Charles Quigley
Duncan Richards
Linda Stirling
Diana Farnsworth
Clayton Moore
Louis Ashe
I. Stanford Jolley
Dr. Blackton [Ch. 11]
Kenne Duncan
Dr. Chambers [Chs. 1-2, 8]
Forrest Taylor
Prof. Van Wyck
Emmett Vogan
Anderson [Chs. 1-4]
Sam Flint
Maxwell
Joseph Forte
Prof. Parker (as Joe Forte)
Stanley Price
Count Fator [Chs. 11-12]
Wheaton Chambers
Wilson [Ch. 1]
Tom Steele
Henchman Stricker [Chs. 4, 7, 9]
Dale Van Sickel
Henchman Harte [Chs. 6-7]
Rex Lease
Bain
