John Hart
Jack Armstrong
Rosemary La Planche
Betty Fairfield
Claire James
Princess Alura [Chs. 3-6, 9-11, 15]
Joe Brown Jr.
Billy Fairfield (as Joe Brown)
Pierre Watkin
Uncle Jim Fairfield
Wheeler Oakman
Prof. Hobart Zorn
Jack Ingram
Henchman Blair
Eddie Parker
Henchman Slade
Hugh Prosser
Vic Hardy