Casts
Boris Karloff
James Lee Wong
Grant Withers
Police Capt. Sam Street
Maxine Jennings
Myra Ross
Evelyn Brent
Olga Petroff / Countess Dubois / Sophie Dome
George Lloyd
Devlin
Lucien Prival
Anton Mohl
John St. Polis
Carl Roemer
William Gould
Theodore Meisle
Hooper Atchley
Christian Wilk
John Hamilton
Simon Dayton
Wilbur Mack
Russell
Lee Tung Foo
Tchin
Lynton Brent
Tommy
Grace Wood
Mrs. Roemer
Frank Bruno
Lescardi (uncredited)
Ed Cassidy
Ambulance Doctor (uncredited)
Wheaton Chambers
Chemistry Lab Director (uncredited)
Clancy Cooper
Warehouse Man (uncredited)
George DeNormand
John (uncredited)
Lester Dorr
Coroner (uncredited)
Herbert Evans
Wilk's Butler (uncredited)
Dick Reinhart
Dock Worker (uncredited)
Crews
William T. Lackey
Producer
William Nigh
Director
Houston Branch
Screenplay
Scott R. Dunlap
Producer
Scott R. Dunlap
Production Manager
Karl Zint
Recording Supervision
Russell F. Schoengarth
Editor
Hugh Wiley
Original Story
Harry Neumann
Director of Photography
Edward J. Kay
Original Music Composer
Charles J. Bigelow
Production Manager
Gordon Bau
Makeup Artist
Harry Grundstrum
Props
Abe Meyer
Music Director
E.R. Hickson
Technical Supervisor
W.B. Eason
Assistant Director