When a new inmate at the Utah State Prison claims he cannot remember the crime that sent him to prison, Dr Carlisle's experiments with hypnosis reveal a violent alternate personality hidden just beneath the surface.

Dr Carlisle's Mormon faith is tested when Arthur Gary Bishop asks for his help in understanding how he became a serial killer.

Dr Carlisle discovers a surprising link between the traumas of war and the development of the violent mind when he interviews a Vietnam War veteran turned killer.