- Bela Lugosi
- Victor Poten
- Bruce Bennett
- Martin Andrews
- Joan Barclay
- Joan Whiting
- Luana Walters
- Sonya Rokoff - aka The Dragon Lady [Chs. 1-14]
- Maurice Liu
- Willy Fu
- Charles King
- Grogan - Henchman [Chs. 1-13]
- William Buchanan
- Healy - Henchman
- Forrest Taylor
- Police Capt. Walters [Chs. 1-7, 12-15]
- John Cowell
- White Chinaman [Ch. 1]
- James B. Leong
- Wong [Chs. 5-13]
- Henry T. Tung
- Dr. Wu [Chs. 1-5, 12-15]
- Paul Fung
- Tom Chu [Chs. 1,2]
- George Chan
- Old Luce [Chs. 1,2,7]
- Moy Ming
- Charlie - Wong's Brother [Chs. 10-11]
- Victor Adamson
- Weasel-Looking Henchman [Chs. 1, 4-7]
- Lester Dorr
- Steamship Ticket Clerk [Ch. 7]
- John Elliott
- Ship's Captain [Chs. 8-10]
- Jack Evans
- Henchman
- Harrison Greene
- Mayor Foley [Ch. 1]
- Henry Hall
- Dr. Zander, Psychiatrist [Ch. 12]
- Robert F. Hill
- Pedestrian [Ch. 14]
- Sam Katzman
- Pedestrian [ch. 14]
- Richard Loo
- Loo, Chinese Man on Street [Chs. 5-7]
- Bruce Mitchell
- Riley - Police Officer [Chs. 1, 4, 13]
- Roger Williams
- Newspaper Editor Harrison [Chs. 5, 7, 13, 15]
- Victor Wong
- Bystander [Ch. 2]
- Lee Zahler
- Pedestrian [ch. 14]
