Tom Brown

'Smilin' Jack' Martin

Marjorie Lord

Janet Thompson

Rose Hobart

Trudy Muller, aka Fraulein von Teufel

Keye Luke

Captain Wing

Edgar Barrier

Tommy Thompson

Cyril Delevanti

Mah Ling / Han Po, his double

Philip Ahn

Wu Tan

Turhan Bey

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

Sidney Toler

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

Jay Novello

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

Rico De Montez

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

Nigel De Brulier

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

Edward Keane

Hon. George Hill [Chs. 8-12]

William Forrest

Secretary of Internal Affairs [Chs. 8-12]

Jack Gardner

Captain Yoshido [Chs. 1-3]

Terry Grey

Shuma, pilot [Chs. 1-3]

Stanley Blystone

Capt. Hardigan [Chs. 5-6]

Herbert Heyes

Sir Cedric [Chs. 5-7]

James Craven

Commissioner Robert George Hardy [Chs. 5-7]

Alex Havier

Sanson, phoney waiter [Chs. 6-7]

Paul Bryar

Herr Bauer [Chs. 6-7]

Norma Drury

Frau Bauer [Chs. 6-7]

Grace Cunard

Second German Woman Spy [Chs. 6-7]

David Hoffman

John O. Blenker [Chs. 9-11]

Edward Peil Sr.

Freighter Captain [Chs. 7-8]

Wheeler Oakman

Freighter Mate [Chs. 7-8]

Frederick Giermann

Schlesser, device expert [Chs. 10-11]

Bert Freeman

Shimoto, device operator [Chs. 10-11]

Harry Strang

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