If I wrote the last scene in Endgame.
EXT. UNCLEAR PATCH OF WOODS - DAY
The TIME MACHINE has been rebuilt out in this random bit of wilderness. Bruce, Sam, and Steve stand around the control panel while Bucky makes some final adjustments to the platform.
Bruce flips several switches on his console as Sam LATCHES SHUT a METAL CASE that contains all six INFINITY STONES.
BRUCE
Now remember, you need to return all six stones to the exact moment we got them from, or you’re gonna spin off some nasty alternate realities.
Sam hands Steve the briefcase.
STEVE
I know, don’t worry.
Sam walks with him over to the time machine platform.
SAM
You know if you want, I could come with you.
STEVE
I appreciate it. But I’ve gotta do this one on my own.
Sam nods. He hangs back as Steve comes to a stop next to Bucky. Bucky turns and meets Steve’s gaze.
STEVE
Don’t do anything stupid while I’m gone.
BUCKY
How could I, you’re taking all the stupid with you.
BUCKY
I’m gonna miss you.
STEVE
I’m gonna miss you, too.
He smiles, wistful, then steps onto the platform. Bruce adjusts some dials while Steve thumbs his compass and looks down at the Pym particles…
SAM
How long’s this gonna take?
BRUCE
For us? 5 seconds. For him, as long as he needs. Ready?
Steve nods curtly. He pockets the particles, picks up Mjolnir, and braces himself as Bruce BOOTS UP THE TIME MACHINE…
BRUCE
Going quantum in 3… 2–
Bruce startles. He hits a button on his console, causing the machine to WHIR TO A STOP.
He looks at Bruce, who seems very confused.
SAM
Never mind, I’m sorry. I thought I saw something. False alarm.
Steve is concerned. He tries to catch Sam’s gaze, but Sam looks away… something’s up. He steps off the platform and approaches his friend.
SAM
Yeah. It’s nothing, I just– it doesn’t matter.
STEVE
I feel like it does.
SAM
It really doesn’t, I just– I imagined for a second there that you were gonna go back for her and– I mean, I want you to do whatever you need to do to be happy, but it made me think… after the snap, in the moments between being here and being gone, I realized there was a lot I never said to you.
Sam looks around; this is kind of a weird audience for this. But Bucky gives him a small, encouraging nod.
SAM
I mean, after Afghanistan, I got out, you know. And I made this life for myself that felt normal and right and… fine. But then flash forward 3 years and I’m a fugitive from the law, back in the line of fire and–
STEVE
I never meant to drag you into any of this–
SAM
No, no! I– when I met you, it was like… everything changed. I mean, I just offered to follow you back in time! I don’t think I’ve ever felt that way about anyone else. And I’m not sure what that means, but. I feel it means something.
Bruce’s eyes go wide; he feels like maybe he shouldn’t be here but he also doesn’t want to draw attention to himself by leaving. (Also there’s not really anywhere to go.)
SAM
I just want you to know that… if you do come back, there’s a lot of life waiting for you here.
Steve nods. He swallows hard and turns to look at Bucky, who gives him a firm, knowing nod.
STEVE
I know. I just don’t–
SAM
No, no, you don’t have to say anything, do what you need to do. I just didn’t wanna leave that unsaid.
A beat. Steve’s chest is tight, but he smiles.
Steve wraps Sam in tight hug, then pulls away and heads back towards the time machine.
He stops next to Bucky, puts a hand on his shoulder, then climbs back up onto the platform. He takes a breath, picks up Mjolnir again, and looks to Bruce:
Bruce looks from Sam to Steve to Bucky: seems like that moment is over. Cool cool cool cool cool.
He makes some keystrokes and starts booting the time machine back up.
BRUCE
Going quantum in 3…
Sam TURNS AWAY as the machine revs up. Steve takes one last look at his friends, then exhales slowly and closes his eyes.
The machine WHIRS; there’s a FLASH of BRIGHT LIGHT and–
Steve’s gone. Bruce adjusts some settings:
BRUCE
And bringing him back in 5… 4… 3… 2–
Bruce pulls a lever, but nothing happens.
BRUCE
I don’t know, he blew right by our time stamp.
Bruce makes some frantic keystrokes while Sam watches.
Sam looks like he’s starting to panic. Bruce’s fingers fly across the controls as BUCKY NOTICES SOMETHING in the distance.
Sam looks up and sees it, too: there’s a MAN SITTING ON A BENCH by the lake. (There’s a pristine lake in these woods.)
Bruce steps back from the controls while Bucky and Sam cautiously move towards the man. They watch him for another moment, then:
Sam hesitates, but Bucky gestures for him to go on. He takes a deep breath, then walks over.
At the bench, Sam stops to get a good look: it’s STEVE, BUT HE’S OLD. Very old. Like, suburban-grandpa-who-retired-to-Florida-a-decade-ago old. Sam takes this in.
Steve turns and lights up when he sees his friend.
SAM
So this is your new look, huh?
STEVE
You should see the other guys on my lawn bowling team.
SAM
So you decided to stay?
STEVE
I did. And I– if it were different, I maybe would’ve… but all these years, I feel like I’ve been pointing towards this thing, and I was suddenly so close, it just felt like–
SAM
I understand. I’m happy for you, I really am.
(a beat)
I’m just bummed that I’ll have to live in a world without Captain America.
STEVE
Well. That reminds me…
Steve reveals the CAPTAIN AMERICA SHIELD leaning against the bench. He picks it up and HANDS IT TO SAM.
Sam reluctantly takes the shield. He looks it over, then slides it onto his arm… it’s pretty dope.
SAM
Like it belongs to someone else.
Sam takes a moment to process this.
STEVE
Captain America should be the bravest man I know.
Sam’s overwhelmed. He nods, grateful.
Steve somewhat awkwardly extends his hand for a shake. Sam accepts it… Steve’s wedding band catches his eye. He looks at it for a moment too long.
SAM
(trying to be casual)
You wanna tell me about her?
A small smile as Steve thinks for a moment.
STEVE
I don’t think I do.
PRE-LAP: A grainy recording of some mid-tempo swing standard.
A suburban street lined with all-white houses in an all-white neighborhood. We’re in Westchester, probably. Or maybe Bergen County, New Jersey.
We press in on the whitest house of them all:
A boring little home. In the living room, Steve SLOW-DANCES with PEGGY CARTER. He spins her around and pulls her close. They smile and lock eyes. He pulls her in for a KISS.
We push past these two pieces of white bread to the card table in the corner of the room. Sitting next to the record player is STEVE’S COMPASS. But where there was once was a picture of Peggy, now there’s a NEW PHOTO:
It’s a candid shot of Bucky, Sam, Steve, and Nat, bright wide-eyed smiles all around. Sam looks at Steve, glowing.
Close on the photo as the music swells and–