y'know, you could have bought me one-"
"I did buy you one, I bought you the one at the foot of our bed, which you of course completely ignored-"
"Baby, c'mon, you're marrying me and you didn't think to buy a backup suit?"
"Anthony Edward Stark, I swear to God, I am about ten seconds from punching you in the face-"
"I've still got to get you down that aisle without an alien invasion before you can claim that one-"
"And if there's an alien invasion, I am one hundred percent prepared."
"You are one hundred percent an idiot."
"You're lucky I love you, or I might have been offended."
"You're lucky I love you, or I might have punched you already."
Then, the memory is gone and Tony is kissing him. There's no heat there, just a tender pleading to it that has Steve feeling impossibly guilty. He's still alive, he reminds himself. More importantly, Tony's still alive, and Tony needs him to keep it together.
He's rougher that night, overcompensating for his lack of presence earlier. Not too rough, he could never do that to Tony, but rough enough to leave bruises and scratches and aches, enough to leave them both with the lingering feeling of being alive for another day.
When they finish and Tony's breathing evens out, Steve cradles him against his chest and traces his fingers around the arc reactor.
"Tony? What are you doing sitting in the dark?"
Steve walked into the pitch black living room, the only light being a soft blue circle in the middle of the room. He flicked on the lights, and the living room burst into life with a collective shout of 'surprise!', but Tony looked put out.
"Wha…how could you see me?" he demanded, "It was supposed to be a surprise!"
"Tony, sweetheart," Steve tried his best not laugh, "Did you forget that you glow in the dark?"
He had to admit, it kept him up, at first. The light is soft but persistent, never flickering or wavering-which was good, because if Tony's lifesource had a habit of flickering, Steve wasn't sure his heart could take that kind of stress-but at this point he's spent over a decade sleeping next to the light, and could no longer find it anything but soothing.
Nine months, three weeks, five days, and Steve fails at the one job he has left.
They're out scavenging for food between fighting off attacks, and the internal power for Tony's suit finally fails. They had stupidly split up, and Steve isn't there to protect Tony when it happens, doesn't even find out until he's eight minutes too late. Tony is alive, encased inside the suit, but the walkers managed to rip off one of his gauntlets, and Tony's hand is a bloody, infected mess.
Steve shoots every last walker with a vicious enthusiasm he hasn't had in what feels like years.
When they're safe for the moment, he helps Tony get the rest of the suit off. Without power it's just dead weight, and they don't pretend he needs the protection. They don't talk; not about the infection, not about how Tony had to know full well he was going to run out of power, not about how they both ran out of power too long ago.
Steve strips him of the suit and Tony hasn't died yet, but there's no question he's infected. His eyes have dilated and his skin is clammy, and Steve kisses him desperately because he can't not. He's known for a long time they were nearing the end, they both have, but there's still that last flare of impulse to live another day because if he has Tony, even if he has nothing else, it's worth it.
But he doesn't have Tony, not anymore.
Tony surrenders to him, and they kiss for a long moment before Tony's hands are pushing something into his chest. It's cold and hard and metal and Steve knows exactly what it is and what it's for, no matter how much he doesn't want to. They still don't say anything, and they still don't need to. They know that they love each other, and they know that this is their last kiss.
It's soft and tender and forgiving, and then Steve's fingers are catching on the gun in his lap.
Steve's an excellent shot, always has been, even back when they could afford to spare lives. He could hit a moving target while sliding on a zipline when he was just twenty-two, and there is no possible way he's going to need more than a single shot.
He closes his eyes.
He doesn't open them again, and he doesn't need to. He doesn't need, doesn't want to see how Tony's body looks without him in it. He doesn't dwell on what he's done, doesn't let himself think that word, just presses the muzzle of the gun against the roof of his mouth. He wants his last thought to be worth something, so he gives it to Tony as he fires the second shot.
Nine months, three weeks, five days, and everything is quiet.