ENDGAME SPOILER WARNING.

(A/N: It took a second viewing of Endgame before I could even start to get my thoughts down, and this is one of the two stories I felt I needed to write. Bucky definitely knew what Steve was going to do at the end before it happened; at first I thought he'd just figured it out, but now I think they probably talked about it first too. Steve wouldn't just leave Bucky without a goodbye. So this is my take on that conversation and the farewell between two very old friends.)

"I know what you're going to do."

Steve didn't look up; the sudden voice didn't even make him miss a beat as he ate the last mouthful of his burger. Happy had disappeared about an hour ago and returned with enough burgers to feed a small army, which was more or less what they were, but he'd been visibly trying not to cry as he gave Morgan first pick and Steve was very determinedly not thinking about why.

He'd taken his down to eat on the jetty, sitting on the wood with his legs dangling over the water. There wasn't comfort in it, exactly, but there was something peaceful about the still lake as the evening shadows grew long, and he could see what Tony had found here. Family. Home.

The idea had been growing for some time now and it was no surprise to him at all to have Bucky arrive now, even if he hadn't heard him coming.

That didn't mean he was going to make it easy on him, though.

"And what's that?" he asked mildly, balling up his burger wrapper.

"Steve." It was all Bucky said, but it was enough. There was such a weight to it, grief and that weight of lost years that they both shared, and something else - something that made Steve look away from the water, twist up to see Bucky's face.

Resignation.

They both knew where this was going.

Steve let out a long breath, and looked back to the lake. "Sit with me, Buck."

It took a moment. Steve knew it would, and he had time. He had nowhere else to be. This, right now, was for them.

Eventually Bucky sank down beside Steve. He shuffled forward and let his legs hang over the ledge too.

It was on Steve to speak, he knew, but for a while he just didn't. They sat together, side by side, looking out across the water. It rippled now and then with the breeze, and the reflections of the trees and clouds were starting to be touched by the gold of the late evening sun. Little by little he felt the tension drain out of Bucky, his rigidity relaxing into something else, something of more acceptance than pain.

"It's a hell of a chance, you know," Steve said quietly. "The power to travel time and space."

"There's a lot that could be done with that kind of power," Bucky said. He was mimicking Steve, still studying the water while they spoke. "Anyone else would have a million things they'd think of changing. But not you."

Now Bucky did look over, and Steve could help looking his way even though he already knew what he'd see - that familiar crooked half-smile, so wry and knowing. Bucky had always known who he was, and accepted him for it every second of the way.

"It's only ever been one thing, for you."

"That's not quite true," Steve said softly. "If it was how time travel worked, if changing the past could change the future, Buck-"

"I know," Bucky said, laying a hand on Steve's arm. It was his mechanical hand, only the most visible mark of what had happened to him. "It's alright, Steve."

"It's not. None of it is."

"It's not what we ever thought it would be, but it's alright. I was used as a weapon, and if I could undo it so that the lives I took are given back I would - but I'm here now. I'm alive, and I'm me again, and I'm here with you. Right now that's enough, and you did that."

It would never be enough, not when he could almost imagine the life Bucky should have had - a life untainted by HYDRA, one of honourable service and a peacetime job, a family of his own. But he knew what Bucky meant, all the same. They'd lived to see a new century, almost a new world, together, despite everything. It was more than Steve had thought he'd get.

"Is it wrong?" Steve said, his voice cracking. "To go back. To... stay."

It was the first time he'd said it aloud, voiced the idea that had coiled itself inside his heart as soon as Bruce had started to build the new quantum machine. There was no surprise in Bucky's eyes.

"Wrong for who?" Bucky said. He was frowning, but his eyes were still so fond. "You don't always have to be Captain America, Steve. You already saved the world. More than once. You've earned a bit of peace."

Hearing those words was like having a weight lifted from him, or the first touch of morning sun. "God, I hope that's true." He hesitated, then went for it. "Come with me."

"Steve..."

"A new start for both of us. Somewhere quiet. We'll retire somewhere, me and Peggy, and you can come with us."

Bucky snorted. "You expect me to believe you could get Peggy Carter to retire?"

"I'm serious, Buck."

"Ah, Steve." Bucky tightened his grip on Steve's arm. "I know you are. And you know what I'm gonna say."

"Yeah." Steve smiled at him, but it was a weary sort of smile. "I know."

"You can go back. She's waiting for you - you've kept her waiting far too long. But me? I can't go back. There ain't nothing good for me by looking behind. Whatever's next for me, I'm going to find it here."

Steve wondered how it was possible for his heart to feel so full and so empty at once. "I wish there was a way. I really do. I mourned you so long, and I fought so hard to get you back."

"And you did. And I'm grateful for that, Steve, I really am. But it's no reason to put your life on hold forever. You've got a chance to take back the life you should've had, and if you're honest with us both I think you know it's the only one you'll ever be happy in. Be selfish for once in your life, would you? Stop worrying about the rest of the damn world and do what will make you happy."

There were tears in Steve's eyes, and when he blinked them away it was only to see that Bucky's eyes were shining too. God, did Bucky even know how good he was? He'd been through all the crap in the world and this was what had emerged, this man who was the greatest friend Steve would ever know, the purest damn heart he'd ever met.

"What about you, though?" he said, aching right down to his soul. "What will you do?"

"I reckon I've a fair guess what you're going to do with that shield, eventually," Bucky said, and there it was again, that little smirk that had seen far too much of Steve's crap to be surprised by anything. "I reckon I'll stick around to give him a hand. He's a pain in my ass, so I guess he's a perfect replacement for you."

It actually startled a laugh out of Steve - a true laugh, momentarily unburdened, the kind only a precious few people had ever drawn from him.

"You're a dick, you know that?"

"I learned from the best," Bucky said pointedly. "You gonna tell Wilson what you're doing?"

Steve had already considered this. "Nah. I'll surprise him."

"Man, he's gonna love that."

Steve shuffled sideways, closing the last of the distance between them, and put his arm around Bucky's shoulders. For a moment he shut his eyes and just was - he listened to the wind, to the distant voices back up at the house, and felt the reassuring presence of his best friend, memorised what it was to have this steady, unyielding comfort at his side.

When he opened them again the world was unchanged, except that the sun had inched a little lower in the sky.

"I'm really going to miss you, Bucky."

"Yeah." Bucky's voice was thick and shaky. "You too, punk."

"'Til the end of the line."

"Way beyond that, Steve. Wherever you go, whatever happens. I'm with you."

"I know." He knew it sure as his own heartbeat.

"Tell Peggy I said hello, won't you?"

Steve was going to miss Bucky for the rest of his life, that much he knew. It would be a different kind of grief, but grief all the same - because he might never see Bucky again, and he'd be an old man even if he did. They were both alive, but theirs would be lives always lived apart. And it was Steve's choice this time, and he almost second guessed it because it struck at something so deep within him to separate himself from his old friend.

But Bucky was happy here. He'd find his way without Steve, be something so brilliant that Steve hoped he lived long enough to see it. And Bucky understood, because he'd always got Steve so well.

Steve could do well here, but he would never be truly happy. He'd found the place he was meant to be decades ago, and the chance to go back to her wasn't one he could pass up.

"Yeah, I will."

"When are you going?"

"Bruce said it'll be ready tomorrow. He's working on it now - I think he couldn't stand to... the funeral, it was too much for him."

It had been too much for Steve, too. How he could ever have thought Tony would refuse to lay down on the wire, to make the sacrificial play - and here they were now, with Tony dying to take Thanos down, to save the entire universe. There was regret there that would stay with Steve forever, regret and pain and the loss of what had been and would could have been, and he didn't think he'd ever be free of it. But with the world saved, he thought, really, that Tony would have understood - might even have been happy for the choice Steve was making.

"Tomorrow," Bucky echoed. For a moment he surveyed the water and his face looked far too old and burdened, grieving for what was to come. But when he looked back to Steve he was a young man dragging Steve out to the Stark expo, or showing up at the doorstep with dinner or coercing Steve into a game of cards; he was full of life and determination and stubbornness, just as he ought to be. "One more night then, Steve. If you want to sit here a while longer."

Steve took him in, his best friend lit by the brilliance of the setting sun, loyal right to the end. "Tonight, Buck, there's nowhere I'd rather be."

He'd be back with Peggy again tomorrow. They'd get their dance, so very long overdue, and Steve would try to live a life of peace and honour his friends. It was what he wanted, what he needed, but he was leaving people he loved behind here, too.

But it was alright, in its own way. They would miss each other, Steve could already feel how much that was going to hurt, but it was alright. They would both be where they were meant to be; James Buchanan Barnes would still be at Captain America's side.

And if it was only the two of them who would remember how it was right in the old days, when it was just Steve and Bucky against the world, ready to fight before they even knew what the fight was - well, that was how it should be.

For one more time, Steve and Bucky sat side by side and watched the stars come out.