In "The Fall of the House of Usher," there is ambiguity surrounding Madeline's death and her return--neither the characters nor the readers know the cause of Madeline's death or if she was actually dead when buried. Soon after the burial, Usher starts to suspect that they had buried Madeline while she was still alive: "...I hear it, and have heard it....Many minutes, many hours, many days, have I heard it...yet I dared not speak! We have put her living in the tomb!" (28). This uncertainty creates trepidation and fear for Usher because he fears Madeline "is...hurrying to upbraid [him] for [his] haste" in burying her; he becomes apprehensive and anxious at the sounds he hears in his house, not knowing if they are coming from the tombs.
The fear and suspense that overcome Usher drives him towards insanity by overwhelming and consuming his life with hysteria and fear of everything around him.
Usher's fears take over his thoughts: "There was a species of mad hilarity in his eyes--an evidently restrained hysteria in his whole demeanor" (25). From being in constant fear and anticipation, Usher's actions become irrational, muttering to himself and "gazing upon vacancy for long hours, in an attitude of the profoundest attention, as if listening to some imaginary sound" (24).
The cause of the hysteria and terror in Usher is unknown to the narrator for most of the story--until Usher finally admits that he suspected he buried Madeline alive. The narrator witnesses the strange changes coming over Usher, which begin to terrify him as they increase. "It was no wonder that his condition terrified--that it infected me. I felt creeping upon me, by slow yet certain degrees, the wild influences of his own fantastic yet impressive superstitions"
(24). The mysteriousness of Usher's condition creates...