I grew, day by day, more moody, more irritable, more regardless of the feelings of others. I suffered myself to use intemperate language to my wife. At length, I even offered her personal violence.

These three brief sentences occur toward the beginning of the story right as the narrator introduces his alcoholism. Here the narrator describes the immediate and terrible effect alcohol has on his family. The narrator’s vagueness in the description of his abuse here contrasts sharply with the later, more graphic sections of violence, suggesting potential remorse. This quote also marks one of the few appearances of his wife in the story. She quickly fades to the background as the narrator descends more into his alcoholism, as if the narrator has no ability to notice her in the face of his emotions.

Goaded, by the interference, into a rage more than demoniacal, I withdrew my arm from her grasp and buried the axe in her brain.

The narrator murders his wife after she stops him from murdering the second black cat with the ax. The swift brutality with which the narrator reacts to her preventing him from doing what he wants to do emphasizes how alcohol has eroded his inhibitions and increased his selfishness. This killing is impersonal. He doesn’t speak to his wife or even state that he is mad at her, but rather at her interference, as if she is a mere obstacle.