A group of juvenile delinquents are sent from an ageing space station, where the remnants of humanity have lived for generations following a nuclear apocalypse, down to Earth to determine whether the planet has become habitable again. Upon landing, they discover that survival on the ground is far more dangerous and morally complex than they had anticipated, as they encounter other survivors who never left. The series follows their struggle to build alliances, navigate brutal conflicts, and make increasingly difficult ethical choices in a world where the old rules no longer apply.