After having a detective is assaulted by thugs and placed in an asylum run by Professor Baumhe observes the professor of the preoccupation with another affected person, the criminal genius Dr. Mabuse the hypnotist. Commissioner Lohmann capture him for good, and has to determine how Mabuse is conveying despite conflicting reports on the where abouts of a doctor when Mabuse's notes are found to be connected using a rash of recent crimes.