Savannah has grown up preparing for the end of the world. Her father is Teddy Unser, ex-con and doomsday prepper devoted to the day he and his family will have to run. But Teddy is tired of waiting, and when Savannah is fourteen, he steals a water truck and commits a cataclysmic attack in which Savannah and her little sister M a find themselves accomplices. Teddy flees with the girls and their grandmother into a macabre refuge inside a labyrinth...