What starts with the gruesome discovery of a severed head on the Tube soon becomes personal for former DI Cal Drake. After one betrayal too many, Drake has abandoned the police force to become a private detective. He's teamed up with enigmatic forensic psychologist Dr Rayhana Crane and it's not long before the case leads them to the darkest corners of the nation's capital and in dangerously close contact with an international crime circuit, a brutal local rivalry and a very personal quest for retribution. With the murder victim tied to Drake's past, his new future is about to come under threat.