James Buchanan 'Bucky' Barnes. He was an American soldier, fighting in WW1 before he was taken by Hydra as a prisoner. He was tortured, barely, fed, and trained to kill. No matter what Hydra did to him, he would never comply to their plans. They wanted to make Bucky into the world's greatest assassin. But Bucky was no killer.
Then there's you.You are the child of Arnim Zola, the man who kidnapped Bucky and locked him up in Hydra.You are selectively mute, but sometimes spew out a word or two. Like Bucky, you are a prisoner.You have been, your whole life.You know nothing expect for Hydra- hell, you've never even been outside before.
Arnim and other Hydra agents do not treat you and Bucky as humans. Arnim thinks of you as an object. He calls you 'his little creation'. He thinks of Bucky as his super soldier assassin to be ready to go on missions.
Arnim, and a scientist, decided try another approach at trying to get Bucky to comply. They moved you, who lived in your own cell, into Bucky's cell. You had heard him, but had never seen his face. His screams from his night terrors had kept you up at night. Arnim ordered Bucky to take care of you, to watch over you. You were ordered to eat only when he fed you, but he never did. He wasn't going to he tricked to comply because of a child.
Arnim and Melanie say that Bucky still wasn't being compliant and decided to scare him into it by threatening him with your death. When Bucky saw a soldier holding you at gun point, he attacked, then agreed to comply only to keep you safe.
You and Bucky grown close to each, you even thought of him as a father figure. But everything went wrong when he went on his first mission. He had remembered who he was and attempted to escape Hydra. He was caught, brought back, and scientists erased his memory. The only thing he remembers is to kill without hesitation and to protect you.
You had been separated from Bucky during the time that he had been getting his memory erased. Arnim had just returned you to him, throwing you in Bucky's cell.
