The Guardians of the Galaxy must keep the Build Stone safe from being captured by the likes of Ronan, Nebula, and Yondu and the Ravagers, who appear out of a portal in space.
Star-Lord and Gamora tumble through a portal and end up in the middle of Knowhere, with Ronan, Yondu and Taserface hot on their trail.
Gamora drops out of a portal to find Drax stalking Thanos in an attempt to do what he does best: destroy.
After a fall through a portal strands them on the forest planet, Berhert, Rocket and Groot witness Ronan making a deal with Yondu and Taserface and realize they must intervene.
Thanos, Ronan, Nebula and the Ravagers all seek to possess the Build Stone and the fate of the universe depends on the Guardians of the Galaxy.