Bran Marshall flees to Rhea, a neighbouring planet that is now hostile to "Earthers" after Earth is nearly destroyed. After escaping onboard a Rhean supply ship, he discovers the crew has been slain, with Ohsha, a female warrior, as the sole survivor. The ship is battered by meteorites as the two strive to murder each other. Bran and Ohsha must work together to save the craft before it crashes into the planet below— and the people who dwell there.