This is the third day he's sat here. Same building, same window. He's always surprised by how vulnerable his targets allow themselves to be.
The Winter Soldier sights down his scope, adjusting the barrel slightly. The feeling soothes him, fills in his ragged patches of memory a thousand times over. Carefully, like he would a lover, he rests his cheek against the metal and exhales.
His target moves calmly, no armor in sight. The woman, the one he's seen over and over again, is still between them but the rounds he's loaded would punch through a bulletproof window, her, and the target at the same time. Maybe another bulletproof window on the way out as well, if the wind was right.
The Winter Soldier closes his eyes briefly, opens them once again to watch the target, squeezes his finger gently against the trigger but doesn't fire. He sighs and something stops him.
Bucky grimaces then and lets his posture relax. A thousand meters away, Tony Stark pours another drink. A thousand meters away, Pepper Potts (a redhead, which seems familiar somehow) leans in for another kiss.
Bucky lets the muzzle drop slightly, lets himself sag back against the wall. He can't lose himself in the gentle squeeze of the trigger, not anymore. Something's stopping him. It's the same foolish part of him (that curious, wretched, not entirely damned part) that made him pull Rogers from the water.
Bucky closes his eyes and tips his head back against the wall. He can't do it. He can't make the shot. The realization hits him painfully, but at least it's an honest one.
A thousand yards away, Tony Stark drains a glass. A thousand yards away, Pepper Potts shakes her head in exasperation at a joke.
Here, Bucky Barnes lets his final target live.