The disease which had thus entombed the lady in the maturity of youth, had left, as usual in all maladies of a strictly cataleptical character, the mockery of a faint blush upon the bosom and the face, and that suspiciously lingering smile upon the lip which is so terrible in death. We replaced and screwed down the lid, and, having secured the door of iron, made our way, with toil, into the scarcely less gloomy apartments of the upper portion of the house. Which statement best describes how Poe develops a specific element of American Gothic fiction in the excerpt?