She shook her head in feeble impotence, feeling how weak she was to combat this fixed belief. It was the old story over again. Nevertheless she made one more effort. Mr. Strange was watching her.

"Sir, I do not know what to say more than I said before. But I declare to you once again, as solemnly as I can ever speak anything in this life, as solemnly as I shall one day have to answer before my Maker, that I know nothing of Philip Salter. He never was here at all to my knowledge, later or earlier. Why will you not leave me in peace?"

Mr. Detective Strange began to think that he should have to leave her in peace. Twice had he carried this fortress by storm to search at will its every nook and corner: and searched in vain. Armed with great power though he was, the law would not justify these repeated forcible entries, and he might be called to account for exceeding his duty. But the man was there--as surely as that the sun was in the heavens: and yet he could not unearth him. He began to think there must be caves underground impenetrable to the eye of man, with some invisible subtle entrance to them through the earth itself--and perhaps a subterranean passage communicating with Mr. Smith's abode opposite.

And so, the second search ended as the first had done--in signal failure. Once more there was nothing left for the detective but to withdraw his men and himself, and to acknowledge that he was for the time defeated.

[CHAPTER XVI.]

Up the Spouts and down the Drains.

Turning his face towards the railway station after quitting the Maze, with the view of making some enquiries, as to what passengers had alighted there the previous day and had gone back again--not that he believed one syllable of the tale told him--Mr. Strange encountered the gig of Dr. Cavendish bowling down. The physician recognised him and pulled up.

"What's this I hear, sir, about my patient's having gone off again?" cried the doctor in a sharp tone.

"I have heard the same," replied Mr. Strange. "But I don't believe it."

"Oh then--you are not privy to it? You did not send him?"