using the outline that lang proposed, jacques signed a contract in july 1931 for the movie to be written by von harbou and directed by lang based on lang's own outline. the film was released in tandem with jacques's book. jacques' contributions are not mentioned in the film. "the testament of dr. mabuse" is a direct sequel to "dr. mabuse the gambler" and is related to the film "m" which features the inspector lohmann character.