Columbo finds himself under observation by a world-famous sex therapist when he investigates her lover’s murder at the clinic, and tries to track down the suspected murderess — a phantom “lady in black”.
Columbo is called to the Allenby Sex Clinic where David Kincaid has been murdered in the clinic’s therapy bedroom facility. He finds a cigarette with lipstick on it and notices a second set of blood stains. Dr. Joan Allenby, David’s lover and business associate arrives and Columbo notices her coat still has a price tag on it. Joan is a well known sex therapist with a radio program and a television deal, but may know more about the crime than she initially offers.