When Bucky receives a message from Natasha saying she's being hunted, he doesn't hesitate to answer the call of his fellow Avenger. Aided by Hawkeye, he follows a series of clues that lead not only to Natasha, but also to a deadly web of secrets and a series of events that will either make him stronger ... or completely destroy him.

Mere days after their defeat at Loki's hand, the Avengers must assemble for a mission that will take them across the galaxy as they form alliances and try to stop an enemy worse than any they've faced so far.

The Avengers are looking forward to a peaceful Christmas - until a supervillain jailbreak turns their night before Christmas into a mission to remember.