Brash adventurer Peter Quill finds himself the object of an unrelenting bounty hunt after stealing a mysterious orb coveted by Ronan, a powerful villain with ambitions that threaten the entire universe. To evade the ever-persistent Ronan, Quill is forced into an uneasy truce with a quartet of disparate misfits — Rocket, a gun-toting raccoon, Groot, a tree-like humanoid, the deadly and enigmatic Gamora and the revenge-driven Drax the Destroyer. But when Peter discovers the true power of the orb and the menace it poses to the cosmos, he must do his best to rally his ragtag rivals for a last, desperate stand.
Their stories converge in the space prison Kyln. After the characters break out, they venture to Knowhere (the severed head of a celestial being that serves as a hangout for aliens) and visit the weird menagerie of the Collector (Benicio Del Toro). They also have to avoid two villains, Ronan (Lee Pace) and Nebula (Karen Gillan), who are in hot pursuit of Quill's orb, which has the power to destroy the galaxy.