The first paragraph of Edgar Allan's Poe's short story, The Tell-Tale Heart, sets the tone of the macabre horror that continues throughout the tale. The narrator tells us that he is not mad, but that he hears "all things in the heavens and the earth" as well as "many things in hell." In the second paragraph, the narrator continues, admitting that he "loved the old man," but that he plans to murder him anyway. The following paragraphs tell in detail how thoroughly the narrator planned his killing, looking in on the old man after he was asleep each night. The narrator's later acts describing the fear in the old man when he awakes to a noise; the murder itself; and the resulting dismemberment of the body build the horror until the climactic ending when he rips up the planks of the floor to reveal "the beating of his hideous heart."
Edgar Allen Poe supports horror by the repetition of words. The narrator repeats certain words several time as if to pull the reader into his internal anxiety.
"TRUE! nervous, very, very dreadfully nervous."
The type of narrative Poe used indicates to the reader the level of insanity of the speaker. Scary stories often involve a person with a deranged mind. Poe's narrator tries to convince us that he is not crazy while verbally indicating that he is crazy.
The murder scene in the story is indicative of horror. The narrator also builds fear and tension in the story by telling how the man must have felt when the narrator sneaks into his room.
The descriptive passages about the man's eye create a visual scary effect.
"One of his eyes resembled that of a vulture -- a pale blue eye with a film over it."