Tom Brown

Character: 'Smilin' Jack' Martin

Marjorie Lord

Character: Janet Thompson

Rose Hobart

Character: Trudy Muller, aka Fraulein von Teufel

Keye Luke

Character: Captain Wing

Edgar Barrier

Character: Tommy Thompson

Cyril Delevanti

Character: Mah Ling / Han Po, his double

Philip Ahn

Character: Wu Tan

Turhan Bey

Character: Kageyama [Chs. 1-5, 12-13]

Sidney Toler

Character: General Kai Ling [Chs. 1-5, 13]

Jay Novello

Character: Kushimi, infiltrator [Chs. 1-3, 12-13]

Rico De Montez

Character: Henchman Hito [Chs 1, 4, 12-13]

Nigel De Brulier

Character: The Lo-San [Chs. 2-3, 12-13]

Edward Keane

Character: Hon. George Hill [Chs. 8-12]

William Forrest

Character: Secretary of Internal Affairs [Chs. 8-12]

Jack Gardner

Character: Captain Yoshido [Chs. 1-3]

Terry Grey

Character: Shuma, pilot [Chs. 1-3]

Stanley Blystone

Character: Capt. Hardigan [Chs. 5-6]

Herbert Heyes

Character: Sir Cedric [Chs. 5-7]

James Craven

Character: Commissioner Robert George Hardy [Chs. 5-7]

Alex Havier

Character: Sanson, phoney waiter [Chs. 6-7]

Paul Bryar

Character: Herr Bauer [Chs. 6-7]

Norma Drury

Character: Frau Bauer [Chs. 6-7]

Grace Cunard

Character: Second German Woman Spy [Chs. 6-7]

David Hoffman

Character: John O. Blenker [Chs. 9-11]

Edward Peil Sr.

Character: Freighter Captain [Chs. 7-8]

Wheeler Oakman

Character: Freighter Mate [Chs. 7-8]

Frederick Giermann

Character: Schlesser, device expert [Chs. 10-11]

Bert Freeman

Character: Shimoto, device operator [Chs. 10-11]

Harry Strang

Character: Honolulu Detective-in-charge [Chs. 10-12]