The narrator starts his opinionated view of the story. He tries to convince the audience he isn't mad for killing the man. And blaimed it all on all the old man's eye.
The narrator lived in the same building as the old gentleman. The narrator spoke to him with kindness for the week before he planned to murder him. The insane man wanted none of the old man's riches. Just for his eye to be gone.
The mad man watched the old man sleep every night that week. Being as quiet and unknown as he could. The last night he went in as normal with his lantern. Then glazed upon the eye that freaked him out.
Tick ... Tick ...
The climax of the story is when the narrator went into the old man's room while he was asleep, and murdered him. The old man left out one scream than died.
The next morning the old man was dead. But the neighbors had heard the one scream and called the police. The narrator came up with a story and successfully fooled the policemen. Until they decided to stay then he felt guilty.
The story comes to an end when the narrator tells the police he committed a murder of the old man. The old man was dead under the floor boards, telling the police that the old man's heart beat is driving him mad.