He separated the edges now, worked his fingers into the opening, and drew out an envelope. It had been torn open at one end, and there was a superscription of some sort on it in faded writing which, in the semi-darkness, he could not make out. He stood up, and went quickly to the window to obtain the full benefit of the moonlight. He could just decipher the writing now:

"Polly's papers which is God's truth,
Mrs. Wickes X her mark."

For a moment he stood there motionless—but his eyes had lifted from the envelope now and were fixed on the lawn below. The window here gave on the side of the lawn with the trees at the rear of the house in view. A man had just stepped out from the shadow of the trees and was coming toward the house.

Locke stared, even the envelope in his hand temporarily forgotten, as a frown of perplexity that deepened into amazed chagrin gathered on his forehead. The figure was quite recognisable, even minutely so. It was Captain Francis Newcombe. It accounted for the missing sockets on that French window perhaps—but the man was as perfectly and immaculately dressed as he had been that night at dinner. There was no torn coat—on missing coat sleeve. The man he had fought with, the man in the mask, had not been Captain Francis Newcombe.

He laughed now—not pleasantly. He had obviously been waiting here for the wrong man. There was no need of waiting any longer—unless he desired to be caught himself! Queer! Strange! But there was the envelope. Polly's papers! What was it that was "God's truth"? At least, he would find that out!

He thrust the envelope into his pocket, closed the bag, and returned to his own room. He switched on the light, hurriedly took the envelope from his pocket again, and from it drew out two documents. He studied them while minute after minute passed, then dropping them on the table before him, he stood with drawn face and clenched fists staring across the room. Polly's birth certificate! The marriage certificate of her parents! He saw again the agony in the dark eyes, he heard again the agony in the voice that had proclaimed a parentage outside the pale. And a great oath came now from Locke's white lips.

He flung himself into a chair beside the table. He fought for cool, contained reasoning. These papers—Newcombe! Did it change anything, place Newcombe in any better light, because it was some other man who had worn that mask to-night? He shook his head in quick, emphatic dissent. It did not! He was sure, certain of that. The trail led too far back, was too well defined, too conclusive. And even to-night! What was Newcombe doing out of the house at three o'clock in the morning? Ah, yes—he had it! The old maniac's words came back with sudden and sure significance: "Digging—digging—digging.... The wrong scent.... The hut in the woods at the rear of the house."

Locke gnawed savagely at his lips. That was where Newcombe had come from—the woods at the rear of the house. It meant that Newcombe was the one who had been tricked by the old madman's cunning, which could never have happened if Newcombe had not been stealthily trying to find the hidden money; it simply meant that Newcombe was the one who had been on the wrong scent—and that some one else had been on the right one!

His face was set in lines like chiselled marble now. Who was this "some one else"? Was the question very hard to answer? The field was very limited—significantly limited now! He wasn't wrong, was he? He couldn't be wrong! And there was always the torn sleeve!

Locke's eyes fixed upon the two documents on the table again. Captain Francis Newcombe! No; it did not make Newcombe any the less a guilty man because it was not he who had worn the mask to-night. Newcombe stood out sharply defined against the light of evidence which, if only circumstantial, was strong enough to damn the man a thousand times over for what he was. And here, adding to that evidence, was the proof that Polly's identity had been, and was being, deliberately concealed from her. It opened a vista to uglier and still more evil things—things that only a soul dead to decency, black as the pit of hell, could have conceived and patiently put into execution. A child—a gutter-snipe, Polly had called herself—rescued from naked poverty and the slums of Whitechapel by a man such as Newcombe, whose only promptings were the promptings of a fiend! Why? Was there room to question further why Captain Francis Newcombe had years ago adopted such a ward—when now before one's eyes those years were bearing their poison fruit? Polly's introduction into this family here was even at this moment being traded upon to effect the theft of half a million dollars. That was too obvious now to permit denial. Newcombe was making of a girl, high-minded, pure-souled, a hideous cat's-paw. Yes, yes! All that was clear enough! But why should Polly have been deprived of her rightful name, her claim to honest parentage? Was it to weld a stronger bond of gratitude—or make her the more helpless, and therefore the more dependent upon her guardian? Where were these parents? Dead or living? There was Mrs. Wickes—Mrs. Wickes, who had posed as the mother! Well, there were certain quarters in London where those who strayed outside the law could be made to talk. Mrs. Wickes should be able to furnish very interesting information. It was not far to Whitechapel and London—by cable.