Calificación
Reparto

Boris Karloff
Dr. Laurence

Anna Lee
Dr. Clare Wyatt

John Loder
Dick Haslewood

Frank Cellier
Lord Haslewood

Donald Calthrop
Clayton

Cecil Parker
Dr. Gratton

Lyn Harding
Prof. Holloway

Clive Morton
Journalist

D.J. Williams
Landlord