The inventor of a new top-of-the-line burglar alarm system is kidnapped by a gang in order to get him to help them commit robberies.
| Actor | Role |
|---|---|
 Boris KarloffDavid Mallory | David Mallory |
 Warren HullJim Travers | Jim Travers |
 Jean RogersJoan Mallory | Joan Mallory |
 Alan BaxterJohn Baron aka The Kid | John Baron aka The Kid |
 Hobart CavanaughPetty Louie | Petty Louie |
 Samuel S. HindsSteven Ranger | Steven Ranger |
 David OliverMike Callahan | Mike Callahan |
 Ward BondFingers | Fingers |
 Frank ReicherCarl - gang engineer | Carl - gang engineer |
 Edwin MaxwellLawyer Kruger | Lawyer Kruger |
 George ClevelandSam Adams - Company Engineer (uncredited) | Sam Adams - Company Engineer (uncredited) |
| RRuth FallowsWaitress (uncredited) | Waitress (uncredited) |
 George HumbertMr. Spinelli (uncredited) | Mr. Spinelli (uncredited) |
| NNina CampanaMrs. Spinelli (uncredited) | Mrs. Spinelli (uncredited) |
 Charles Cahill WilsonPolice Capt. Wallace (uncredited) | Police Capt. Wallace (uncredited) |
 Chuck HamiltonPoliceman (uncredited) | Policeman (uncredited) |