And then, again, with a swift transition of his terrors, the very silence of the place appeared a source of peril, and a thing to strike and freeze the passer-by; and he would step more boldly, and bustle aloud among the contents of the shop, and imitate, with elaborate bravado, the movements of a busy man at ease in his own house.
But he was now so pulled about by different alarms that, while one portion of his mind was still alert and cunning, another trembled on the brink of lunacy.

One hallucination in particular took a strong hold on his credulity.

The neighbour hearkening with white face beside his window, the passer-by arrested by a horrible surmise on the pavement--these could at worst suspect, they could not know; through the brick walls and shuttered windows only sounds could penetrate.

But here, within the house, was he alone?
He knew he was; he had watched the servant set forth sweet-hearting, in her poor best, 'out for the day' written in every ribbon and smile.

Yes, he was alone, of course; and yet, in the bulk of empty house above him, he could surely hear a stir of delicate footing--he was surely conscious, inexplicably conscious of some presence.