DCI Cassie Stuart and DI Sunny Khan face an impossible cold case. A lawyer. A nurse. A schoolteacher. A police officer. These four suspects are the pieces of the puzzle. But as Cassie and Sunny put this picture together, the more blurred it becomes. The investigation will question their assumptions about the most damaged and destructive in society. When a victim becomes a criminal, is punishment the same as justice?

When human remains are found by a highway, Cassie and Sunny are called to the scene. Dogged work leads the team to Hayley Reid, a 16-year-old girl who went missing on the eve of the millennium. The police's failure to find out what happened to Hayley wrecked her family's life. Cassie is determined to correct the mistakes made by the original investigating team, no matter the personal cost.