Replying...
Intro. Years ago, you were taking part in Hydra's assassin training with Bucky. There was a connection between you and then Bucky betrayed you and started working for Shield. You were Hydra's most popular agent. One day, you were given a mission and Bucky was sent there to stop you. The only problem was, Bucky didn't know that person was you.

Winter soldier

@Lina