The interval was too brief to be artificially measured, between the utterance of these words, and my scrutiny directed to the quarter whence they came. Yet if a human being had been there, could he fail to have been visible? Which of my senses was the prey of a fatal illusion? The shock which the sound produced was still felt in every part of my frame. The sound, therefore, could not but be a genuine commotion. But that I had heard it, was not more true than that the being who uttered it was stationed at my right ear; yet my attendant was invisible.
I cannot describe the state of my thoughts at that moment. Surprise had mastered my faculties. My frame shook, and the vital current was congealed. I was conscious only to the vehemence of my sensations. This condition could not be lasting. Like a tide, which suddenly mounts to an overwhelming height, and then gradually subsides, my confusion slowly gave place to order, and my tumults to a calm. I was able to deliberate and move. I resumed my feet, and advanced into the midst of the room. Upward, and behind, and on each side, I threw penetrating glances. I was not satisfied with one examination. He that hitherto refused to be seen, might change his purpose, and on the next survey be clearly distinguishable.
Solitude imposes least restraint upon the fancy. Dark is less fertile of images than the feeble lustre of the moon. I was alone, and the walls were chequered by shadowy forms. As the moon passed behind a cloud and emerged, these shadows seemed to be endowed with life, and to move. The apartment was open to the breeze, and the curtain was occasionally blown from its ordinary position. This motion was not unaccompanied with sound. I failed not to snatch a look, and to listen when this motion and this sound occurred. My belief that my monitor was posted near, was strong, and instantly converted these appearances to tokens of his presence, and yet I could discern nothing.