"Lamb to the Slaughter" is a short story written for adults by Roald Dahl.
Mary Maloney, a pregnant young woman, waits for her husband Patrick to return home from his job as a detective for the local police. When he returns, Mary notices that he is strangely aloof and assumes that he has had trouble at work. After blatantly ignoring her, Patrick finally confesses his intent to leave her and give her the money for living.
In shock at the news, and seemingly in a trance, Mary gets whatever she gets to her hand first from the refrigerator to cook for their dinner. Then Mary gets told to stop the routine and not make him dinner, and she snaps, bludgeoning Patrick in the back of the head with the frozen lamb leg. After pacing the room, Mary realises that she must conceal her crime. She prepares the leg of lamb and places it in the oven. Then, after practising a cheerful routine, she heads out to the grocery shop to buy some vegetables for her roast. When she gets back, she enters the room where she killed her husband and calls the police.
When the police arrive, they question Mary and survey the scene. The police then search the house and surrounding area for the murder weapon. After a fruitless search, the police realise that no one has turned off the oven. Mary offers all the policemen the cooked leg, asking them to accept her hospitality. As the Policeman eat the meat, they discuss the location of the murder weapon, assuming it is right under their noses. Mary overhears this in the other room and giggles to herself at the irony.