Everybody carries emotional baggage throughout their lives…and most resolve their issues. 

But what if one individual won’t let go of a longstanding grudge…and enacts a murderous revenge scheme. 

Detective Inspector John Mahoney is confronted with a serial killer intent upon squaring up with his victims in an elaborate and brutal manner. Mahoney and his team in the Serious Crimes Squad must harness the insights of a forensic psychologist to unravel the mindset of their calculating and ruthless foe if the mayhem is to be halted…and if he is to save one of his own.