We passed down the passage, which was of the same length as that which led to the garden. At the end was a short flight of steps ending in a door. Our guide knocked, and then ushered us into the professor’s bedroom.

It was a very large chamber, lined with innumerable volumes, which had overflowed from the shelves and lay in piles in the corners, or were stacked all round at the base of the cases. The bed was in the centre of the room, and in it, propped up with pillows, was the owner of the house. I have seldom seen a more remarkable-looking person. It was a gaunt, aquiline face which was turned towards us, with piercing dark eyes, which lurked in deep hollows under overhung and tufted brows. His hair and beard were white, save that the latter was curiously stained with yellow around his mouth. A cigarette glowed amid the tangle of white hair, and the air of the room was fetid with stale tobacco smoke. As he held out his hand to Holmes, I perceived that it was also stained with yellow nicotine.