Captain America: Civil War
With Sharon Carter's help, Captain America and Falcon find Bucky living a normal life in Bucharest, Romania. Steve meets Bucky and tries to make him remember that he is his old friend, but Bucky tells him to leave. When the cops show up and attack them, Bucky runs away and Steve and Sam follow him. Black Panther shows up and also chases Bucky, trying to kill him. There is a big chase, which leads to the cops and James Rhodes/War Machine arresting Steve, Bucky, Sam, and Black Panther, who takes off his mask to reveal that he's T'Challa.