Till the end of the line

Continuation to You can t fix it. AU where Loki has joined the Avengers after falling in love with Tony Stark. After helping Loki and Tony to fix their relationship at a high personal cost Steve is called by Clint to join him and Natasha in a mission to track the Winter Soldier. He s unaware that the Winter Soldier is no one else that his long lost best friend and "Bucky" Barnes.