"Don't worry," said Grady, easily, "we're not going to injure it. And I think we'll be ready to surrender it to you at any time after to-night. Moosseer Piggott here wants to do a few tricks with it first. I suppose you have a certain right to be present--so, if you like sleight-of-hand, sit down." I hastily sought a chair, my heart singing within me. Then I attempted to assume a mask of indifference, for M. Pigot was obviously annoyed at my presence, and I feared for a moment that his Gallic suavity would be strained to breaking. But Grady, if he noticed his guest's annoyance, paid no heed to it; and I began to suspect that the Frenchman's courtesy and good-breeding had ended by rubbing Grady the wrong way, they were in such painful contrast to his own hob-nailed manners. Whatever the cause, there was a certain malice in the smile he turned upon the Frenchman. "And now, Moosseer Piggott," he said, settling back in his chair a little farther, "we're ready for the show." "What I have to tell you, sir," began M. Pigot, in a voice as hard as steel and cold as ice, "has, understand well, to be told in confidence. It must remain between ourselves until the criminal is secured." Grady's smile hardened a little. Perhaps he did not like the imperatives. At any rate, he ignored the hint. "Understand, Mr. Lester?" he asked, looking at me, and I nodded. I saw Pigot's eyes flame and his face flush with anger, for Grady's tone was almost insulting. For an instant I thought that he would refuse to proceed; but he controlled himself. Standing there facing me, in the full light, it was possible for me to examine him much more closely than had been possible on board the boat, and I looked at him with interest. He was typically French, --smooth-shaven, with a face seamed with little wrinkles and very white, eyes shadowed by enormously bushy lashes, and close-cropped hair as white as his face. But what attracted me most was the mouth --a mouth at once delicate and humourous, a little large and with the lips full enough to betoken vigour, yet not too full for fineness. He was about sixty years of age, I guessed; and there was about him the air of a man who had passed through a hundred remarkable experiences, without once losing his aplomb. Certainly he was not going to lose it now. "The story which I have to relate," he began in his careful English, clipping his words a little now and then, "has to do with the theft of the famous Michaelovitch diamonds. You may, perhaps, remember the case."