Bela Lugosi
Dr. Feodor Orloff / Prof. John Dearborn
Acting
Hugh Williams
Det. Insp. Larry Holt
Acting
Greta Gynt
Diana Stuart
Acting
Edmon Ryan
Lieutenant Patrick O'Reilly
Acting
Wilfred Walter
Blind Jake
Acting
Arthur E. Owen
Dumb Lou
Acting
Alexander Field
Fred Grogan
Acting
Gerald Pring
Henry Stuart
Acting
O.B. Clarence
Prof. John Dearborn (voice)
Acting
May Hallatt
Police Constable Griggs
Acting
Bryan Herbert
Police Sgt. Walsh
Acting
Charles Penrose
Morrison, undercover detective
Acting
Julie Suedo
Orloff's Secretary
Acting