Ex-convict Casey Martin (Lovejoy) is caught heisting a truck shipment. After he discovers the depths of alcoholism his sister, Lucille, has fallen to after working for mobster Dutch Becker (Tucker), Casey accepts the deal police have offered him. He goes to work undercover to nail Dutch and his gang; if he survives and is successful, Casey will receive immunity from prosecution.
Gladys Baker (Castle) worked for Dutch for a long time. She has been an associate of Casey's as well and is falling for him. She tells him about her relationship with the mob man and casts her lot with Casey; this gets her murdered by Dutch's sadistic chief henchman Lou Terpe (Carey). In the end Casey brings down the gang and, while he is allowed his freedom, he walks off into a still uncertain future.
