Poe uses the changes in the narrator to show the idea of surprise in the story. In the beginning, the narrator is a warm, caring preson who loves animals. Due to alcoholism, however, his personality changes. By the end of the story, he is a cruel, cold-blooded murderer. The degradation of his personality is a surprise to the reader.
As the narrator's personality degrades, so does the setting of the story. He first lived in a large, relatively expensive home. But after he killed Pluto, that house burned to the ground. Faced with poverty, the narrator and his wife were forced to move into an older, less-expensive house. The narrator's personality sunk to its lowest point when he was in the house's dark, dank basement. Throughout the story, the setting changed with the narrator.
The suspense from the long exposition and rising action further the idea of surprise. In the exposition, the narrator tells how he loved animals, how he started to abuse them, that he killed Pluto, and all the way up to his meeting the new cat. In the rising action he tells how he feared this new cat and was going to kill it, but instead killed his wife. He buried her in the cellar wall, and he felt he had gotten away with the murder. With these two parts of the story's plot stretched out, the story is more suspenseful.
Poe makes use of several literary elements to create a total effect of surprise and suspense. The narrator does something completely unexpected. The setting changes as the narrator does. And there is a long exposition and rising action which add suspense. As with many of his short stories, Poe gives the reader a sense of surprise in "The Black Cat."