Published in 1843, "The Black Cat" is a short story that explores murder, madness and the supernatural. In the story, the narrator is a man who is awaiting his death sentence for killing his wife. While waiting, he relays the story of how he arrived in his current situation. The man was a compassionate and kind-hearted person who loved animals along with his wife. Their shared love of pets resulted inthe procurrment of a variety of animals, including a black cat called Pluto. The narrator loves and adores Pluto despite his wife's musing that black cats are witches in disguise. His love for Pluto and overall demeanor takes a turn for the worse because of alcoholism. He becomes irritated easily, hits his wife occasionally and begins to hate the cat. One night in his drunkenness, the narrator cuts Pluto's eye out because Pluto scratched him.

The fury of a demon instantly possessed me. I knew myself no longer. .... I took from my waistcoat-pocket a pen-knife, opened it, grasped the poor beast by the throat, and deliberately cut one of its eyes from the socket! 

The narrator regrets his decision but is soon again consumed by anger because Pluto flees from him due to the trauma he endured.

One morning, in cool blood, I slipped a noose about its neck and hung it to the limb of a tree; -- hung it with the tears streaming from my eyes, and with the bitterest remorse at my heart; -- hung it because I knew that it had loved me, and because I felt it had given me no reason of offence; -- hung it because I knew that in so doing I was committing a sin...

He kills Pluto and shortly afterwards, the narrator's house burns down. When he comes back, the narrator discovers a huge scorched outline of the cat's body on the wall above his bed. The narrator soon finds another cat who resembles Pluto except for a white patch on its breast. The cat follows the narrator everywhere and the white patch begins to turn into an outline of the gallows, an action and occurrence that begins to irritate and scare the narrator. While walking down into the old house's cellar, the cat trips up the narrator. In a fury, the narrator tries to ax the cat but is stopped by his wife. As a result, the narrator axes is wife and hides her in a false wall in the cellar. He resumes to try and kill the cat but can't find it and soon stops looking for it. 

A few days go by and the police begin to search for the narrator's wife. They can't find any trace of her. When they begin to leave the premises, the narrator's smugness gets the better of him and he starts to talk about the sturdiness of the walls of the house.

The glee at my heart was too strong to be restrained. I burned to say if but one word, by way of triumph, and to render doubly sure their assurance of my guiltlessness.

As he discusses how well structure the house is, he knocks against the very portion of wall where he buried his wife. In response, a loud scream is heard within and the police officers begin to tug at the wall and quickly reveals the wife's decaying body. On top of the dead wife's head is the black cat, alive.  

The corpse, already greatly decayed and clotted with gore, stood erect before the eyes of the spectators. Upon its head, with red extended mouth and solitary eye of fire, sat the hideous beast whose craft had seduced me into murder, and whose informing voice had consigned me to the hangman. I had walled the monster up within the tomb!

The narrator is one of Poe's monsters because of the murders and mutilation he inflicts on the innocent. However, the second black cat could also be considered a monster; that affirmation comes from the narrator's perception of monstrosity that the cat evokes with his presence and the superstition that surrounds him. Alcoholism is the agent that ignites the change in the narrator's demeanor and fuels his rage but scorch-marked Pluto and the changed image on the second cat's breast make the narrator believe in monsters. He saw the second cat as a monster and was more so convinced when the scream of the cat led police to the body of his wife. 

It was now the representation of an object that I shudder to name -- and for this, above all, I loathed, and dreaded, and would have rid myself of the monster had I dared...