Dr. Melcher/ Monsieur Colomb

Lugosi Béla

Acting

FBI Agent Richard ‘Dick’ Martin

Clayton Moore

Acting

Alice Saunders

Joan Barclay

Acting

Dr. William Saunders

George Pembroke

Acting

Amos Hanlin

Robert Frazer

Acting

Phillip Wallace

Robert Fiske

Acting

John Van Dyke

Irving Mitchell

Acting

Ryder

Edward Peil Sr.

Acting

FBI Chief Colton

Kenneth Harlan

Acting

Kearney

Max Hoffman Jr.

Acting

Stevens

Joseph Eggenton

Acting

The Dragon

I. Stanford Jolley

Acting

FBI Agent

Frank Melton

Acting