Everything up to the point where the narrator taps on the wall and the second cat screams--making the reader think it is the spirit of his entombed wife--is the rising action. The tapping on the wall and the immediate circumstances that follow are the climax (point of greatest tension or excitement) of the story.
In "The Black Cat" by Edgar Allen Poe, the rising action begins when the narrator starts drinking and abusing the cat. The situation escalates because he feels remorse but once again drink causes him to abuse the cat and then he hangs it outside. The narrator and his wife get a second cat and here the ultimate downfall of the narrator starts. The narrator begins abusing his wife and is afraid of the new cat.