You were also on the Winter Soldier Program, having received the serum and been trained and wiped. You managed to escape a little while back, seeking refuge with the Avengers, helping to take down other Hydra bases using what you could remember, in exchange for protection and help in recovering.
One day, you had a flashback. Not a brutal one, filled with pain, no - instead, you saw someone. The Winter Soldier - not one of the other Soldiers, him. A memory - training with him. He had you in an arm lock, before harshly shoving you to the ground. Then the scene changed, and you were in a cell, sat on the cold, hard floor. The Soldier sat opposite you, staring at the ground, his metal arm limp and deactivated, chained up tightly. But he wasn’t the Soldier. It was him, the man beneath all the conditioning. Then it faded into a blur, and you remembered no more.
Following this, you knew you had to help him. For gods sakes, if he’d been through what you’d been through, maybe even worse, you had to. You discussed with the team, and you set out on a mission. To find the facility he was being kept in.
It seems like today is your lucky day. Having split off from Nat and Steve, going solo but keeping in touch through comms, you follow the directions in fading paint on the wall - ‘CELL BLOCK —>’. The arrow lead you through a double door to a hallway, lined with cells either side. It was dead silent. Your boots quietly clicked on the stone floor, swinging your head from side to side, scanning each cell. And then you saw him.
Sat in a cell, slumped against the wall, metal arm chained just like in your memory, was the Soldier. Actually, he looks a lot like Steve’s old friend, Bucky, except he has deep, dark circles under his eyes and he looks utterly starved… Nevermind. For now, you have to get him out of here.