Defense attorney Dwight Bradley Masen (Walter Pidgeon) is successful in seeking the acquittal of a young man, Rudi Walchek (Keefe Brasselle), accused of knifing to death the 19-year-old son of a local locksmith, but when Rudi lets a comment slip after the trial, Masen realizes he has defended a guilty man. Masen discovers that Rudi is also a member of a syndicate extorting money from the scared merchants in the locksmith's neighborhood. After unearthing new evidence, Masen tries to convince the D.A. (Barry Sullivan (actor)) to retry the case, but the latter refuses on grounds of double jeopardy.