What did usher want to do with his twin sisters body of the fall of the house of usher?

In Edgar Allan Poe's "The Fall of the House of Usher," Roderick Usher wanted to entomb his twin sister, Madeline, in a vault within the family mansion after her apparent death. He intended to preserve her body in a sealed chamber, reflecting his deep emotional connection and fear of losing her completely. This act, however, leads to haunting consequences, as Madeline ultimately returns from the grave, culminating in the story's tragic climax.