Having said that his cat, Pluto, was unusually intelligent, the narrator of "The Black Cat" continues:

In speaking of his intelligence, my wife, who at heart was not a little tinctured with superstition, made frequent allusion to the ancient popular notion, which regarded all black cats as witches in disguise.

The narrator thinks that his wife was not quite serious on this point but mentions it in any case, and it has a clear bearing on the events he relates.

As he tells his story, the narrator is under sentence of death. Though the crime for which he is to be executed is the murder of his wife, he also seems to feel that he is being punished for his cruelty to the two cats in the story, particularly the first, Pluto. The narrator gouged out Pluto's eye with his pocketknife in a fit of drunken rage, then, later, killed the cat by hanging him by the neck from a tree in his garden. The fact that he is now due to be executed, probably in a similar manner, might be taken as evidence of Pluto's supernatural power of revenge. However, this event was also foreshadowed the night after he killed Pluto, when his house burned down. Although the burning of the house might, by itself, be regarded as a coincidence, he returns the next day to find "the figure of a gigantic cat" with a rope around its neck on the wall of the ruined house. This seems to confirm his wife's superstition.