Poe next sets up a sense of the "double" or the ironic reversal when he has the narrator first see the House of Usher as it is reflected in the "black and lurid tarn" (a dark and gruesome, revolting mountain lake) which surrounds it. The image of the house, you should note, is upside down. At the end of the story, the House of Usher will literally fall into this tarn and be swallowed up by it. And even though Poe said in his critical theories that he shunned symbolism, he was not above using it if such symbolism contributed to his effect. Here, the effect is electric with mystery; he says twice that the windows of the house are "eyelike" and that the inside of the house has become a living "body" while the outside has become covered with moss and is decaying rapidly. Furthermore, the ultimate Fall of the House is caused by an almost invisible crack in the structure, but a crack which the narrator notices; symbolically, this is a key image. Also central to this story is that fact that Roderick and the Lady Madeline are twins. This suggests that when he buries her, he will widen the crack, or fissure, between them. This crack, or division, between the living and the dead will be so critical that it will culminate ultimately in the Fall of the House of Usher.
It is possible that Poe wanted us to imagine that when Usher tries to get rid of that other part of himself, the twin half, he is, in effect, signing his own death warrant. Certainly at the end of the story, Lady Madeline falls upon him in an almost vampire-like sucking position and the two of them are climactically, totally one, finally united in the light of the full moon, by which the narrator is able to see the tumultuous Fall of the House of Usher. (The full moon, of course, is a traditional prop for stories of this sort; that is, one finds it in all gothic, ghostly, and vampire-type stories.)
Upon entering the gothic archway of the deteriorating mansion, the narrator is led "through many dark and intricate passages" filled with "sombre tapestries," "ebon blackness," and "armorial trophies." As noted earlier, these details of old armor standing in the shadows and the intricate passageways leading mysteriously away are all traditional elements in all gothic horror stories. Over everything, Poe drapes his "atmosphere of sorrow . . . and irredeemable gloom." He evokes here his primary effect: We sense that some fearful event will soon transpire.
