There was an old man and his son who went insane every time he saw that eye. The son never believed he was insane because he was so precise with everything he did. "He had the eye of a vulture-a pale blue eye, with a film over it."
The son would go into his room with a lantern and watch him while he was asleep. He was going to kill the man. "I had made up my mind to take the life of the old man." He had succeeded.
Once the son had killed the old man, police came because they had heard a shriek from the old man. Everything was going well until the son freaked out, "Villians! I admit the dead! Tear up the planks! Here, here!"