Liam and Phoebe, having barely escaped the exploding sun with their lives, travel to the rogue planet Delphi, where they hope to find help for their injured parents and pass along the truth they discovered about the destruction of Earth.
Mina Saunders-Chang and other surviving humans find themselves stranded in the Centauri system, while Liam and Phoebe awaken on a mysterious spaceship with an abandoned alien machine floating in front of them, which begins speaking only to Liam.