In 1984, police in Washington State are investigating a spate of serial murders committed by a mysterious man known as The Green River Killer. With no leads to go on, the detective in charge of the case consults with psychologists in an attempt to get inside the mind of the killer. But when that doesn't produce a positive result and the killings continue, the detective realises that the only way to understand what makes a serial killer tick is to meet one. So he visits the imprisoned Ted Bundy, one of the most notorious serial killers in American history. The detective has his resolve tested as he gets a disturbing insight into the murderous mind, but when the information Bundy provides assists the hunt for the Green River Killer the detective perseveres. Eventually he builds a twisted relationship with Bundy which forces the detective to confront his own psychological demons before he finally comes face to face with the Green River Killer.