On screen
Cast
19 credited performers
John Baragrey
Dr. Henry Spensser
Mala Powers
Anne Spensser
Otto Kruger
Dr. William Spensser
Robert Hutton
Dr. John Robert Carrington
Ross Martin
Dr. Jeremy 'Jerry' Spensser
Artwork unavailable
Ed Wolff
The Colossus
Charles Herbert
Billy Spensser
Artwork unavailable
Dick Nelson
Charles - Chauffeur-Butler
Artwork unavailable
Roy Engel
Police Inspector
Charles Sherlock
Airline Pilot
George Douglas
Character not listed
Artwork unavailable
Sam Harris
Character not listed
Artwork unavailable
Larry Kerr
Character not listed
Harold Miller
Character not listed
Artwork unavailable
Foster H. Phinney
Character not listed
Artwork unavailable
Max Power
Character not listed
Jack Richardson
Character not listed
Artwork unavailable
Court Shepard
Character not listed
Artwork unavailable
Bert Stevens
Character not listed