Dr. Melcher/ Monsieur Colomb
Bela Lugosi
FBI Agent Richard ‘Dick’ Martin
Clayton Moore
Stevens
Joseph Eggenton
The Dragon
I. Stanford Jolley
FBI Agent
Frank Melton
Alice Saunders
Joan Barclay
Dr. William Saunders
George Pembroke
Amos Hanlin
Robert Frazer
Phillip Wallace
Robert Fiske
John Van Dyke
Irving Mitchell
Ryder
Edward Peil Sr.
FBI Chief Colton
Kenneth Harlan
Kearney
Max Hoffman Jr.
Director
William Nigh
Producer
Sam Katzman
Music
Johnny Lange
Director of Photography
Arthur Reed
Production Manager
Jack Dietz
Editor
Carl Pierson
Sound Engineer
Glen Glenn
Art Direction
Dave Milton
Lew Porter
Heinz Roemheld
Assistant Director
Gerald Schnitzer
Arthur Hammond
Original Story
Harvey Gates
Story
Robert Kehoe
Screenplay