Some of the b-roll of superheroes are sent into a trap by crooked CIA director Valentina Allegra de Fontaine (Julia Louis-Dreyfus). After they escape, the go to confront her only to find that de Fontaine's new and improved hero/weapon Sentry has a dark side threatening the entire world. With the Avengers otherwise occupied, saving the Earth from a deadly menace falls to a group of antiheroes. But their call to action may well turn out to be another fiendish trap.