Dr. Melcher aka Monsieur Colomb / Cell Prisoner
Alice Saunders
Dr. Bill Saunders
Dick Martin
Amos Hanlin
Ryder (as Edward Piel Sr.)
Phillip Wallace
John Van Dyke
FBI Chief Colton
Kearney
FBI Agent
Stevens
The Dragon (as Stanford Jolley)
Policeman (uncredited)
Hotel Clerk (uncredited)
The Cabbie (uncredited)
Industrialist (uncredited)
Girl at Party (uncredited)