“Yes, we shall make our little ambush here. Get into this hollow, Lestrade. You have been inside the house, have you not, Watson? Can you tell the position of the rooms? What are those latticed windows at this end?”

“I think they are the kitchen windows.”

“And the one beyond, which shines so brightly?”

“That is certainly the dining-room.”

“The blinds are up. You know the lie of the land best. Creep forward quietly and see what they are doing—but for heaven’s sake don’t let them know that they are watched!”

I tiptoed down the path and stooped behind the low wall which surrounded the stunted orchard. Creeping in its shadow I reached a point whence I could look straight through the uncurtained window.

There were only two men in the room, Sir Henry and Stapleton. They sat with their profiles towards me on either side of the round table. Both of them were smoking cigars, and coffee and wine were in front of them. Stapleton was talking with animation, but the baronet looked pale and distrait. Perhaps the thought of that lonely walk across the ill-omened moor was weighing heavily upon his mind.

As I watched them Stapleton rose and left the room, while Sir Henry filled his glass again and leaned back in his chair, puffing at his cigar. I heard the creak of a door and the crisp sound of boots upon gravel. The steps passed along the path on the other side of the wall under which I crouched. Looking over, I saw the naturalist pause at the door of an out-house in the corner of the orchard. A key turned in a lock, and as he passed in there was a curious scuffling noise from within. He was only a minute or so inside, and then I heard the key turn once more and he passed me and reentered the house. I saw him rejoin his guest, and I crept quietly back to where my companions were waiting to tell them what I had seen.

“You say, Watson, that the lady is not there?” Holmes asked when I had finished my report.

“No.”

“Where can she be, then, since there is no light in any other room except the kitchen?”

“I cannot think where she is.”

I have said that over the great Grimpen Mire there hung a dense, white fog. It was drifting slowly in our direction and banked itself up like a wall on that side of us, low but thick and well defined. The moon shone on it, and it looked like a great shimmering ice-field, with the heads of the distant tors as rocks borne upon its surface. Holmes’s face was turned towards it, and he muttered impatiently as he watched its sluggish drift.

“It’s moving towards us, Watson.”

“Is that serious?”