Bruce Edwards
Steve Colt
Virginia Lee
Joyce Winters (as Virginia Lindley)
                                    Carol Forman
Sombra, The Black Widow
                                    Anthony Warde
Nick Ward
                                    Ramsay Ames
Ruth Dayton
                                    I. Stanford Jolley
Dr. Z.V. Jaffa
Dave Anderson
Porter-Spy
                                    Theodore Gottlieb
Hitomu
                                    Virginia Carroll
Dr. Ann Curry
                                    Gene Roth
John M. Walker
                                    Sam Flint
Prof. Henry Weston
                                    LeRoy Mason
Dr. Godfrey
                                    Forrest Taylor
Bradley
                                    Ernie Adams
Blinky
                                    Keith Richards
Michael Burns
                                    George Chesebro
J. Carter
                                    Frank Lackteen
A. Kabob
                                    Carey Loftin
Spike
Ted Mapes
Slade
                                    Jack O'Shea
Finnegan
Gil Perkins
Burke
                                    John Phillips
District Attorney Mark
                                    Stanley Price
Filmore Hagen
                                    Larry Steers
Dr. Harcourt
Ken Terrell
Mendoza
The Black Widow
Released