The narrator claims that "La enfermedad había agudizado mis sentidos en vez de destruirlos o embotarlos." (The illness had sharpened my senses instead of destroying or dulling them.) The specific nature of this illness is not mentioned.
This video features a human narration of Edgar Allan Poe's short story, "The Tell-Tale Heart." The story is told from the perspective of an unnamed narrator who insists on their sanity while describing a murder they committed, driven by an obsession with the victim's eye. The narration details the meticulous planning and execution of the crime, the subsequent concealment of the body, and the narrator's eventual confession, prompted by the imagined sound of the victim's beating heart.