Richard Greene

as Sir Ronald Burton / Richard Beckett

Boris Karloff

as Dr. Meissen

Stephen McNally

as Count Karl von Bruno

Rita Corday

as Countess Elga von Bruno

Lon Chaney Jr.

as Gargon

John Hoyt

as Count Steiken

Michael Pate

as Count Ernst von Melcher

Nancy Valentine

as Therese von Wilk