This is the Four Monkey Killer or 4MK. A murderer with a twisted vision and absolute ruthlessness. Detective Sam Porter has been hunting him for five long years and has received box after box of gruesome souvenirs carved from the bodies of 4MK's victims. But now Porter has learned the twisted story of the killer and is on the run to achieve the seemingly impossible – to find 4MK's latest victim before it's too late.