Boris Karloff
James Lee Wong
Grant Withers
Police Capt. Sam Street
Evelyn Brent
Olga Petroff / Countess Dubois / Sophie Dome
John St. Polis
Carl Roemer
William Gould
Theodore Meisle
Hooper Atchley
Christian Wilk
John Hamilton
Simon Dayton
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)
