The two lead characters in the story are Mary and Patrick Maloney, a married couple who are not very high up the social ladder since they are a single income family with Patrick being the breadwinner and Mary a housewife. They probably live in a middle class neighbourhood since, Patrick works for the Metropolitan police, he is entitled to a number of social benefits such as subsidised accommodation, medical benefits and so forth.
The story's primary focus is Mary. Dahl's physical description of her in her pregnant state with the focus on her mouth and her eyes, accentuates how innocent and harmless she appears. It is the type of mouth one would expect to never utter a vindictive or disgusting word, and eyes which convey innocence and trust, like those of a young child:
Her mouth and her eyes, with their new calm look, seemed larger and darker than before.
There is, however, a slight hint of some malevolence in the description of her eyes as being 'darker than before.' This, up to now, suppressed element of her nature, later shockingly comes to the fore when she murders Patrick, creates an alibi, has the investigators eat the evidence, and then giggles about it.
Mary is clearly a devoted, loving wife, who literally spends more than a fair portion of her day anticipating and preparing for her husband's arrival from work. She obviously dotes on him and has adopted a servile attitude. There is no mention of her having friends or family in the story, so her world naturally revolves around Patrick. He seems to provide meaning to her existence so she most probably is obsessive about him. It is clear that Mary lives quite a mundane life and she has developed an almost monotonous routine in preparing for her husband's daily arrival home. The author makes this quite clear:
When the clock said ten minutes to five, she began to listen, and a few moments later, punctually as always, she heard the car tires on the stones outside, the car door closing, footsteps passing the window, the key turning in the lock.
For her, this was always a wonderful time of day.
it is pertinently clear that she admired Patrick and had great affection for him and she at pains to ensure that he is satisfied, as Dahl illustrates:
... she was satisfied to sit quietly, enjoying his company after the long hours alone in the house. She loved the warmth that came out of him when they were alone together. She loved the shape of his mouth, and she especially liked the way he didn't complain about being tired.
Patrick Maloney's insensitive, abrupt and brusque manner towards Mary's kindness immediately makes him an unlikable character. He is a policeman stationed at the local office and he is clearly not in an affable mood. Mary intimates that he is dissatisfied with his current position when she comments:
"I think it's a shame, ... that when someone's been a policeman as long as you have, he still has to walk around all day long."
Patrick probably sought some kind of promotion which he hasn't received and he has to remain on the beat - a mind-numbing and frustrating position to be in. He is exhausted at the end of the day, for he has had to walk the same area he patrols. He has most probably become exasperated with this routine and the routine at home that he has gone to seek, and found, some excitement.
When Patrick tells Mary about his decision to leave, one assumes that he might have become involved in an extra-marital affair. Mary, like his job, has become too routine, too dull and he wanted out. His offhanded and uncaring manner informs of a cold and heartless individual.
"And I know it's a tough time to be telling you this, but there simply wasn't any other way. Of course, I'll give you money and see that you're taken care of. But there really shouldn't be any problem. I hope not, in any case. It wouldn't be very good for my job."
Patrick clearly cares more about his mundane job than he does about his wife and unborn child. This makes the reader feel that he deserves his come-uppance when Mary retaliates (probably in a moment of temporary insanity) and kills him.