Nick Franco is a violent, two-timing gigolo and his current paramour, Laura Stanton, has had enough. With the help of a young woman named Lisa, she murders her lover and sets herself up with an airtight alibi. When Columbo starts sniffing on her trail, Laura quickly works to seduce the married detective, hoping that her sex appeal will throw the usually stubborn Lieutenant off the scent.

Graham McVeigh, a thoroughbred ranch owner, kills his brother, and frames a local mob bookie. Then, under the guise of making good on his brother's debt, he kills the bookie as well, claiming self-defense. Mob boss Vincenzo Fortelli starts to exert pressure on McVeigh. To solve the crime Columbo must work with the gangster.

Cathleen Calvert and her lover, crime scene investigator Patrick Kinsley, plot to get rid of Calvert's husband, Clifford, a powerful businessman, by killing an investment broker with whom he is currently feuding, and pinning the murder on Clifford. As long as he is alive and in prison, Cathleen has access to all his money. Columbo must uncover a criminal who is part of the team handling the investigation.