Read the excerpt from Poe’s "The Fall of the House of Usher."Shaking off from my spirit what must have been a dream, I scanned more narrowly the real aspect of the building. Its principal feature seemed to be that of an excessive antiquity. The discoloration of ages had been great. Minute fungi overspread the whole exterior, hanging in a fine tangled web-work from the eaves.Which short story element does Poe develop in the excerpt?