Calificación
Reparto

Boris Karloff
Prof. Morlant

Cedric Hardwicke
Broughton

Ernest Thesiger
Laing

Ralph Richardson
Nigel Hartley

Dorothy Hyson
Betty Harlon

Anthony Bushell
Ralph Morlant

Kathleen Harrison
Kaney

Harold Huth
Aga Ben Dragore

D.A. Clarke-Smith
Mahmoud

Jack Raine
Davis the Chauffeur (uncredited)

George Relph
Doctor (uncredited)