Don Terry
Larry Kent
Acting
Gwen Gaze
Toni Morrell
Acting
Walter Miller
Carter 'The Shark' Collins
Acting
George Rosener
Capt. Samuel Cuttle
Acting
Grant Withers
Roderick Gridley
Acting
Hobart Bosworth
Dr. X
Acting
Sandra Karina
Nurse Zanya
Acting
P.J. Kelly
Prof. Gault
Acting
Yakima Canutt
Dreer (Mole-Men Leader)
Acting
William Farnum
George Brennan Westmore (Editor)
Acting
Joe Caits
Saltwater Jerry [Chs.1,4-7,13-15]
Acting
Colin Campbell
Hawkins (the Butler) [Chs. 1-3]
Acting
Dave O'Brien
Det. Jameson [Chs. 4-7]
Acting
William Royle
Paul Thorndyke [Ch.1]
Acting
Warner Richmond
Capt. Tom Stanton, alias Capt. Tom Faxton [Ch.1]
Acting