In the lawless outer reaches of the galaxy, the cocky Terran scavenger Peter Quill (Nathan Fillion), known only to himself as Star-Lord, lives by his wits and the 90s alt-rock anthems on his Walkman. After stealing a mysterious and powerful orb, he becomes the galaxy's most wanted man, hunted by the relentless Kree fanatic Ronan the Accuser (Daniel Day-Lewis). To escape, Quill is forced into an uneasy alliance with a bizarre group of cosmic outlaws: Gamora (Kate Beckinsale), the deadly, conflicted daughter of a cosmic tyrant; Drax (Dwayne "The Rock" Johnson), a hulking warrior driven by a singular thirst for vengeance against Ronan; and the inseparable bounty-hunting duo of Rocket (voiced by Steve Buscemi), a wisecracking, genetically-engineered raccoon, and Groot (voiced by Morgan Freeman), his sentient tree bodyguard.
When they discover the orb contains an Infinity Stone, a weapon of unimaginable destruction that Ronan intends to use to cleanse the planet Xandar, their selfish quest for survival turns into a desperate mission. The Guardians must put aside their greed and grievances and rally the ragtag Ravager fleet for a last-ditch battle to stop Ronan's genocidal crusade. This band of outlaws, losers, and misfits might just be the galaxy's only hope, if they don't kill each other first.