Fritz Lang	...	(Director)
Thea von Harbou, Fritz Lang, Egon Jacobson	...	(Writer)
Peter Lorre	...	Hans Beckert
Ellen Widmann	...	Frau Beckmann
Inge Landgut	...	Elsie Beckmann
Otto Wernicke	...	Inspector Karl Lohmann
Theodor Loos	...	Inspector Groeber
Gustaf Gründgens	...	Schränker
Friedrich Gnaß	...	Franz
Fritz Odemar	...	The Cheater
Paul Kemp	...	Pickpocket with Six Watches
Theo Lingen	...	Bauernfänger
Rudolf Blümner	...	Beckert's Defender
Georg John	...	Blind Panhandler
Franz Stein	...	Minister
Ernst Stahl-Nachbaur	...	Police Chief
Gerhard Bienert	...	Criminal Secretary
Fritz Arno Wagner	...	Cinematographer
Paul Falkenberg	...	Editor

Summary: In Germany, Hans Beckert is an unknown killer of girls. He whistles Edvard Grieg's 'In The Hall of the Mountain King', from the 'Peer Gynt' Suite I Op. 46 while attracting the little girls for death. The police force pressed by the Minister give its best effort trying unsuccessfully to arrest the serial killer. The organized crime has great losses due to the intense search and siege of the police and decides to chase the murderer, with the support of the beggars association. They catch Hans and briefly judge him.