Detectives Goren and Eames investigate the murder of a bisexual woman who is found slain in a hotel room.

At first, Goren and Eames note the murder has the distinctive characteristics of one committed by an imprisoned serial killer, raising fears that he has found an accomplice to carry on his work while he is in prison. The investigation leads them to a human behavior research institute, where they discover that a series of experiments has being developed on the man to discover the main cause of his insanity.

Then, the detectives interview the institute's director; an arrogant doctor who struggles for public and scientific credibility, and his research assistant; a shy woman who might have fallen under the killer's spell and committed the copycat murder. Nevertheless, while D.A. Carver stalls to prevent the release of the imprisoned man, Goren and Eames discover an evidence that might point toward a most unlikely ending.