Moore calmly shook hands and mumbled something, and then, in a side whisper to me, said: "It's up to you, Stone; say something." Although I was nearly as surprised as he, I managed to make a few audible remarks about how glad the town would be to know that Quintus Oakes was here. I saw a merry twinkle in Hallen's eyes, but the stranger made a suitable reply, and left us with that peculiar business-like air of his. I turned to Moore and half-gasped: "What does this mean, old man?" "A decoy," said he. "Just keep your nerve. Hallen has been giving us practice in acting." The by-standers and the groups in the street were discussing the stranger with peculiar, suppressed excitement. Many of the smart ones claimed to have seen him before and to know all about him; already, "Quintus Oakes" rang familiarly from their lips. We presently returned to the Mansion and related to our leader the facts we had learned from Reilly regarding "the woman's" appearances before the murder, the sudden ending of both the milkmen who had seen her, and Reilly's own suspicions in the matter. Oakes was thoughtful for quite a while. "You have done more than I thought you could in so brief a time," said he at last. "Have you any theories regarding the identity of the woman?" We had none to offer, and he began to smile ever so slightly. "Well, it seems to me your woman is a mistake--there was no woman. The assassin was a man in a black robe. He ran heavily, of course. You have drawn the murderer of Smith nearer to that of Mark. As regards the sudden deaths of the milkmen, probably both were killed; the examinations after death, conducted as these were, amount to nothing. The murderer of Smith, the two milkmen and of Mark is probably one and the same. Stone, you nearly fell a victim at the bridge the other night, too." I did not reply, but a cold perspiration broke out over me. The chain of events seemed clearer now in the light of Oakes's reasoning. Then he turned to Moore. "Doctor, loan me your cigar-cutter, will you?" The physician reached for it, but it was gone. "I think this must be it," said Oakes, holding out the missing article. "Next time you hide on your stomach behind a tree, do it properly." Moore was dumfounded. "What!" I cried, "you know that too? We did not tell you." "No, you did not. You began your narration at the wrong end--or perhaps you _forgot_," and his eyes twinkled. "But how did you learn of it?" demanded Moore, recovering. And Quintus smiled outright. "My man was behind another tree only ten feet away from you the whole time. When you left, he picked up this as a memento of your brilliant detective work." Moore and I smarted a little under the sarcasm, and I asked what the man was doing there. "Oh, he was watching Mike and, incidentally, keeping you two from mischief. You need a guardian. You never even suspected his presence, and--suppose he had been the assassin!"