The twilight would struggle with the night for another two hours. Then it would be intensely dark, for the sky was cloudy, and there would be no moon. This gloom would favor the plans of Ivan Ogareff.

For a few days already a sharp frost had given warning of the approaching rigor of the Siberian winter, and this evening it was especially severe. The Russians posted by the bank of the Angara, obliged to conceal their position, lighted no fires. They suffered cruelly from the low temperature. A few feet below them, the ice in large masses drifted down the current. All day these masses had been seen passing rapidly between the two banks.

This had been considered by the Grand Duke and his officers as fortunate. Should the channel of the Angara continue to be thus obstructed, the passage must be impracticable. The Tartars could use neither rafts nor boats. As to their crossing the river on the ice, that was not possible. The newly-frozen plain could not bear the weight of an assaulting column.

This circumstance, as it appeared favorable to the defenders of Irkutsk, Ogareff might have regretted. He did not do so, however. The traitor knew well that the Tartars would not try to pass the Angara, and that, on its side at least, their attempt was only a feint.

About ten in the evening, the state of the river sensibly improved, to the great surprise of the besieged and still more to their disadvantage. The passage till then impracticable, became all at once possible. The bed of the Angara was clear. The blocks of ice, which had for some days drifted past in large numbers, disappeared down the current, and five or six only now occupied the space between the banks. The Russian officers reported this change in the river to the Grand Duke. They suggested that it was probably caused by the circumstance that in some narrower part of the Angara, the blocks had accumulated so as to form a barrier.

We know this was the case. The passage of the Angara was thus open to the besiegers. There was great reason for the Russians to be on their guard.

Up to midnight nothing had occurred. On the Eastern side, beyond the Bolchaia Gate, all was quiet. Not a glimmer was seen in the dense forest, which appeared confounded on the horizon with the masses of clouds hanging low down in the sky. Lights flitting to and fro in the Angara camp, showed that a considerable movement was taking place. From a verst above and below the point where the scarp met the river's bank, came a dull murmur, proving that the Tartars were on foot, expecting some signal. An hour passed. Nothing new.

The bell of the Irkutsk cathedral was about to strike two o'clock in the morning, and not a movement amongst the besiegers had yet shown that they were about to commence the assault. The Grand Duke and his officers began to suspect that they had been mistaken. Had it really been the Tartars' plan to surprise the town? The preceding nights had not been nearly so quiet--musketry rattling from the outposts, shells whistling through the air; and this time, nothing. The officers waited, ready to give their orders, according to circumstances.

We have said that Ogareff occupied a room in the palace. It was a large chamber on the ground floor, its windows opening on a side terrace. By taking a few steps along this terrace, a view of the river could be obtained.

Profound darkness reigned in the room. Ogareff stood by a window, awaiting the hour to act. The signal, of course, could come from him, alone. This signal once given, when the greater part of the defenders of Irkutsk would be summoned to the points openly attacked, his plan was to leave the palace and hurry to the Bolchaia Gate. If it was unguarded, he would open it; or at least he would direct the overwhelming mass of its assailants against the few defenders.

He now crouched in the shadow, like a wild beast ready to spring on its prey. A few minutes before two o'clock, the Grand Duke desired that Michael Strogoff--which was the only name they could give to Ivan Ogareff--should be brought to him. An aide-de-camp came to the room, the door of which was closed. He called.