[Fight scene on a moving train]

America has been trying to remember the first time they did is for a while now, but her brain refuses to indulge her, offering a mess of conflicting memories and jumbled timelines. She spins on her left hill and drop kicks an Hydra agent through the open door and out of an inter-dimensional portal. She can hear Eli whooping somewhere behind her, then a string of swears in a variety of languages that is unmistakably David's. 

America jumps out of the door next, but the portal's already closed. She lands on the next wagon in a hunched position and jumps to her feet just in time to see Kate firing an arrow into another Hydra agent's thigh. Kate proceeds to push him into the wagon's bathroom and then locks the door from the outside. She turns to America with a dashing grin on her lips, her smudged make up and bloody mouth unable to dampen the smug glint of her smile nor the pride shining on her dark blue eyes. 

"¿Te acuerdas...? Do you remember the first time we had a fight on a train?" America asks, stepping over unconscious goons on bright yellow and green suits to reach Kate's side. Kate frowns for a second, then smirks. 

"Do you remember the first time we banged on a plane?"

America lets out a barking laughter just as the door on the opposite end of the wagon bursts open and a dozen more bad guys come flooding through. Kate's got an arrow ready to fire in a second and, a fraction of a moment later, America feels her hands heating up with energy. 

"You don't remember!" she accuses teasingly even as she takes a jump and lowers her supercharged fist on the top of a goon's helmet. Kate's bright laughter is enough of an answer, but it's quickly replaced by mocking quips and a string of jokes in Kate's delightful posh accent. Even after a decade and a half away from Uptown NYC and years without setting a heeled foot on the Big Apple, Kate's sarcastic remarks have an unmistakable high class pronunciation to them, just like America has (gratefully) never lost the strong roll of her r's despite a life away from home. 

She hears a warning 'coming!' through her com and ducks just in time for Teddy to rip open the wagon's ceiling and fly down in a whirlwind, knocking down all of the Hydra agents with a swoop of his wings. Tommy zips down through the open hole, leaping at super-human speeds and disarming the bag guys before they can get back to their feet. A tingling of magic runs through the wagon and the goons find themselves handcuffed.

A few seconds later Cassie and Riri speak through the com, announcing they've successfully dismantled the hijacking device that had been hooked to the engine. David, Billy and Eli's congratulations and jokes mix with the rest of the team's on the open channel. America grins, finally able to remember.

"The first time we had a fight on a train was after Tommy and Billy's twenty-first birthday, right?"

Everyone hums their affirmatives and Riri announces that now they've got to tell her that story, since she joined the team later. Eli adds that he was still at college and he's never gotten the full version of that anecdote, and they all agree to go get breakfast for it.

America kicks a portal on the wagon's floor, and calls over the com, "Kaplan, get your ass here, help me float these dicks to SHIELD's headquarters so we can go get food!"