Boris KarloffDr. Janos Rukh
Bela LugosiDr. Felix Benet
Frank LawtonRonald Drake
Frances DrakeDiana Rukh
Violet Kemble CooperMother Rukh
Beulah BondiLady Arabella Stevens
Walter KingsfordSir Francis Stevens
Paul WeigelMonsieur Noyer
Frank ReicherProfessor Meiklejohn
Georges RenaventChief of the Surete
Lambert HillyerDirector
John ColtonScreenplay
Howard HigginOriginal Story
Douglas HodgesStory
Edmund GraingerProducer
Fred S. MeyerExecutive Producer