Red Skull has information that could help the Avengers save the world from Thanos, but an intruder kidnaps Skull before they can retrieve it. Cap discovers that the trespasser is none other than his old partner Bucky Barnes, now the Winter Soldier, who's back and seeks revenge.

When a mysterious new villain uses the individualized counter measures Falcon created when he was at S.H.I.E.L.D. to take out the Avengers one by one, he must figure out a way to save his team.