The story begins with the suspiciously specific denial of the narrator that he is not insane in any way, although he suffers from a certain illness that expands his senses and makes him extremely nervous because of it. The narrator has hearing so perfect that he claims to hear heaven and hell, though it seems to sound like some delusions caused by his mental state. He tells us that he lives in the house with the old man, who is, probably, the owner of the house and another neighbor.
The narrator has nothing against the old man, he even likes him and goes along with him well. We never know what was the kind of relationship between victim and his murderer, it seems that author deliberately omits this part to make the story more disturbing. The one more think we know from the unreliable narrator is that he never craved for the old man’s wealth and possessions. The narrator didn’t know when and why the thought of a murder entered his mind, but the reason he names is even more strange than his previous statements. The old man had a pale blue, deadly and film-covered eye resembling one of a vulture’s. That eye despised the murderer-to-be and drove him mad, so he decided to kill its owner to close it forever.
The killer prepared for a long time and with great care: to avoid future accusation he was incredibly polite with the old man during all the week before the murder. He greeted him every morning and asked him how he slept. But every night, at midnight, he opened the door to the old man's room and watched the sleeping man. He took the lantern with him and watched if the rays of candle light reflect from the surface of the blind eye. But for seven nights the “cursed” eye was closed, so, from the narrator’s point of view, the murder couldn’t be committed.
But on the eighth night everything was different. The narrator slipped into the room again, feeling glee and excitement because he was going to finally do what he planned. He feels like he is able to read the old man’s mind. Firstly the old man wakes up because of a sudden sound when the narrator lifts the latch on his door and is horrified by it. But then he lays back down and goes to sleep again. The murderer opens the flap of the lantern again to see if the eye is opened. The lantern clicks loudly and the narrator hears the frequent knocking of the heart of the alarmed victim, which is getting louder and louder. Afraid that this sound would attract the neighbor's attention, the murderer rushes to the old man with a cry. The old gentleman managed to scream once, but the narrator dragged him to the floor and crushed him with a heavy bed, strangling the victim. The old man's heart was silenced.
The murderer cold-bloodedly lifts the bed and cuts the body into five pieces hiding it under the wooden floor. He planned everything so perfectly that he leaves no trace, he even doesn’t need to wash the blood from anywhere. The tone of his description of this deed is calm and cold. He tries to prove that he isn’t actually insane and that his mind is still sharp enough to calculate such a plan, but the words narrator chooses create a completely opposite image of a dangerous and deranged madman.
The next day three policemen come to investigate the old man’s disappearance. The third man in the house, the neighbor of a murderer, called them hearing the old man screaming at night. The murderer is perfectly collected and serene. He says them that he had bad dreams the night before and the neighbor mistook his scream with the old man’s. The old man, according to his words, just left the city. The policemen find this version plausible but they still ask to show them the house for inspection. The narrator shows every room to the policemen and they find no evidence there. They settle down for casual conversation in that very room where the corpse was hidden.
It seems that the danger of revelation is over, but suddenly the murderer starts hearing the sound of heartbeat from under the floor. Faint at the beginning it becomes louder and the murderer starts to panic thinking that policemen can hear it too. Trying to distract them from that sound the narrator starts speaking louder and louder, finally breaking down, cursing, thrashing the furniture and screaming, but nothing he can do is louder than the sound of the tell-tale heart of the dead old man.
Being sure that policemen know everything and are just mocking him pretending not to hear anything, the murderer confesses to the crime begging to raise the boards and silence the heart beating under them.
Though this story shares some common traits with other horror stories of Edgar Allan Poe such as strange illness sharpening the senses and the victims accusing their murderers, this one is particularly unsetting thanks to its accurate description of what a mental illness is. What the reader sees as lunatic’s delusions is perfectly logical for the narrator. Moreover, he does have enough logic and common sense to prepare the murder and to cover the traces after it. It’s the reason that is completely and horrifyingly random.
The way the author connects some inhuman logic, hearing non-existing sounds and voices with a calculative and rational mind resembles the very nature of mental illnesses, particularly schizophrenia. Also the changes in writing style while the author transits from the descriptive sentences to short, fast and abrupt exclamations when the murderer starts to panic make the reader feel this panic also. It feels like at the beginning of the story the narrator tries to prove his sanity not to the reader but to himself, hiding that raging and horrified state behind the cold and emotionless behaviour.
This novel most clearly shows the interest of Edgar Allan Poe in psychology and psychiatry. He uses his knowledge in all his works but “The Tell-Tale Heart” is the fullest and the most precise depiction of human insanity that touches the primal fears of the readers.