District Attorney Holden and his special investigator Betty Higgins are trying to convict brothers Joe and Lou Manson, silk-racket hoods, after they are indicted for murder.

Muriel Rossi (Mary Brian), the sister of a racketeer, Al Rossi (Harry Woods), falls in love with Bob Martel (Bruce Cabot), the son of a police detective, Joe Martel (Grant Mitchell). Their love affair causes bot families problems when Bob is framed, but saved as a result of his father's access to police department films.

Larry Brewster, partner in the music publishing firm of Brewster and Crow, returns from a trip to find that his partner, J.C. Crow has hired Pat O'Rourke as a song plugger.

The quiet life style of Ruth Heck and her brother Lem, who belong to a religious sect called the Seekers, is disrupted when a judge imprisons Lem for a crime he did not commit.

The Isle of Lost Men is one of those lawless tropical island colonies so beloved of adventure-story writers.