While attempting to solve the Storyville district murders in 1910 New Orleans, Detective Brian Donahue comes under pressure by his superiors and local 'political machine' and enlists the aid of Dr. Eric Trevor, a psychiatrist at the nearby Saint James Infirmary, a hospital for the mentally ill. Dr. Trevor is at first reluctant to join, his main concern is for his patients, not the police's work but understands his value to the investigation. As he evaluates the mounting crime scenes, he begins to formulate his own idea of why the crimes are occurring and that perhaps it was not the prostitutes that were the intended victims but actually their customers.
