The AMC series revolves around the murder in Seattle of a teenage girl, Rosie Larsen, and the gripping police investigation it sparks. The facts of the case unfold against a backdrop of local politics, high school scandal, and a grieving family flattened by tragedy. As leads turn cold and suspects multiply, the detectives race against time to find Rosie’s killer. They soon discover that everyone is a suspect, every suspect has a secret, and every hour counts.