Interestingly, "The House of Usher" is a double-entendre, meaning both the architectural structure that is the home of Roderick and Madeline and the lineage of the Usher name. This mansion, once structurally sound, aristocratic, aesthetic, now parallels the family of Usher in its decrepitude. Because the Ushers have kept their bloodlines too thin, Madeline and Roderick possess, mysterious illnesses; Roderick describes his malady as "a constitutional and a family evil " without remedy. In addition, the Usher line has ben reduced to Roderick and Madeline, who are twins, male and female counterparts of each other; Madeline, too, has a disease that "baffles the skill of the physicians." Twin that he is, Roderick senses Madeline's condition, and he fears being separated from her as though this separation will deprive him, too, of life.
Madeline dies, Roderick moves her to a vault hoping to preven her being examined in an autopsy, His behavior becomes erratic and bizarre like the fissures in the house. His is a "sensitive nervousness," mirroring the cataleptical condition of his sister in emotion. In hysteria the ailing Roderick says that his supersenative ears hear Madeline, and she is at the door. With preternatural energy he unbolts a door and in "death agonies" Madeline and he fall dead. Like the family, the decaying house crumbles.
Roderick, Madeline and the house seem to be bound together, at both literally and figuratively. When the narrator enters, he notices a large crack in the house. This reflects the crack or separation that has occurred between Roderick and Madeleine. Roderick informs the narrator that he and his sister are twins and that she is ill. Roderick himself seems to be suffering from illness, both physical and mental. The house is also "ill". It is run down and needs repairs. It is also surrounded by a dank or smelly tarn or moat. This suggests the separation between the Ushers and the outside world. As the story continues, the house begins to creak, strange sounds come from the cellar and the narrator begins to hear Madeline trying to escape the coffin in which she's been placed. All this occurs while Roderick sinks deeper into madness. At the end of the story, all three of the subjects, Roderick, Madeline and the house are destroyed. The crack in the house begins to split open, representing the madness and split in the minds of the Ushers. Finally, house ,which contains their bodies, slips into the dark tarn. Thus, they all share the same fate in the end--destruction and death as the narrator barely escapes.