When two bodies are found brutally murdered at a building site in Battersea, DS Cal Drake is first to the scene. He sees an opportunity: to solve a high-profile case and to repair his reputation after a botched undercover operation almost ended his promising career in the Violent Crimes Unit. Assigned to work with the forensic psychologist Dr Rayhana Crane, and on the hunt for an elusive killer, Drake's investigations lead down the dark corridors of the past - to the Iraq war and the destruction both he and Crane witnessed there. With a community poised on the brink of violence, Crane and Drake must put their lives on the line to stop the killer before vengeance is unleashed.