For twenty-five generations, the last of the human race has lived underground on an unnamed rocky planet that orbits a small white dwarf star. They call their settlement Karth, and although there has been a collective longing to return to the familiar blue planet, both the knowledge and the technology to return has been lost. Until now. Justine discovers Earth may not be a desolate and lifeless world, long forgotten, after all. Her insatiable curiosity, sense of adventure and intractable defiance takes her on a journey to unlock the mysteries of the lost home she has never known.