The narrator and the wife loved animals and owned a monkey, birds, a dog, a fish, a rabbit, and a cat named Pluto.
The narrator gouged out the cat's eye because he was an alcoholic and abused his animals poorly.
The narrator got angered by the cat because the cat was scared of the man so he kept running away from him. So the narrator hung the cat from a tree.
After feeling guilty about killing the cat, he went to the bar to drink away his problems. He found a new cat that looked exactly like the first cat but with a white splotch on it's chest. The cat was even missing an eye.
When he brought the cat home, the cat wouldn't leave him alone. He finally couldn't take it anymore when the cat made him almost trip going down the stairs. So, he went to kill the cat with an axe. But when the wife went to stop him, the narrator turned around and killed his wife.
Four days after hiding the wife in the wall of the cellar, the cops came. After finding nothing, the narrator tapped on the wall where he hid his wife and he heard a screech coming from inside the wall. The cops took the bricks out of the wall, finding the cat laying on top of the wife's head, with blood dripping from it's mouth.