A zero ending is one that does not perfectly tie up the threads of a story. It may not even feel like an ending: in some cases, the writer may seem to have stopped in the middle of a thought or idea. The abrupt ending of the story leaves many questions unanswered, such as how the narrator has changed, whether his relationship with his wife will change, or how his opinion of Robert has changed. But the answers to these questions are not what the story is about. “Cathedral” is about the change in a man's understanding of himself and the world, and the narrator ends the story exactly as that change flickers in his mind. The narrator has not become a new person or attain any enlightenment that could change his soul. In fact, the narrator's final words, "That's really something," reveal him to be the same dry, inarticulate man he's always been.