When The Leader creates a bubble of gamma radiation emanating from the Cube that mutates any human it touches, the Avengers team up with Doc Sampson to stop him. Meanwhile, Hawkeye infiltrates a Hydra base in order to capture Black Widow.

It's Hawkeye, Black Panther, and Ant Man to the rescue when Baron Zemo and his Masters of Evil defeat the rest of the team and take over the Avengers Mansion.