"Oh," said the detective thoughtfully, "that's different. Thank you, sir," nodding to the new-comer. "I'm afraid your name isn't known to me, but if you can give us a tip or two I shall be grateful. I wish Inspector Sheffield were here. These cases are fair nightmares to me. And now it's got to murder, life won't be worth living at the Yard if we don't make an arrest." "Yes, yes," said Dr. Lepardo, peering about him, speaking in a most peculiar, rumbling tone, and with a strong accent. "I would not have missed such a chance. Where is this dagger? I have just returned from the Izamal temples of Yucatan. I have brought some fine specimens to Europe. Obsidian knives. Sacrificial. Beautiful." He shuffled jerkily into the private office, seemed to grasp its every detail in one comprehensive, peering glance, and pounced upon the dagger with a hoarse exclamation. The Scotland Yard man watched him with curiosity, and Julius Rohscheimer, in the open door, followed his movements with a newly awakened interest. "True Damascus!" he muttered, running a long finger up the blade. "Hilt, Persian--not Kultwork--Persian. Yes. Can I pull it out? Yes? Damascened to within three inches. Very early." He turned to the detective, dagger in hand. "This is a Turkish yataghan." No one appeared to be greatly enlightened. "When I say a Turkish yataghan I mean that from a broken Damascus sword-blade and a Persian dagger handle, a yataghan of the Turkish pattern has been made. There are stones incrusted in the hilt but the blade is worth more. Very rare. This was made in Persia for the Turkish market." "One of Severac Bablon's Arabs," burst in Rohscheimer hoarsely, "has done this." "Ah, yes. So? I read of him in Paris. He is in league with the chief of the Paris detective. Him? So. I meet him once." "Eh?" cried Harborne, "Severac Bablon?" Julius Rohscheimer's eyes grew more prominent than usual. "No, no. The great Lemage. Lemage of Paris--his accomplice. This dagger is worth two thousand francs. Let me see if a Turk has been in these rooms. I meet Victor Lemage on such another occasion with this. He say to me, 'Dr. Lepardo, come to the Rue So-and-such. A young person is stabbed with a new kind of knife.' I tell him, 'It is Afghan, M. Lemage.' He find one who had been in that country, arrest--and it is the assassin. There is no smell of a Turk here. Ah, yes. The Turk, he have a smell of his own, as have the negro, the Chinese, the Malay." Pulling a magnifying-glass from one bulging pocket of his inverness, Dr. Lepardo went peering over the writing desk, passing with a grunt from the bloodstained paper bearing the name of Severac Bablon to the other documents and books lying there; to the pigeon-holes; to the chair; to the rug; to the body. Crawling on all fours he went peering about the floor, scratching at the carpet with his long nails like some monstrous, restless cat. Harborne glanced at Dr. Simons and tapped his forehead significantly.