Ex-convict Casey Martin (Lovejoy) is caught heisting a truck shipment. In exchange for immunity from prosecution, he agrees to work undercover to nail mobster Dutch Becker (Tucker). Torn between the two men is Martins's ex-girlfriend and gangster's moll Gladys Baker (Castle). When she casts her lot with Martin, she gets murdered by Becker's sadistic chief henchmen Lou Terpe (Carey). In the end Martin brings down the gang and is allowed to go on his way.