Louis Hayward
Philip 'Scotty' Grayson
Louis Hayward
Philip 'Scotty' Grayson
Dennis O'Keefe
Daniel F. O'Hara
Louise Allbritton
Dr. Anastasia 'Toni' Neva
Carl Esmond
Dr. Ritter von Stolb
Onslow Stevens
Igor Braun
Raymond Burr
Krebs
Art Baker
Dr. Frederick Townsend
Lowell Gilmore
Dr. William Forrest
Philip Van Zandt
Anton Radchek
Charles Evans
Dr. Homer Allen
Frank Ferguson
Carl Bemish
Reed Hadley
Narrator (voice)
Ray Teal
Police Sergeant
William Tannen
FBI Chemist
Gale Storm
Voice on Tape Recorder
Arthur Space
Mr. North
Tamara Shayne
Mrs. Ecko, the Landlady
Keith Richards
FBI Agent Miller
Grandon Rhodes
Adolph Mizner
Steve Pendleton
Police Detective Gaines
Howard Negley
Feodore
Jimmy Lloyd
FBI Agent Alison
Myron Healey
FBI Agent Thompson
John Hamilton
G.W. Hunter
Paul Bryar
Fred Coby
Bert Davidson
Marten Lamont
Lee Phelps
Suzanne Ridgway
Arthur Tovey
Crane Whitley
Gordon Douglas
Director
George Bruce
Screenplay
Bertram Millhauser
Story
Grant Whytock
Producer
George Robinson
Director of Photography
Joseph Small
Unit Manager
Rudolph Sternad
Art Direction
Edward Colman
Camera Operator
Dorothy B. Cormack
Script Supervisor
Edward P. Lambert
Wardrobe Supervisor
John R. Carter
Sound
Edward Small
Producer
Norbert A. Myles
Makeup Artist
James E. Newcom
Editor
Howard Bristol
Set Decoration
Ken Lobben
Still Photographer
Margaret Martin
Hairstylist
Paul Sawtell
Original Music Composer
William Dalton
Grip
Ridgeway Callow
Assistant Director