Mobs, Inc. plot
Police captain John Braddock of the Los Angeles "Racket Squad" trains a group of prospective police officers. He tells them about three precarious and dangerous cases that demonstrate the skills of criminals. The first case concerns tracking down a dancer. Together with a major criminal, she is thwarted in order to commit a robbery. The second case is about a swindler who wants to defraud a book publisher during a transatlantic journey. The third case concerns the thwarting of a scammer's plans to set up a so-called nationally operating syndicate.