The Testament of Dr. Mabuse (German: Das Testament des Dr. Mabuse), also called The Last Will of Dr. Mabuse, is a 1933 German crime-thriller film directed by Fritz Lang. The movie is a sequel to Lang's silent film Dr. Mabuse the Gambler (1922) and features many cast and crew members from Lang's previous films. Dr. Mabuse (Rudolf Klein-Rogge) is in an insane asylum where he is found frantically writing his crime plans. When Mabuse's criminal plans begin to be implemented, Inspector Lohmann (Otto Wernicke) tries to find the solution with clues from gangster Thomas Kent (Gustav Diessl), the institutionalized Hofmeister (Karl Meixner) and Professor Baum (Oscar Beregi Sr.) who becomes obsessed with Dr. Mabuse.