The first victim is a young woman found on Hampstead Heath. Her throat has been slashed and her body mutilated. This horrifying discovery marks the beginning of Detective Inspector Jack Delaney's toughest ever case. When the expertly dissected body of a second young woman is discovered in a north London flat with a brightly coloured scarf tied around her neck, it suddenly becomes clear that a psychopath is on the loose. There is no apparent connection between the two victims and there are no clear motives - but the crime scenes tell a terrifying story. Delaney, together with forensic pathologist Kate Walker, needs to act quickly and piece together the evidence in order to uncover the deadly pattern behind the murders. However, violent events from Delaney's past are threatening to catch up with him, and he must stay one step ahead of his enemies if he is to stop the killer from striking again.