"The Tell-Tale Heart" is a first-person narrative of an unnamed narrator, who insists that they are sane, but is suffering from a disease (nervousness) which causes "over-acuteness of the senses". Due to the ambiguity surrounding the identity of the story's narrator, the narrator's gender is uncertain.

The old man with whom the narrator lives has a clouded, pale, blue "vulture-like" eye, which distresses the narrator so much that they plot to murder the old man, despite also insisting that they love the old man. The narrator insists that their careful precision in committing the murder proves that the narrator cannot possibly be insane. For seven nights, the narrator opens the door of the old man's room in order to shine a sliver of light onto the "evil eye". However, the old man's vulture-eye is always closed, making it impossible to "do the work".

On the eighth night, the old man awakens after the narrator's hand slips and makes a noise, interrupting the narrator's nightly ritual. But the narrator does not draw back and, after some time, decides to open the lantern. A single thin ray of light shines out and lands precisely on the "evil eye", revealing that it is wide open. Hearing the old man's heart beating loudly and dangerously fast from terror, the narrator decides to strike, jumping out with a loud yell and smothering the old man with his own bed.

For more information click