The story is set in a house that is shared by the old man and the narrator. The mood at the moment is very subtle and calm with the narrator being polite for a reason, and doing his work. While the old man is describing the things that need to be done.
Over a period of about 8 days the narrator has been stalking the old man while he sleeps. He is plotting to murder the old man for an odd reason. He is very disturbed by the old mans fake eye or as the narrator would say, "vulture eye." Every night for those 7 or 8 days he has been very caution to sneaking in his room and just standing there observing him with a dully lit lantern.
On the eighth night the narrator finally makes the choice to actually kill the man. The narrator acts politer than usual throughout the day. That night he is way more cautious and careful than he has been the previous nights. When he opens the door and walks into the room a couple of steps. The narrator accidentally makes a noise causing the old man to sit up in his bed. They both wait one hour until the narrator makes the move and actually kills the old man.
After his own deed is done he plants the dead body in the house under a floorboard. A few hours later the police arrive and are questioning the noise that was heard by someone in the middle of the night. The narrator covers his story up by saying it was him who made a scream because he had a bad dream. The police officers actually believe him but still stay to investigate. They ask where the old man is and the narrator explains yet another lie that he has traveled out of town.
The narrator pulls out chairs for everyone and they all sit down and just talk for a while. Something starts to occur though. The narrator believes he is hearing a noise very much like a heartbeat. His insanity is starting to get to him, but he doesn't know that is what is happening. So he keeps hearing something getting louder and louder. Soon, he realizes that the officers aren't hearing it too, but they start to act like they do. Which causes the narrator to commit his crime.