Former tennis pro Tony Wendice (Ray Milland) hatches a cunning plot to get rid of his socialite wife, Margot (Grace Kelly), when he discovers that she has been unfaithful. Wendice blackmails a corrupt former schoolmate into murdering Margot, but the fellow bungles the job, and Margot, having killed her would-be assailant in self-defence, then finds herself under suspicion of premeditated murder! Director Alfred Hitchcock shot this adaptation of Frederick Knott's successful stage play in 3-D, and went on to employ Grace Kelly again on 'Rear Window' and 'To Catch a Thief'.