Grace Kelly and Ray Milland star in Alfred Hitchcock's classic thriller adapted from the play by Frederick Knott. Former tennis pro Tony Wendice (Milland) hatches a cunning plot to get rid of his socialite wife, Margot (Kelly), when he discovers that she has been having an affair with author Mark Halliday (Robert Cummings). Wendice blackmails a corrupt former schoolmate into murdering her, but the man bungles the job, and Margot, having killed her would-be assailant in self-defence, then finds herself under suspicion of premeditated murder...