The narrator of "The Tell-Tale Heart" knows everything that happens in the story, as he is the one recounting the events that transpire. He is the one who commits the murder and then tries to cover it up by convincing the reader that he is sane and in control of his actions. However, as the story progresses, it becomes clear that the narrator's mental state is deteriorating, and his guilt and paranoia start to consume him. Ultimately, the narrator's knowledge of his own actions leads to his downfall as he is driven to confess his crime due to the overwhelming guilt and the sound of the victim's heartbeat haunting him.
