Michael Heathley
James Donald
Lydia Heathley
Phyllis Calvert
George Jackson
Herbert Lomas
Fisher
Geoffrey Denton
Inspector Carter
Cyril Chamberlain
Agent Lawson
Hal Osmond
Dr. Ferguson
Caven Watson
Maisie
Marianne Stone
Prof. Adams
Stanley Maxted
General Adams (uncredited)
Hartley Power
Sentry (uncredited)
Philip Ray
Jim Barnes (uncredited)
Johnnie Schofield
Dr. Dennis Bord
Noel Willman
Ted (uncredited)
John Warren
Dr. Alex Leon
Herbert Lom
Maj. Sam Seagram
Robert Beatty
Brian Jackson
Patric Doonan
Sir Charles Craddock
Walter Fitzgerald
Caroline Cartier
Muriel Pavlow
Prof. Carrington
Maurice Denham
Michael's Mother
Marjorie Fielding
Assistant Director
George Pollock
Director
Anthony Asquith
Costume Design
Julie Harris
Executive Producer
Earl St. John
Special Effects
Bryan Langley
Editor
Frederick Wilson
Original Music Composer
Benjamin Frankel
Art Direction
John Howell
Continuity
Yvonne Axeworthy
Makeup Artist
W.T. Partleton
Director of Photography
Desmond Dickinson
Production Controller
Arthur Alcott
Camera Operator
H. A. R. Thomson
Bill Warrington
Conductor
Muir Mathieson
Production Manager
Hugh Attwooll
Albert Whitlock
Sound Editor
Harry Miller
Producer
Antony Darnborough
Sound Recordist
John Dennis
Gordon K. McCallum
Aerial Director of Photography
Stanley Grant
Screenplay
William Fairchild
Writer
John Pudney