Laura is preparing a family dinner when her friend, Helen, drops in. While she and Helen are chatting, Laura's husband, Paul, rings to say that he will not be home until the next day. Laura reacts angrily and, due to a mysterious gift, unwittingly places a curse on him. In her disappointment, Laura lets slip to Helen that she has had doubts about Paul's fidelity, and that she is sure that there was a woman in the car with him. Unexpectedly, Paul returns home, badly injured, having been involved in a serious car accident. He refuses to go to hospital so Helen, who is a nurse, treats his injuries. When she has left, Paul tells Laura that her suspicions were right. He was having an affair and he had been leaving with the other woman when the accident occurred. A fight ensues, leaving Laura at Paul's mercy. Helen returns to find Laura unconscious and badly beaten yet unwilling to cancel the evening. Following the arrival of her dinner guests-her brother, Robert, and his wife, Jane-Laura's suspicions as to the identity of the other woman are dispelled and she insists that the subject is not discussed during the meal despite the discovery of traces of blood and the disappearance of a knife. The meal finally over, the evening descends, amid much speculation, into deepening mystery until, eventually, the police arrive and the identity of the other woman is finally revealed.