This is the shortest thing I've ever posted, but I didn't want to draw it out needlessly. Hope you enjoy!
Warning: Spoilers for Endgame ahead. Turn back now if you haven't seen the movie.
May 7th edit: This fic was written and posted to AO3 before Joe Russo's announcement that old!Steve is from a different timeline. At the time of writing, it was assumed that Steve went back and changed his own timeline; the fic remains unedited in this regard. However, I wholeheartedly believe that Steve rescues Bucky in the alternate timeline, and does other wonderful things, such as making sure Howard is a good father to Tony, and keeping Hydra from growing within SHIELD.
"You're not coming back, are you?"
Steve jerked his gaze up from the tablet he was using to review his coordinates, and saw Bucky leaning against doorway, arms crossed over his chest.
Steve's mouth opened, closed, then opened again. In hindsight, he should have known he'd never be able to keep something like that from Bucky for long. "How did you know?"
Bucky rolled his eyes, and shrugged one shoulder. It was a language Steve still understood, even after all the time that had passed.
"Anyone else know?"
"No."
Steve got up from the table he'd been hunched over and walked over to Bucky. "Do you want to come with?" he offered, though, deep down, he already knew the answer.
Sure enough, Bucky just shook his head. "I actually really like it here. Besides, with you gone, someone has to make sure things stay working."
As hard as it was to do so, Steve could only nod. He respected his friend's agency far too much to force him down a path he didn't want.
There was one more thing he needed to take care of before he left, however, and Bucky's last words were the perfect segue to address it. "Speaking of…"
Bucky immediately cut him off. "I don't want it." The former Soldier's expression was neutral but firm. Steve knew from years of experience that there'd be no changing his mind.
"You sure? Because once Sam gets it, I'm pretty sure he won't let you so much as touch it."
Bucky nodded. "I'm sure. Give it to Wilson."
"Okay then." Steve turned back to the table and gathered up his tablet and scratch paper. "Do you want me to look for you?" he asked, not having the courage to turn around and see Bucky's expression.
There was a long silence before Bucky replied. "You can't. Or I might not end up here."
Now, Steve looked over his shoulder, and again saw the resolute expression on Bucky's face. "Are you sure?" he asked, not because he didn't trust Bucky, but because he had read Hydra's files and knew only a fraction of just how much pain and suffering his friend was assuming, in order to keep his own endgame the same.
There was a brief flash of hesitation in Bucky's expression, but he nodded. "As awful as all this can be sometimes, it's mine." He shot Steve a sidelong glance. "And I found it all on my own."
In lieu of a response, Steve just stepped forward and pulled Bucky into a hug. "I'm really going to miss you, Buck," he said, feeling the magnitude of what he was giving up well in his eyes for the first time since making his decision.
"All of us will too," Bucky replied, as he tightened his arms around Steve.
They stood like that for a long while, the air surrounding them filled with things unsaid.
"If you go out there like that, everyone's going to know something is up," Bucky finally spoke up, his voice thick with emotion.
Steve took a deep breath against Bucky's shoulder, then pulled away, and nodded, before straightening his spine, rolling his shoulders back, and smiling lopsidedly. "How do I look?"
"Like a punk."
"Takes one to know one," Steve fired back, a real smile dawning on his face for the first time in a very, very long time.
Unfortunately, the moment was broken by his phone chirping. "They're ready for me," he said, after reading the message.
"Then that's my cue to go." Bucky turned to leave, but was stopped by Steve's hand on his shoulder.
"Take care of them, alright?" his friend implored. "Even Sam, though he'd going to hate it. They need someone to show them what they could be."
Bucky nodded solemnly, and rested his hand on top of Steve's. "Always."