One day, Ratchet, a Lombax (yellow, human-like creature), witnesses a spaceship crash on his home planet of Veldin. The ship was piloted by Clank, a small robot, who had escaped from his home planet Quartu, shortly after his creation, as he discovers the horrible truth of evil plans to destroy the galaxy by Chairman Drek, whose home planet is so polluted and uninhabitable that he forms a cunning plan to extract chunks of existing planets in order to create a new 'superplanet'. When Clank shares this information with Ratchet, Ratchet agrees to help Clank take down Drek, fuelled by a lifelong desire to go an interplanetary adventure to follow his idol Captain Qwark. Flying from planet to planet, Ratchet and Clank build up an incredible arsenal of weapons in the hope of catching up and taking down Drek. However, he soon discovers that Drek intends to destroy Ratchet's home planet, Veldin. Will Ratchet and Clank stop Drek before it's too late?

After a generation of peace, the Earth Federation has begun to build new space colonies to house humanity's growing population...