Howard L. Edwards, Railroad manager
Tully Marshall
Stevens, Railroad attorney
Conway Tearle
Gloria Stratton, aka Gloria Martin
Shirley Grey
Frank Stratton, Gloria's father
Edmund Breese
Walter Gray, Airline manager
Lloyd Whitlock
Carlson, Plainville station agent (as Alan Bridge)
Al Bridge
Tom Jordan, Railroad engineer (as Mathew Betz)
Matthew Betz
Det. Matthews (as Joseph Girard)
Joseph W. Girard
Det. Hemingway, Matthews, assistant (as James Burtis)
James P. Burtis
Henchman Barney, Machine gunner (as Ernie S. Adams)
Ernie Adams
Henchman Mike
Charles King
Jim Baker, Railroad engineer [Chs. 1, 5]
J. Farrell MacDonald
Henchman Sandy, The "Wrecker's" pilot
Al Ferguson
Henchman Jim
Glenn Strange
