“Both doors are locked, Mr. Chinje,” he said. “For the time being we are virtually prisoners.” “Give me the case,” said his father, selecting the key of the door communicating with his private office. “There is no occasion for further delay.” The Lord Mayor turned from the window, through which he had still been vainly peering, and stepped to the table. “Mr. Anderson!” “Yes?” said the latter, glancing back, keys in hand. “Have you the diamond?” “Certainly not!” “Then who has it?” No one had it. But the case was empty! III Mr. Anderson replaced the keys in his pocket. His ruddy face suddenly had grown pale. Sir Michael Cayley, the empty case in his hand, stood staring across the room like a man dazed. Then he forced speech to his lips. “Gentlemen,” he said, “since it is physically impossible for the diamond to have left this room, in this room it must be searched for--and found. First, is it by any chance upon the floor?” A brief examination showed that it was not. “Then,” continued Sir Michael, “the painful conclusion is unavoidable that it is upon someone’s person!” An angry murmur arose. Mr. Anderson raised his hand. “Gentlemen,” he said, “Sir Michael states no more than the fact.” And, his face remaining very pale, he removed his coat and waistcoat and threw them upon the table, emptied his trouser pockets and turned out the linings. “Be good enough to examine them, gentlemen,” he said. There was a momentary hesitation; but the Lord Mayor stepped forward and in a businesslike way examined the contents of the several pockets. He turned to Mr. Anderson. “Thank you,” he said. “If the others are satisfied, I am.” There was a murmur of assent; and as the owner of the office picked up his property, Sir Michael, in turn, submitted himself to examination. All the others followed suit, without further hesitation. And the result of the inquiry was _nil_. Eight anxious faces surrounded the little table. “I suggest,” said Mr. Anderson, quietly, “that we admit the detective who is in my office. His experience may enable him to succeed where we have failed.” All agreeing, the communicating door was opened. Mr. Anderson, without quitting the room, called to Inspector Grimsby. The inspector entered. The door was relocked. “Inspector,” said Mr. Anderson, “the diamond is missing!” Whereupon Grimsby’s eyes opened widely in amazement. “Are you sure, sir?” “Unfortunately, I cannot doubt it.” “When did you last see it?” “At the moment when that uproar broke out below,” said Mr. Dell. “Ah,” murmured Grimsby, thoughtfully. “You all rushed to the window, I expect?” “Exactly.” “Leaving the diamond on the table?” “Yes.” “That’s when it was stolen!” “Very possibly, Inspector,” said the Lord Mayor, a stoutly built man with an imperious manner. “But who took it and where did he conceal it?” “You must all submit to be searched, gentlemen!” “We have already done so.”