A young woman's body has been found on Hampstead Heath. Naked, tortured, mutilated. The violence inflicted shocks even seasoned forensic pathologist Kate Walker. And when DI Jack Delaney takes on the case, he realises that someone is taunting him with the horrific murder. Then, in a north London flat, the expertly dissected body of a second young woman is discovered. There is no apparent connection between the victims, but it becomes clear that a serial killer is on the loose - and that Kate could be next. As violent events from Jack's past catch up with him, and not for the first time he has to make a choice between the living and the dead. Only this time, he gets it horribly wrong...