Johnny Damico (Broderick Crawford), a detective going home in the rain one night, finds himself just a few feet from a shooting on a dark street, where the gunman claims to be a detective from another precinct, flashing a real badge—and then slipping away. Damico discovers that the victim of the shooting was a witness who was to have appeared before a grand jury investigating waterfront crime, and that the same man who shot him also murdered the chief investigator on the case just a few hours earlier (which is where the badge came from).