Towards the blackest of these the dog led, and entered a hollow way.

Richard went straight after him, guarding his head with his arm, lest he might meet a sudden descent of the roof, and lengthening his leash to the utmost, that he might have timely warning of any descent of the floor.
It was a very rough tunnel, the intent of which will afterwards appear, forming part of one of lord Herbert's later contrivances for the safety of the castle; but so well had Mr.Salisbury, the surveyor, managed, that not one of the men employed upon it had an idea that they were doing more than working the quarry for the repair of the fortifications.
From the darkness, and the cautious rate at which he had to proceed, holding back the dog who tugged hard at the whip, Richard could not even hazard a conjecture as to the distance they had advanced, when he heard the noise of a small runnel of water, which seemed from the sound to make abrupt descent from some little height.

He had gone but a few paces further when the handle of the whip received a great upward pull and was left loose in his grasp: the dog was away, leaving his handkerchief at the end of the thong.

So now he had to guide himself, and began to feel about him.

He seemed at first to have come to the end of the passage, for he could touch both sides of it by stretching out his arms, and in front a tiny stream of water came down the face of the rough rock; but what then had become of Marquis?
The answer seemed plain: the water must come from somewhere, and doubtless its channel had spare room enough for the dog to pass thither.