Tony Wendice learns that his wife, Margot had an affair but even though it's over, he decided to kill her but chose to bide his time. He waited until Mark Halliday, his wife's boyfriend, returned to town. He then placed his plan in order. He summons a hit man and convinces him to agree to kill his wife Margot and her lover. He has laid out what appears to be perfect plan. Or is the perfect trap?