Edgar Allan Poe: The Tell-Tale Heart: The horror of a dead heart - still beating

In this story, Poe does a masterful job of describing the inner thoughts of a man who is obsessed with an old man 'with a filmy pale blue 'vulture-eye'. He knows deep in his soul that that eye is evil and his madness and obsession with it increases each day as he carefully calculates the murder of the old man. Attempting the perfect crime, he dismembers the body in the bathtub and hides it under the floorboards of his room, happy with the result. Until a policeman comes to look into the disappearance of the man and sits directly on top of where the pieces are hidden. Is he imagining things, or does that dead heart still beat?