At the very beginning of this story the narrator that is also the antagonist tells use that he is not, but just nervous and diseased. However he then tells us that he can tell the story calmly. This then tells that the narrator is unreliable since he has an internal conflict.
During the first part of the rising action the narrator tries to prove his sanity by describing how carefully he planned the Old Man's murder. During this the narrator is kind to the Old Man for the entire week. The narrator creates suspense by sneaking into the Old Man's chamber at 12 every night, opening a lantern and pointing it directly at his "vulture eye" to see if it was open. Every morning the narrator asks the Old Man how he slept. He did this to find out if the Old Man suspecting anything.
On the eight night the narrator wakes the Old Man and decides to keep going into the room. While the Old Man is awake sitting in bed, the narrator and the Old Man have a "standoff." After the Old Man goes back to bed the narrator points the lantern into his eye, and finds that his eye is wide open. He then starts to show examples of foreshadowing and personification when he says that "Death is stalking" the Old Man. Then the Old Man starts to hear a low dull quick sound. He believes that this is the sound of the Old Man's heartbeat. And as it gets louder and louder, and he starts to believe that the the sound of the heartbeat will be heard be a neighbor. Then as the reader we find that the heartbeat symbolizes the narrators anxiety.
On the eighth night while the narrator watches the Old Man sleep, he sees the Old Man's eye open and then he starts to hear a low dull quick sound. Then the narrator starts to believe that the sound is the Old Man's heartbeat and then he thinks that the sound will be heard be the neighbors, in an effort for the neighbors to hear the sound, he screams and throws a mattress over the Old Man and suffocates him/.
The narrator dismembers the Old Man's body in the bathtub and washes the blood out with water so that no evidence could be found. Then the narrator hides the body under the floor boards so it couldn't be found. After this the police arrive because the neighbors called when they heard a shriek. The narrator invites the police to search the home. After they finish the search, the narrator invites them to sit in the Old Man's chamber.
As they are sitting and talking, the Old Man starts to hear the "Old Man's heartbeat," this causes him to become crazy and in doing this the sound gets louder and louder symbolizing the narrator's anxiety. The narrator then becomes so overwhelmed with guilt that he confesses to his murder.