Postal Inspector Al Goddard (Alan Ladd) is assigned to investigate the murder of a fellow officer. The only witness to the crime is Sister Augustine (Phyllis Calvert), who identifies the photograph of one of the assailants. This leads Goddard to a seedy hotel where he learns that the assailant is a member of a gang headed by Earl Boettiger (Paul Stewart), and he soon discovers that the gang is planning a million dollar mail robbery. This classic film noir also features the stars of Dragnet, Jack Webb and Harry Morgan, as Stewart's Henchmen. This was Alan Ladd's final Film Noir and was directed by Lewis Allen (The Uninvited).