This was the cause of the accumulation of ice, which became gradually soldered together, under the double influence of the increased pressure and of the cold. Five hundred feet beyond, the river widened again, and the blocks, gradually detaching themselves from the floe, continued to drift towards Irkutsk. It was probable that had the banks not narrowed, the barrier would not have formed.
But the misfortune was irreparable, and the fugitives must give up all hope of attaining their object.
Had they possessed the tools usually employed by whalers to cut channels through the ice-fields--had they been able to get through to where the river widened--they might have been saved.
But they had nothing which could make the least incision in the ice, hard as granite in the excessive frost.
What were they to do?
At that moment several shots on the right bank startled the unhappy fugitives. A shower of balls fell on the raft.
The devoted passengers had been seen. Immediately afterwards shots were heard fired from the left bank. The fugitives, taken between two fires, became the mark of the Tartar sharpshooters.
Several were wounded, although in the darkness it was only by chance that they were hit.
"Come, Nadia," whispered Michael in the girl's ear.
Without making a single remark, "ready for anything,"Nadia took Michael's hand.
"We must cross the barrier," he said in a low tone.
"Guide me, but let no one see us leave the raft."Nadia obeyed. Michael and she glided rapidly over the floe in the obscurity, only broken now and again by the flashes from the muskets. Nadia crept along in front of Michael. The shot fell around them like a tempest of hail, and pattered on the ice.
Their hands were soon covered with blood from the sharp and rugged ice over which they clambered, but still on they went.
In ten minutes, the other side of the barrier was reached.
There the waters of the Angara again flowed freely.
Several pieces of ice, detached gradually from the floe, were swept along in the current down towards the town.
Nadia guessed what Michael wished to attempt. One of the blocks was only held on by a narrow strip.
"Come," said Nadia. And the two crouched on the piece of ice, which their weight detached from the floe.
It began to drift. The river widened, the way was open.
Michael and Nadia heard the shots, the cries of distress, the yells of the Tartars. Then, little by little, the sounds of agony and of ferocious joy grew faint in the distance.
"Our poor companions!" murmured Nadia.
For half an hour the current hurried along the block of ice which bore Michael and Nadia. They feared every moment that it would give way beneath them. Swept along in the middle of the current, it was unnecessary to give it an oblique direction until they drew near the quays of Irkutsk. Michael, his teeth tight set, his ear on the strain, did not utter a word. Never had he been so near his object.
He felt that he was about to attain it!
Towards two in the morning a double row of lights glittered on the dark horizon in which were confounded the two banks of the Angara. On the right hand were the lights of Irkutsk;on the left, the fires of the Tartar camp.
Michael Strogoff was not more than half a verst from the town.
"At last!" he murmured.
But suddenly Nadia uttered a cry.
At the cry Michael stood up on the ice, which was wavering.
His hand was extended up the Angara. His face, on which a bluish light cast a peculiar hue, became almost fearful to look at, and then, as if his eyes had been opened to the bright blaze spreading across the river, "Ah!" he exclaimed, "then Heaven itself is against us!"