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

Tudor Owen as Romley

Henry Corden as Fender

Otto Waldis as Innkeeper Krantz

Roy Engel as Burgher

Leslie Denison as Sir David Layton (uncredited)

Bernard Szold as Koppich (uncredited)

Jack Perrin as Hunter (uncredited)

Forrest Burns as Guard (uncredited)

Chuck Hamilton as Guard (uncredited)

John Roy as Guard (uncredited)

Victor Romito as Guard (uncredited)