Two newly-appointed postal inspectors, Frank Marshall and 'Slim" Hewitt, set out to track down the sender of a time-bomb to a U. S. Senator and, during their investigation, run across a hooded organization that is terrorizing an American city. They also meet Don Foster, who is loud in his condemnation of the terrorists, and his sister, Nancy, who fears for her brother's life.
Bruce Cabot
Frank MarshallCrawford Weaver
Slim HewittWard Bond
Don FosterJohn Tyrrell
Feeney (as John Tyrell)Nick Copeland
Lefty (as Nicholas Copeland)Arthur Loft
GardnerCharles C. Wilson
Colonel McCollum (as Charles Wilson)John Hamilton
Cummings