It had taken the team years to get back together, and when they did, one James Buchanan Barnes was an ever-present shadow behind the man who had fought for him, stood for him, and killed for him. It was a road to recovery that was going to be long, going to be grueling, but Tony was willing to help.

Tony had already helped.

Did Cap just think that T'Challa had built a new arm for Barnes within a handful of months, with no prior experience in the prosthetics field?

Well, not that Tony really had any experience, but, y'know, suits were close enough, right?

Right.

And really, did Cap think that the Accords just magically rewrote themselves? Of course he did—how could he ever think that Tony of all people had thrown himself into countless hours, days, weeks, months of research and legal battles, all for the sake of the team who had betrayed him and everything else they stood for?

Not that Tony was bitter or anything, really.

Well, maybe a little, especially in the beginning. But he felt guilty, as well. The Accords, the whole mess with Barnes and his parents and his anger? It really could have gone better.

And so Tony did what he did best. He fixed things.

And to see the look on Cap's face when he found out he had Tony to thank, of all people, for fixing it all—

Worth it.

Worth every cent.

It took them a while to fall back into rhythm, to fall back into trusting each other again, working together again, all of them, as Earth gained more and more enemies that needed to be met with more and more force.

They clashed, of course they did, but… it was better. They understood each other more. Respected each other, even.

And then they clashed once again—but in an entirely different way.

This time it was James who instigated it. James who had become Bucky to nearly everyone, James who had started following Tony around nearly as much as he followed Steve around, James who liked to tinker and design and fix, much to Tony's delight.

It was James who instigated it, pushing Tony against a wall, lips and tongue and teeth at Tony's mouth, Steve's eyes startled over Bucky's shoulder, his hand still gripped tight within Bucky's metal fist from when he'd dragged the blond along with him, straight across the workshop and into Tony's space.

Bucky growled and nipped lightly along Tony's jaw as he pulled away, and then looked back at Steve. Looked back at the man who Tony could tell was shocked, intrigued, and… aroused.

Well, he could work with that.

And he did. They did.

They had their share of disagreements over the years, but it was nothing like what it used to be, between him and Steve. They'd been more once upon a time, much like they were now, but they'd also been… less.

Bucky was the thing that held them together, tying the past to the future with his grounding realism and his expert handling skills.

He grumbled many a time that the two of them, the Captain and Iron Man, could destroy the world with their stubbornness—ignoring the flinches at the reminder that they nearly did do that. That they would put him into an early grave with the amount of times that he'd had to chase them around, track them down, force them to sleep and eat and breathe.

But he loved it. He lived for it.

And they loved him, too.

The thing was, that as much as Bucky constantly grumbled about being put into an early grave, Tony was the one most aware of their mortality.

Or rather, his mortality.

Christ, he wasn't even sure the other men were ageing. Well, he knew that they were, but sometimes it just didn't feel like it. He felt every second of his sixty years, hair more silver than ever before, and yet they hardly looked over forty. He knew they were older, but the serum… well, enough said.

And every time he tried to bring it up… every time he tried to tell them that they didn't need to hang around an old man like him anymore, no matter if he was still fit enough to climb into his suit every battle… every time he tried to tell them they should move on, that it would be less heartbreaking for them all if they put distance between them now…

Well, they just ignored him.

And he loved it. He loved the gruff tones they would take with him, the way they would kiss him in the wake of his confessing his fears, the way they would hold him and take him and love him.

It assuaged his fears… at least for a little bit.

He thought he would be the first to go.

Showed how much he knew.

They said it was cell-degradation at a total system level.

Pervasive.

All at once.

His cells had just… run out of steam, supercharged by the serum as they were, and no one had known until he dropped. The cells had been perfect… until they weren't.

He wasn't even in the field—he wasn't even with his husbands, his family, his friends. He'd been giving a lecture to a new batch of recruits, and they hadn't known until… until…

They hadn't known until it happened.

But the moment he dropped, it was too late. There was nothing that could be done, and he died moments later, surrounded by the frantic and fearful faces of young heroes, unsure what to do when faced with something so… mortal.

Not like they could have helped.

No one could have.

But Tony tried.

He threw himself into research the moment he got back from the funeral.

He needed to fix things, to fix James, before it got him as well.

Because he knew it would.

Fate always came for what and whom he loved.

Always.

But fate didn't take away James.

Or rather, it did, but it was by Tony being… Tony. He became self-destructive, refusing to eat or sleep hardly at all, only enough to keep himself going, trying desperately to save his husband. His last husband. The one who loved him, and whom he loved, but was letting down with every experiment that failed.

The months passed, but he came no closer. He was failing.

He was failing.

He was Tony fucking Stark and he couldn't fail—he couldn't possibly—

But he did.

He had failed Steve, and he was failing James.

"I'm leaving."

Those two words struck him to the core, snapping him out of his fugue, his restless half-awake dreams—his nightmares—in the middle of the night.

Bucky had pulled him from his workshop late last night, insisting he get to hold onto his husband because he hadn't done so in a week. In longer, truly.

Now he knew why.

Tony rolled over, bones creaking, pain shooting down his spine, and stared, shocked, into Bucky's eyes. "What? No, you can't leave! Bucky, please, what did I do, why are you saying this?" he pleaded, hands quivering between them, heart absolutely breaking. "I know it's not the same as with… with him, but I love you, I love you so much. Please don't leave me. I couldn't bear it."

And James gripped both of Tony's hands between his, thumbs rubbing soothingly over knuckles, and ducked his head to press his lips against Tony's cheek. "I know. I love you too, doll," he rasped, tears trickling down his cheeks. "That's why I gotta leave, Tony. I love you too much to subject you to… to…"

He couldn't say it—neither of them could—but Tony knew exactly what he meant.

He knew, in a moment of intense clarity, everything else vanishing from his mind, that if he were in Bucky's position… he would go off to die alone as well. He wouldn't subject anyone else to waiting for him to die, watching, waiting. He would go out, guns blazing, or not at all.

And so Tony wept, clutching at James' shoulders, and knew—knew—that he wouldn't be able to change the man's mind.

Plus, well, Tony knew that Bucky missed Steve. They both did, but they… they'd had something special. They each had, but their special was… it was age-defying.

He couldn't stand in the way of that.

He understood wanting to be with Steve again.

Oh, did he ever.

He was gone in the morning, without a goodbye.

Tony understood that, too.

The little reminders were the worst. The clothes, the cologne, the boxing gloves, the mugs that bore their names in italicized script.

Tony always thought he'd be the first to go, not the last.

But, well…

In the end, they didn't have much of a head start.

It was barely a year after Steve that James was lowered into the ground, leaving a trail of blood in his wake.

Barely another before Tony followed them, ready to fight whatever stood in the way of him and his boys, his men, his husbands.

Tony always said he'd face anything for them.

And he did.

He did.

Note: I'm so sorry. I really am. I just had to get this plot bunny out of my head, because it was driving me nuts. So of course I subject all of you to the tragedy as well. For infinitely happier Stuckony, feel free to check out my fic Hanging From a Cross of Iron, which will be updating with chapter two tomorrow! Thanks so much for reading, everyone, and feel welcome to come say to me on Tumblr (Juuls)! xoxo