But before long that room over mine acquired for itself in my mind a new and dread significance. A consciousness gradually grew upon me that there was about it something quite out of the common way; that its four walls held within themselves some grim secret, the rites appertaining to which were gone through when I and the rest of the uninitiated were supposed to be in bed and asleep. I cannot tell what it was that first made me suspect the existence of this secret. Certainly not the midnight walks of Lady Pollexfen. Perhaps a certain impalpable atmosphere of mystery, which, striking keenly on the sensitive nerves of a child, strung by recent events to a higher pitch than usual, broke down the first fine barrier that separates things common and of the earth earthy, from those dim intuitions which even the dullest of us feel at times of things spiritual and unseen. But however that may be, it so fell out that I, who at school had been one of the soundest of sleepers, had now become one of the worst. It often happened that I would awake in the middle of the night, even when there was no Lady Pollexfen to disturb me, and would so lie, sleepless, with wide-staring eyes, for hours, while all sorts of weird pictures would paint themselves idly in the waste nooks and corners of my brain. One fancy I had, and for many nights I thought it nothing more than fancy, that I could hear soft and muffled footsteps passing up and down the staircase just outside my door; and that at times I could even faintly distinguish them in the room over mine, where, however, they never stayed for more than a few minutes at any one time. In one of my daylight explorations about the old house I ventured up the flight of stairs that led from the landing outside my door to the upper rooms. At the top of these stairs I found a door that differed from every other door I had seen at Dupley Walls. In colour it was a dull dead black, and it was studded with large square-headed nails. It was without a handle of any kind, but was pierced by one tiny keyhole. To what strange chamber did this terrible door give access? and who was the mysterious visitor who came here night after night with hushed footsteps and alone? These were two questions that weighed heavily on my mind, that troubled me persistently when I lay awake in the dark, and even refused by day to be put entirely on one side.