“Listen,” he said. “I’ve got something to tell you.”
“I’ll get the supper”
"So I've killed him"
"The drop of the head as she bent over her sewing was curiously tranquil." This scene of the story would represent the 1950's side of her character as fitting in to the stereotype of women in this time period.
"And he told her. It didn’t take long, four or five minutes at most, and she stayed very still through it all, watching him with a kind of dazed horror as he went further and further away from her with each word." This is the point that Mary Maloney's character starts to change from the 1950's stereotype to a entirely different personality.
“I’ll get the supper,” she managed to whisper, and this time he didn’t stop her. In this point of the story all that she is she really does not know what she is doing and this sort of "daze" leads her to murder Patrick.
"She wants us to finish it. She said so. Be doing her a favor."
At this point in the story she is out of her "daze" that she is in when she kills him. She is now asking herself how she is not going to get caught.
She is thinking of how to get a way with the perfect murder when these police officers are searching the house. She already has an advantage because they would never think a woman would ever commit such a crime.
"She told us to finish it". The story ends with Mary laughing as she gets away with the perfect murder.