When a beautiful young medium is found dead in mysterious circumstances, Dr Max Liebermann, is called upon by Inspector Oskar Rheinhardt of the Vienna Police to assist in the search for the killer.

Max's engagement party is interrupted by news of a grotesque series of murders in Vienna's slums. Oskar quickly arrests a suspect and finds circumstantial evidence to support a conviction. But Max isn't convinced they've got the right man.

Max's nephew suffers a breakdown after the drowning of a fellow cadet at a military academy. The police department refute suspicions but Max shows Oskar a pattern of violence and believes that they're looking at a murder investigation.