A retired rock star, Johnny Boz, is stabbed to death with an ice pick during sex by a mysterious blonde woman at his apartment. Homicide detective Nick Curran investigates, and the only suspect is Catherine Tramell, Boz's bisexual girlfriend and a crime novelist who has written a novel that mirrors the crime. It is concluded that either Catherine herself did it or someone trying to frame her out of spite. Tramell is uncooperative and taunting in the investigation, smoking in the interrogation room and exposing her bare genitalia in front of the officers. She presents alibis and passes a lie detector test. Nick discovers that Catherine has a habit of befriending murderers, including her girlfriend Roxy, who is later shown to have murdered several young boys on impulse, and Hazel Dobkins, who murdered her family.