A new ally joins forces with Steve, Natasha, and Sam as they struggle to expose a conspiracy. They soon find themselves up against an unexpected and formidable enemy - The Winter Soldier. Both the Captain and Cass have a history with him and it further complicates their heroic attempts to save the world from an old threat.

The Winter Soldiers memory was always taken from him. The one time he chose to give them up was after an encounter with a woman who was equally as tortured, so when he crosses paths with her in the future he has no recollection of her. However, her memories of him, untampered with, could never be forgotten.