The narrator arrives on a bleak autumn day at the melancholy House of Usher, summoned by a frantic letter from his childhood friend Roderick Usher. Upon approaching the ancient mansion, which comprises both the deteriorating family estate and the doomed bloodline itself, the narrator is immediately overcome by an oppressive sense of gloom and an inexplicable dread. Inside, he finds Roderick drastically altered, suffering from an acute sensory disorder, extreme nervous agitation, and a profound terror of his own impending psychological ruin.
Roderick lives as a recluse within the gloomy, cavernous halls, paralyzed by superstitious beliefs concerning the sentient nature of the family's masonry and the surrounding stagnant tarn. His only remaining companion is his twin sister, Lady Madeline, whose chronic, wasting illness and cataleptic seizures baffle her physicians. When Madeline seemingly succumbs to her affliction, Roderick decides to temporarily entomb her within a reinforced subterranean vault beneath the house to prevent her body from being scrutinized by local doctors and to shield her from the damp, exposed family burial ground.
Over the next several days, Roderick's erratic behavior intensifies into a state of frantic terror, and the narrator finds his own sanity increasingly infected by the heavy atmosphere of the house. On a stormy night, unable to sleep, the narrator attempts to calm his host by reading aloud from an old chivalric romance. As he reads descriptions of breaking doors and falling shields, muffled echoes of these exact sounds begin to reverberate through the distant corridors of the mansion.
In a harrowing climax, a frantic Roderick confesses that he has known for days that they buried Madeline alive and that her muffled struggles have been echoing through the stone walls. As he screams in terror that she stands outside the door, the heavy panels blow open to reveal the blood-stained, enshrouded figure of Lady Madeline. With a final, agonizing cry, she collapses upon her brother, dragging him to the floor in death.
Seized by absolute horror, the narrator flees the mansion across the causeway into the storm. Looking back, he watches as a fierce whirlwind shatters the moonlight streaming through a widening zigzag fissure in the ancient stone walls. The House of Usher tears violently asunder, and the dark tarn closes silently over the ruins, erasing the family name and estate forever.
