In Leeds they had, we know, mapped out the whole water-supply, as Barker had done at North Shields; and again in Sheffield, the plans of which were in Berlin; but fortunately we had discovered them at work in London, and had been able to prevent them from accomplishing their object. Two of the men had returned to Germany on being detected, and the other two were now at Devonport, where I had been living for a month in irritating inactivity. One afternoon, on receipt of a telegram from Ray, I immediately returned to London, and as I entered the flat in Bruton Street, my friend said: "The great _agent provocateur_ of the German Government, our friend Hermann Hartmann, has left for Russia, Jack. His employers have sent him there for some special reason. Would it not be wise for you to follow, and ascertain the latest move?" "If you think so, I'll go," I said readily. "You can take my place down at Devonport. I've been there too long and may be spotted. Where has Hartmann gone?" "First back to Berlin. He has been ordered to go to Poland on a special mission." "Then I must pick him up in Berlin," I said. And thus it was arranged. Next morning I obtained a special _visa_ to my passport from the Russian Ambassador, whom I chanced to know personally, and at 2.20 left Charing Cross for Calais, bound for Berlin. I was puzzled why Hartmann, the most trusted agent of the Kaiser's secret police, should be so suddenly transferred to Russian territory. It was only temporarily, no doubt, but it behoved us to have knowledge of what might be in the wind. It was winter, and the journey to the German capital was cold and cheerless. Yet I had not been there six hours before I had discovered that Hartmann had left for a place called Ostrog, in Eastern Poland. Therefore I lost no time in setting forth for that rather obscure place. Yes, nowadays my life was a strange one, full of romance and constant change, of excitement--and sometimes of insecurity. For what reason had the great Hartmann been sent so far afield? On leaving the railway, I travelled for two days in a sleigh over those endless snow-covered roads and dark forests, until my horses, with their jingling bells, pulled up before a small inn on the outskirts of the dismal-looking town of Ostrog. The place, with its roofs covered with freshly-fallen snow, lay upon the slight slope of a low hill, beneath which wound the Wilija Goryn, now frozen so hard that the bridge was hardly ever used. It was January, and that month in Poland is always a cold one.