"Then how is it that some one is watching from up there? No excitement. I'm going to bid every one good night, then I'm going to investigate. When I leave you will quietly send men to all exits to the building. I want the man who sneezed, and I want him badly." Olga departed with Braine, only she immediately sought the taxi that brought her and was driven home. It was always understood that when any serious exploit was under way hereabouts she was to make her departure at once. Vroon stationed his men at the several exits and Braine went up-stairs. The man who had sneezed, however, had vanished as completely as if he had worn that invisible cloak one reads about in the Persian tales. As a matter of fact, after the second sneeze he had gone up to the roof, got out by the trap, and jumped--rather risky business, too--to the next roof and had clambered down the fire-escape of the second building. He was swearing inaudibly. After all these days of care and planning, after all his cleverness in locating the rendezvous of the Black Hundred, and now to lose his advantage because of an uncontrollable sneeze! He would never dare go back, and just when he was beginning to pick up fine bits of information! So Florence Hargreave was going to have a new father in a day or so? There were some clever rogues among this band of theirs; but their cleverness was well offset by an equal number of fools. Yes, there were some clever rogues, and to prove this assertion Braine secured a taxicab and drove furiously away, his destination the home of his ancient enemy. He dropped the cab a block or two away and presently stowed himself away in the summer house at the left of the lawn. It would have been a capital idea--that is, if the other man had not thought of and anticipated this very thing. So he used a public pay station telephone; and Braine waited in vain, waited till the lights in the Hargreave house went out one by one and it became wrapped in darkness within and moonshine without. Braine was a philosopher. He returned to his waiting taxicab, drove home, paid the bill, smiling grimly, and went to bed. It was going to be a wonderful game of blind man's buff, and it was going to be sport to watch this fool Paroff blunder into a pit.