"I got in," he said briefly. "I was only there two minutes, at a liberal computation, but I've found out and done all I required. He's dining out to-night. The books, as you expected, are in an ordinary bookcase, glass fronted, with an ordinary padlock on it. What fools these War Office experts are! There was a spare latch-key of his rooms hanging on a hook on the wall, for the servant, I suppose. I nicked it as I went out. I met the servant on the stairs--just as well, if I run across him to-night. There will be nothing rummy in my returning to see his master. I purposely dragged my coat against the passage whitewash, and after he offered to brush it for me I gave him half a crown. So he's all right; he thinks I'm a worthy gentleman who ought to be encouraged to call often. Is that all right?" Mr. Miller smiled. "You show such talents and attention to detail, my dear Lord Landon," he answered, "that I grieve that I am not the happy partner of such a colleague permanently." Landon looked across at him with a grin. "Seriously?" he demanded. "Quite seriously," replied the impassive Mr. Miller. Landon meditated. "If there is good money in it--?" he mused slowly, but his host hastened to interrupt him energetically. "Excellent money," he assured him, "and we have always a use for a lord." Landon grinned again. "Perhaps my value will increase after this evening," he suggested. "When do you purpose going?" "Would half-past nine suit you?" said Miller, affably, and Landon nodded. "Charmed, I'm sure," he grinned again, and tossed off his third glass with unction. "Here's luck!" he cried, and Mr. Miller, who used spirits sparingly, and in the afternoon not at all, was forced to include himself in the aspiration with the good fellowship which is implied in a courteous bow. At half-past nine Aylmer's soldier servant found, as Landon had prophesied, nothing extraordinary in his master's guest's return. The glint of a second half crown shone persuasively in that guest's hand as he expressed his desire to write a note to await the master's coming. He was shown without any demur into the sitting-room, and supplied with pen and paper. But Landon's talents were not wasted on literary composition when he was left alone. He produced a pair of pliers and dealt very drastically with the padlock on the bookcase, opened the glazed doors, and ran his fingers down the numbers engraved upon the morocco-bound volumes. He selected one, opened it, flipped the pages, and finally came to a halt, his finger-tip poised above a plan. He closed the book and went to the window. He opened it noiselessly. "Number 34 North Front. Elevation of gun platforms with angles to east and south," he enunciated very quietly but very distinctly into the night. A grayness stirred in the shadow below the window. There was a whispered reply. "Right!" answered Miller's voice laconically, and Landon poised the book in mid-air.