Diretor/a
Anthony Asquith
DIRETOR/A
Elenco (na ordem dos créditos)
Phyllis Calvert
Lydia Heathley
James Donald
Prof. Michael Heathley
Robert Beatty
Maj. Sam Seagram
Herbert Lom
Dr. Alex Leon
Muriel Pavlow
Caroline Cartier
Noel Willman
Dr. Dennis Bord
Walter Fitzgerald
Sir Charles Craddock
Patric Doonan
Brian Jackson
Maurice Denham
Prof. Carrington (project director)
Marjorie Fielding
Mother Heathley
Caven Watson
Dr. Ferguson
Herbert Lomas
George Jackson
Hal Osmond
Agent Lawson
Geoffrey Denton
Fisher
Cyril Chamberlain
Insp. Carter
Marianne Stone
Maisie
Tucker McGuire
Myrna (scenesDeleted)
Stanley Maxted
Prof. Adams
Douglas Bradley-Smith
Control room operator (uncredited)
John Carew
Security policeman (uncredited)
Patricia Glyn
Mabel (uncredited)
John Lorrell
John Martin
Hartley Power
General Adams (uncredited)
Philip Ray
Sentry (uncredited)
Johnnie Schofield
Jim Barnes (uncredited)
John Warren
Ted (uncredited)