"If that document were to get to a certain Embassy in London no one can foretell the calamitous results. It might even result in another war, if not now certainly later. It was, I should explain, of a private and confidential nature, and consequently quite frankly expressed." "And you must remember----" began Mr. Llewellyn John excitedly. "One moment, sir," said Malcolm Sage quietly, without looking up from an absorbed contemplation of a bronze letter-weight fashioned in the form of a sphinx. Mr. Llewellyn John sank back into his chair, and Sir Lyster resumed. "Just over an hour and a half ago, that is to say soon after eleven o'clock, it was discovered that the document in question was missing, and in its place had been substituted a number of sheets of blank paper." "Unless it's found, Sage," cried Mr. Llewellyn John, jumping up from his chair in his excitement, "the consequences are too awful to contemplate." For a few seconds he strode up and down the room, then returning to his chair, sank back into its comfortable depths. "Where was the document kept?" enquired Malcolm Sage, his long, sensitive fingers stroking the back of the sphinx. "In the safe," replied Sir Lyster, indicating with a nod a small safe let into the wall. "You are in the habit of using it for valuable documents?" queried Malcolm Sage. "As a matter of fact very seldom. It is mostly empty," was the reply. "Why?" "I have a larger safe in my dressing-room, in which I keep my papers. During the day I occasionally use this to save going up and down stairs." "Where do you keep the key?" "When there is anything in the safe I always carry it about with me." "And at other times?" "Sometimes in a drawer in my writing-table," said Sir Lyster; "but generally I have it on me." "When was the document put into the safe?" "At a quarter to eight to-night, just as the second dressing-gong was sounding." "And you yourself put it in, locked the door, and have retained the key ever since?" Malcolm Sage had exhausted the interest of the sphinx and was now drawing diagrams with his forefinger upon the morocco surface of the table. Sir Lyster nodded. "I put the key in the pocket of my evening vest when I changed," he said. "After the other guests had retired, the Prime Minister raised a point that necessitated reference to the document itself. It was then I discovered the substitution." "But for that circumstance the safe would not have been opened until when?" queried Malcolm Sage. "Late to-night, when I should have transferred the packet to the safe in my dressing-room." "Would you have examined the contents?" "No. It is my rule to cut adrift from official matters from dinner-time on Saturday until after breakfast on Monday. It was only in deference to the Prime Minister's particular wish that we referred to the document to-night." "I take it that the rule you mention is known to your guests and servants?" "Certainly."