Mary Maloney was just getting the house ready, waiting for her husband to come home. When he arrived she greeted him eagerly, as they made their way to the other room for a drink.
Mary and her husband were having their drink and talking. But really she was the one talking not him. She offered to make him dinner but he told her he wasn't hungry and that she needed to sit down because he had to tell her something, this scared her. We aren't told what he says but I am confident he says he has to leave her. She's angry and shocked and says she needs to make dinner.
He suddenly became very angry and told her again that he didn't want dinner. He said he was going out to eat. Rage and anger welled up inside of her she grabs a leg of lamb and hits him in the end. She looks down at her dead husband in shock. She suddenly realised she needed to cover this murder up. First thing she did was put the lamb in the oven and leave to go to the market.
The grocer Sam greets Mrs Maloney very eagarly and is happy to see her. She acts very normal and says she is buying some vegetables for her husband's dinner. She buys some peas and potatoes, but when he offers her a leg of lamb she says no because she has one at home. She also buys some cheese cake for desert and then leaves.
After she's unpacked everything she calls the police and pretends she is very scared and came home to her husband dead. The police come at once and scout the scene of the crime. They say that he was hit with some sort of large metal and his skull was crushed. Mary is very persuasive and convinces them to have a drink hoping to get them drunk. Then remind her she has a lamb in the oven.
Se then fetches the lamb and convinces them to stay for dinner. They are all talking normally and talking about the whole situation. She tells them to go ahead and eat the whole thing because she is 'very upset and couldn't eat anything right now'. Little do they know they just ate the murder weapon.