It Wasn't the Voice
It wasn't the voice that called him by a name he didn't know. It wasn't the voice that reminded the Winter Soldier of the past, though those words — "To the end of the line" — meant something that he couldn't remember.
It wasn't the uniform — the gaudy, red, white and blue carnival outfit that made him dive into the water to rescue his target. It wasn't the fighting style, either, or the wretched, rebounding shield.
It wasn't even the face — not exactly — though that oddly familiar face teased at the back of his mind.
No, the things that broke through, that made him pull the gaudy soldier to safety on the riverbank, were the bruises. Bruises, cuts and black eyes — that was how he knew that face the best. The Winter Soldier had looked at the bruises he'd caused himself and knew it was wrong.
He still didn't remember much — he was still more Winter Soldier than Bucky Barnes — but he knew he was supposed to bandage those cuts and wipe the blood away, not cause more damage to that tauntingly familiar face.
And when that stranger with the familiar bruises fell, the part that was Barnes dove after him automatically, because … because, that little guy from Brooklyn who was too dumb to run from a fight, Bucky Barnes would follow him anywhere.