If Steve is missing his own shield, then the sounds coming from the training room should perhaps delight him - because that is, indeed, the very distinct sound of Captain America's shield hitting targets and bouncing back, being caught, spun into another throw. Underlying that, the sounds of someone moving around, feet fast on the mats in the training room, jumping and lunging with the presumed motions of the shield, vibranium practically singing.

And if Steve follows these sounds, what he'll find is Sam, training with the shield. He looks like he's been at it for a while, both arms beginning to show the faint signs of bruises, because Sam pushes himself. He catches the shield mid-air, landing on a flip, and nearly stumbling when the motion brings him to face the entrance of the room - and with it, one Steve Rogers.

And Sam is... stunned, for a moment, just standing there mid-workout, shield on his arm, with Steve Rogers across from him. Steve who left to travel back in time half a year before Sam came to the station. Steve who's been on the station, briefly, and vanished. Just another friend and partner Sam keeps gaining and losing, because the universe plays cosmic jokes on him like that.

"I feel like one of us should break the tension by saying 'On your left', huh?"