I was irresolutely speculating on when I had better attack the northward door, and on how I could least audibly manage it, when I noticed that the vague noises underfoot had given place to a fresh and heavier creaking of the stairs. A wavering flicker of light shewed through my transom, and the boards of the corridor began to groan with a ponderous load. Muffled sounds of possible vocal origin approached, and at length a firm knock came at my outer door.