Diretor/a
Gordon Douglas
DIRETOR/A
Elenco (na ordem dos créditos)
Louis Hayward
Philip 'Scotty' Grayson
Dennis O'Keefe
Daniel F. O'Hara
Louise Allbritton
Dr. 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)
Paul Bryar
Ivan (uncredited)
Fred Coby
Fred - FBI Chemist (uncredited)
Bert Davidson
Potter - FBI Agent (uncredited)
John Hamilton
G.W. Hunter (uncredited)
Myron Healey
Thompson - FBI Agent (uncredited)
Marten Lamont
FBI Chemist (uncredited)
Jimmy Lloyd
Alison - FBI Agent (uncredited)
Howard Negley
Feodore (uncredited)
Steve Pendleton
Gaines - Police Detective (uncredited)
Lee Phelps
Cop (uncredited)
Grandon Rhodes
Adolph Mizner (uncredited)
Keith Richards
Miller - FBI Agent (uncredited)
Suzanne Ridgway
Extra at Murder Scene (uncredited)
Tamara Shayne
Mrs. Ecko - Landlady (uncredited)
Arthur Space
Mr. North (uncredited)
Gale Storm
Mrs. Green - Voice on Tape Recorder (uncredited) (voice)
William Tannen
Ray Teal
Police Sergeant (uncredited)
Arthur Tovey
Plant Worker (uncredited)
Crane Whitley
Curly (uncredited)