"Of course I said nothing about your business; but while I was talking with the Scotland Yard man a letter was left by a messenger, addressed to Mirsky. The letter will be examined, of course, by the proper authorities, but I was not a little interested to perceive that the envelope bore the Russian Imperial arms above the words, 'Russian Embassy.' Now, why should Mirsky communicate with the Russian Embassy? Certainly not to let the officials know that he was carrying on a very extensive and lucrative business in the manufacture of spurious Russian notes. I think it is rather more than possible that he wrote--probably before he actually got your drawings--to say that he could sell information of the highest importance, and that this letter was a reply. Further, I think it quite possible that, when I asked for him by his Russian name and spoke of 'a confidential letter,' he at once concluded that _I_ had come from the Embassy in answer to his letter. That would account for his addressing me in Russian through the keyhole; and, of course, an official from the Russian Embassy would be the very last person in the world whom he would like to observe any indications of his little etching experiments. But anyhow, be that as it may," Hewitt concluded, "your drawings are safe now, and if once Mirsky is caught--and I think it likely, for a man in his shirt-sleeves, with scarcely any start and, perhaps, no money about him, hasn't a great chance to get away--if he is caught, I say, he will probably get something handsome at St. Petersburg in the way of imprisonment, or Siberia, or what-not; so that you will be amply avenged." "Yes, but I don't at all understand this business of the drawings even now. How in the world were they taken out of the place, and how in the world did you find it out?"