A serial killer is at large in Yorkshire, cutting off one victim's body part to leave with the next.

The police turn to forensic psychologist and profiler Dr Jo McCready, who knows the killer's M.O. all too well. Twenty-five years ago, notorious Yorkshire serial killer Jacob Malecki murdered fifteen people using the same method, and Jo provided the profile that led to his capture.

But with Malecki locked up in prison, who is the copycat killer? As the bodies pile up and the police get desperate, Malecki offers to help with the case. After all, who better to find a copycat than the original?

Now Jo must play a dangerous game of cat and mouse with both killers. Can she use one to catch the other before more people die?