The garrison of Omsk, reduced to two thousand men, resisted valiantly. But driven back, little by little, from the mercantile portion of the place, they were compelled to take refuge in the upper town. It was there that the Governor-General, his officers, and soldiers had entrenched themselves. They had made the upper quarter of Omsk a kind of citadel, and hitherto they held out well in this species of improvised “kreml,” but without much hope of the promised succor. The Tartar troops, who were descending the Irtych, received every day fresh reinforcements, and, what was more serious, they were led by an officer, a traitor to his country, but a man of much note, and of an audacity equal to any emergency. This man was Colonel Ivan Ogareff. Ivan Ogareff, terrible as any of the most savage Tartar chieftains, was an educated soldier. Possessing on his mother’s side some Mongolian blood, he delighted in deceptive strategy and ambuscades, stopping short of nothing when he desired to fathom some secret or to set some trap. Deceitful by nature, he willingly had recourse to the vilest trickery; lying when occasion demanded, excelling in the adoption of all disguises and in every species of deception. Further, he was cruel, and had even acted as an executioner. Feofar-Khan possessed in him a lieutenant well capable of seconding his designs in this savage war. When Michael Strogoff arrived on the banks of the Irtych, Ivan Ogareff was already master of Omsk, and was pressing the siege of the upper quarter of the town all the more eagerly because he must hasten to Tomsk, where the main body of the Tartar army was concentrated. Tomsk, in fact, had been taken by Feofar-Khan some days previously, and it was thence that the invaders, masters of Central Siberia, were to march upon Irkutsk. Irkutsk was the real object of Ivan Ogareff. The plan of the traitor was to reach the Grand Duke under a false name, to gain his confidence, and to deliver into Tartar hands the town and the Grand Duke himself. With such a town, and such a hostage, all Asiatic Siberia must necessarily fall into the hands of the invaders. Now it was known that the Czar was acquainted with this conspiracy, and that it was for the purpose of baffling it that a courier had been intrusted with the important warning. Hence, therefore, the very stringent instructions which had been given to the young courier to pass incognito through the invaded district. This mission he had so far faithfully performed, but now could he carry it to a successful completion? The blow which had struck Michael Strogoff was not mortal. By swimming in a manner by which he had effectually concealed himself, he had reached the right bank, where he fell exhausted among the bushes.