Nineteen years ago, a parasitic fungal outbreak killed the majority of the world's population. In one of the few remaining quarantine zones, thirteen-year-old Ellie begins her new life as a ward of a military boarding school, where a friendship with fellow student Riley leads to her first trip into the outside world. Beyond the walls of the regimented civil order they know, Ellie and Riley are soon confronted with the violent way of life of the insurgent group the Fireflies--and with the monstrous victims of infection!