But even as these thoughts came to him he wondered at the source of his strange confidence. Did all of this perilous sense of imminence come from the formulae on the sheets he covered day by day? The soft, stealthy, imaginary footsteps in the sealed loft above were unnerving. And now, too, there was a growing feeling that somebody was constantly persuading him to do something terrible which he could not do. How about the somnambulism? Where did he go sometimes in the night? And what was that faint suggestion of sound which once in a while seemed to trickle through the confusion of identifiable sounds even in broad daylight and full wakefulness? Its rhythm did not correspond to anything on earth, unless perhaps to the cadence of one or two unmentionable Sabbat-chants, and sometimes he feared it corresponded to certain attributes of the vague shrieking or roaring in those wholly alien abysses of dream.