Mr. Rogan
Dr. Marko
Lord Warrick
Mr. Brigstock
British Secretary
Frederick Malone
Chief Inspector W.R. Allison
Sir Robert Bentley
Leuwen Grayle
Charles Seagrave
Giles Conover
Judge Brisson
Major Loring (uncredited)
Businessman (uncredited)
Sir Frederick Fleet
Weatherby (uncredited)
Colonel Fitzhume (uncredited)
Col. Herman Fournier
Paul Panois
Kilpatrick
James V. Thorne
Floyd Kirsten
Dr. Leonard V. Meecham
German Agent on Radio (voice) (uncredited)
Portmaster
Dr. Kurt Immelman
Major Cunningham
Dr. Wilton
Professor Langer
Dr. Lockberg
Doctor (uncredited)
Lord Keith
Tom Armitage
Roger Smythe
Lieut. Strope
Dr. Rankin
Deacon Arnold Foster
Sir Malcolm Drake (uncredited)
Homer
Mr. Charles Pryor
Attorney General (uncredited)
King Henry VI
Sir John Gresham
Horace Granville
Lockwood
Lord Wickham
Cardinal Richelieu
Benjamin Disraeli
Fred Thomas
Ebenezer Balfour
The Sparkler
James Stratton
Corey
Director
King Louis XIII
Garry Ames
Adaptation
Director
Feize
Harley Travers
Captain Auguste Lutte
Wriothesley
Capt. Ronald Dancy, DSO
Writer
Harry Tresham
Dialogue
Ambatriadi
Claude Holford
Director
Gordon Moore
Theatre Play
Script
Director
Gordon Druce
Raymond Carteret
Guy Merrow
Adolf Sperber
Sir Hugo Boycott
Director
Writer
Capt. Gardner
Mr. Borwick
Armand de Marny
Hon Gerald Pillick
Rollo Stevens
Director
Sir James Daring
Sir Neville Moreton
Producer
Godfrey Norton