The "caretaker" is in jail telling his cell mate the story about what had happened and why he is in jail.
The caretaker was determined to take the life of the old man after he thought that the eye was evil. He wanted to rid himself of the eve forever.
The caretaker stalks the old man in his sleep for a few nights, on the eighth night, he was peeking in when the old man heard the door he sprung up.
This time, the caretaker saw the eye open and decided to attack, he went towards him, dragged him to the floor and threw the bed over him, to have suffocated him. The old man was now dead. He chopped him up quietly and his the rest of the corpse under the floor boards.
The police next show up at the old mans house, they said that the neighbors had heard a shriek and were concerned, the caretaker lets them in and lets them look around the house. He puts chairs for the police where he had disposed of the body, under the floor boards.
The police walk into what was the old man's room. The caretaker is casually talking to them until suddenly he starts to hear a sound. The sound in his head starts to get louder and louder until he cant take it anymore. He yells out, confessing the crime of the old man. The sound, he thought, was the beating of the old mans heart.