Sweeney! is the first of two big screen outings for tough London cops Detective Inspector Jack Regan (John Thaw) and Detective Sergeant George Carter (Dennis Waterman), the stars of the 1970s TV crime series The Sweeney. Inspector Regan is asked by a criminal contact, Ronnie Brent (Joe Melia), to investigate the death of his young mistress Janice. Supposedly she has committed suicide, but Ronnie is suspicious and doesn't accept the official coroner's verdict. Glamour girl Janice, played unexpectedly by TV OXO mum Lynda Bellingham, was a "social secretary" at an upmarket PR firm run by American businessman Elliott McQueen (Barry Foster). But her duties seemed to be mostly to provide comforts and entertainment for McQueen's clients, including visiting businessmen and politicians. There's always time for a quick smoke: Carter (Dennis Waterman) and Regan (John Thaw)