The film was an unauthorized adaptation of Robert Louis Stevenson's novel The Strange Case of Dr. Jekyll and Mr. Hyde, but the source material went unrecognized by some of the German media due to changes in the characters' names. Released in 1920, this is one of Murnau's lost films. While the film itself does not survive, the scripts and related production notes do. Because the film is lost, its full length is unknown. Dr. Warren is the Dr. Jekyll character who changes into Mr.