sherloques:

Captain America: The Winter Soldier Audio Commentary:

“This is the revelation of Bucky. We wanted to do it when the whole world was falling in on Steve. To find out that the one thing he thought he knew was not even true was like having the final rug pulled out from under him. The worst thing that could happen to Steve is “my best friend, who I thought was dead, is a killing machine”. It’s so rare that you have such an emotional connection between a hero and a villain. Best friends turned into mortal enemies is in a way even more tragic.”