In the year 1929, grisly and mysterious murders of men, women and children have been occurring at night all around the streets of London. The corpses are dismembered, and the police have no leads, despite decucing that the killer must be a professional.
Meanwhile, Mary has hit a wall in her marriage. She is constantly horny, but her husband is always too busy; having to run off for "important business". Finally, with the encouragement of her friend Liz, the wife decides it's time to start having a secret affair, and her first choice is Nat, the local butcher.
Prior to this, Mary was always amazed at how the man could sell high quality meat at such low prices. The affair is a success, though, one day - several visits later - the adultress makes a surprising discovery. Making her way into the back room of the butcher shop, she finds Nat preparing meat from the corpse of a recently murdered woman.Panicked, Nat tries to form a believable excuse, but fails. Mary immediately connects the dots and realizes that he is the one that has been killing random people in London. A brilliant idea then comes to her. She decides to blackmail him; stating that the only way she won't go directly to the authorities will be if he also murders her husband in this same fashion, to help ease the pressure of their affair. Nat repeatedly insists that there is something important that he needs to tell her, but the woman will hear nothing of it and doubles down on her threat.
Mary brings Alex to the agreed location one evening, and then flees, all while laughing about how he is going to die. She proceeds to find a place to hide, but becomes increasingly concerned with how long it is taking Nat to finish the job. At long last, she hears footsteps, but then is startled to find both men still alive and grinning at her. It is here that Nat reveals that Alex has been his partner in crime all along, and that he would much rather lose a dangerous lover than a trusted partner.
The story ends with Mary becoming the latest victim to be butchered and sold at the meat shop.