and
bristling chimneys hard outlined against the silver-spangled sky. Broad
bars of golden light from the lower windows stretched across the orchard
and the moor. One of them was suddenly shut off. The servants had left
the kitchen. There only remained the lamp in the dining-room where the
two men, the murderous host and the unconscious guest, still chatted
over their cigars.

Every minute that white woolly plain which covered one-half of the moor
was drifting closer and closer to the house. Already the first thin
wisps of it were curling across the golden square of the lighted window.
The farther wall of the orchard was already invisible, and the trees
were standing out of a swirl of white vapour. As we watched it the
fog-wreaths came crawling round both corners of the house and rolled
slowly into one dense bank on which the upper floor and the roof
floated like a strange ship upon a shadowy sea. Holmes struck his hand
passionately upon the rock in front of us and stamped his feet in his
impatience.

"If he isn't out in a quarter of an hour the path will be covered. In
half an hour we won't be able to see our hands in front of us."

"Shall we move farther back upon higher ground?"

"Yes, I think it would be as well."

So as the fog-bank flowed onward we fell back before it until we were
half a mile from the house, and still that dense white sea, with the
moon silvering its upper edge, swept slowly and inexorably on.

"We are going too far," said Holmes. "We dare not take the chance of his
being overtaken before he can reach us. At all costs we must hold our
ground where we are." He dropped on his knees and clapped his ear to the
ground. "Thank God, I think that I hear him coming."

A sound of quick steps broke the silence of the moor. Crouching among
the stones we stared intently at the silver-tipped bank in front of us.
The steps grew louder, and through the fog, as through a curtain, there
stepped the man whom we were awaiting. He looked round him in surprise
as he emerged into the clear, starlit night. Then he came swiftly along
the path, passed close to where we lay, and went on up the long slope
behind us. As he walked he glanced continually over either shoulder,
like a man who is ill at ease.

"Hist!" cried Holmes, and I heard the sharp click of a cocking pistol.
"Look out! It's coming!"

There was a thin, crisp, continuous patter from somewhere in the heart
of that crawling bank. The cloud was within