“Look here!” exclaimed Leslie. “Petrovitch must either have crossed or missed this crevasse somewhere. We’re converging upon the route which he took previous to our finding him. Why not ask him if he recognises any of the landmarks?”

In very halting, schoolboy French the lads questioned the stalwart Russian. Petrovitch replied that, so far as he was aware, he crossed no crevasse, but if the sleigh kept parallel with the dangerous stretch of ice for a few miles, he might be able to identify his former route.

“Let her rip, old man!” exclaimed Guy, as he took up his position at the steering wheel.

Almost at right angles to her previous course, the Bird of Freedom glided rapidly over the smooth, firm ice, Guy keeping a sharp look-out, especially towards the sinister, concealed crevasse on his left.

Suddenly Petrovitch grasped the lad by the shoulder.

“Here is our route!” he exclaimed. “I recognise that rock shaped like a dog’s head.”

“Then you must have crossed the crevasse without knowing it,” declared Guy. “See, it still continues in this direction.”

The Russian shrugged his shoulders.

“Perhaps,” he said. “But in any case it bore my weight, so what did it matter, then?”

“I’m afraid it matters now,” rejoined Guy. “It’s pretty evident that it won’t bear the weight of the sleigh and its crew. What do you propose?”

“We are not two versts from my companions’ temporary habitation,” said Petrovitch. “You have a rifle, I see. Why not fire a few shots to let them know we are close?”

“That won’t help us much,” objected Leslie, who, having stopped the motors, had joined in the council.

“If I could walk across, they can do the same,” declared the Russian. “Therefore, let us fire signal guns.”

Half a dozen rounds were fired at regular intervals, but no answering signal came from the direction of the wrecked airship. Petrovitch, nothing daunted at the failure of his plan, smiled broadly.

“Since they will not pay attention, I must needs go and bring them here,” he declared. And, without further delay, he commenced to place tins of concentrated food and biscuits into a small haversack.

“Unless harm befall me, I return in three hours,” he said.

“Guy, old man!” exclaimed his chum, “I can’t let that fellow toddle off by himself. I’m going with him. It’s not so very far, and the weather looks promising. The glass is steady, and the sun’s looking clearer than for days past; so here goes. You stand by and look after Mr. Ranworth.”

“All right,” assented Guy. “Only, mind and take care of yourself. I wish to goodness I was going with you.”

Upon Leslie broaching his decision to Petrovitch, the Russian objected. He felt quite capable of going alone, he declared; but Leslie was equally firm in his resolve.

Finally Petrovitch gave way, merely stipulating that they must be roped when crossing the crevasse, and that Leslie should lead.

“My young friend,” he explained, “if the ice should give way, you would fall. I, being great in size, could easily hold you, but if I went first and dropped into the crevasse you would not be able to save me; and, more, I would drag you after me. Is not that clear?”

Leslie nodded.

“Very good,” he assented. “I’ll go first.”

No doubt the ice bridge over the abyss had been hidden in snow when the two Russians passed over it on their dash for Desolation Inlet. The strong wind, following the blizzard before the snow had time to congeal, had uncovered the rotten ice and now revealed the danger.

Leslie advanced cautiously and with considerable fear. Even the fact that he was secured by a rope hardly minimised the sense of dread that the “ground” might give way under him with hardly any warning. He was seized by a momentary desire to retrace his steps, but realising that the Russian was following, and that he, an Englishman, had to “keep his end up,” the lad progressed steadily.

The scope of the rope was insufficient to bridge the entire crevasse. Long before Leslie gained the firm ice on the farther side, Petrovitch was crossing the treacherous belt.

Leslie recalled the Russian’s words. “If I dropped into the crevasse, you would not be able to save me; and, more, I would drag you after me.”

Just then Leslie felt the rope give. Turning his head, he saw that Petrovitch had cast off the life-line, and was lying full length upon the thin crust of ice.

“Hasten!” shouted the Russian. “The ice—it is cracking. If I go, tell my comrades I tried to do my duty.”

Leslie stood stock still. He had but another twenty yards to go to get clear of the dangerous ice-bridge, but the self-sacrificing spirit of his companion banished his own fears.

“Take hold of the rope again!” he exclaimed. “Lie down if you will. I will pull you across.”

“Agreed,” replied Petrovitch, but without attempting to pass the bowline over his shoulders, he contented himself by merely holding on with his hands.

The lad moved forward. With little difficulty the Russian’s huge bulk slid over the ice. Again there was an ominous creak. The strain on the rope was suddenly released, and, taken aback, Leslie slipped and fell flat on his face.

Quickly he regained his feet, fully expecting to find that his companion had vanished into that awful abyss. Petrovitch, too, had expected the catastrophe, and rather than put the English lad in any danger, he had released his hold on the rope without warning.

Leslie was safe now, but the rope had recoiled with the sudden relaxation of the strain, and the end was ten feet from the Russian.

With the ice creaking and groaning as he moved, Petrovitch crawled slowly towards the rope. Leslie could see the surface bending under his weight as he advanced inch by inch. The suspense was nerve-racking.

At length Petrovitch retrieved the rope. Leslie immediately walked away, hauling steadily the while, until the Russian was safely dragged to the firm ground on the other side of the chasm.

Spontaneously the English lad and the Russian giant held out their hands. Not a word was spoken, but the firm grip was a sufficient testimony to their appreciation of each other’s devotion.

The crevasse had been successfully crossed, but the disquieting fact remained that it now lay between them and the Bird of Freedom. If two persons had succeeded in crossing only by the skin of their teeth, how could twelve hope to negotiate that terrible ice-bridge?

On and on the pair trudged in silence, save for an occasional exchange of sentences in French. Presently the Russian unconsciously increased his pace. The wreck of the airship was in sight.

Its gaunt aluminium girders, twisted and bent almost out of recognition, completely dwarfed the large ice hut built a few feet from the wreckage. Above the hut floated the blue St. Andrew’s cross on a white ground—the Russian ensign.

Holding his gloved hands to his mouth in order to form a speaking trumpet, Petrovitch hailed.

Almost as soon as the sound reached the hut, men were observed to be pouring out like bees from a hive, and, in spite of the intervening distance, the rarefied atmosphere enabled them to maintain a lively conversation with their rejoicing comrade, while three or four of the stranded Russians hastened to meet their compatriot.

As they approached, Leslie could see that they were all tall, finely-built men, and apparently the picture of health. He could not help contrasting their appearance with that of the exhausted survivors of Claude Ranworth’s party and with that of Petrovitch and his companion, Dmitri, when rescued by the Bird of Freedom, According to Petrovitch’s account, he had left his comrades on the very verge of starvation.

Petrovitch lost no time in introducing Leslie to the newcomers, and, escorted by the latter, the lad was taken to the hut. Here the mystery of the fit appearance of the castaways was revealed, for roasting over an oil-stove which had been fashioned from material saved from the airship was a huge joint of bear’s flesh.

Very soon after the departure of Petrovitch and Dmitri, a polar bear had visited the camp. The Russians had thrown themselves upon it with their knives, and, after a brief struggle, the animal became the spoil of the victors.

After a good but hasty meal, preparations were made to abandon the wrecked airship and make for the Bird of Freedom.

An aluminium sleigh, also knocked together from the frame of the airship, was piled high with the men’s personal belongings and a few scientific instruments and records, while at Petrovitch’s suggestion two long lengths of rope were also taken.

There followed an animated discussion evidently with reference to the load on the sleigh. Petrovitch and two more seemed to be opposing the taking of so much luggage, but the rest insisted vehemently. Finally, the objectors lost the day.

With a meaning shrug of his broad shoulders, Petrovitch turned to Leslie.

“Wait till they arrive at the crevasse,” he said in a low tone.

It was downhill most of the way, and since there was no wind to impede them, the progress of the rescued party was well maintained. With relays of five men to pull the sleigh, that vehicle offered no drawback to their speed.

Suddenly, when they were within a quarter of a mile of the ice bridge, a rending crash was heard, and amid a shower of splintered ice a huge cavity appeared where a second previously an uninterrupted field of frozen snow hid the terrible chasm from view.

The newly-made hole was less than a hundred yards from the track by which Leslie and Petrovitch had passed. Undoubtedly the falling in of this part of the ice-bridge would seriously weaken the already none too secure route which had to be traversed before the Bird of Freedom was reached.

Leslie took no part in the operations that followed. He realised that the Russians knew what they were about, and that it would be unwise on his part to offer any suggestions.

Unloading the coils of rope from the sleigh, the men bent them to the rope which had already played such a good part in the previous crossing of the crevasse. The three lengths combined were sufficient to allow a double rope to stretch from one side to the other.

Securing the rope to the strongest part of the sleigh, Petrovitch prepared to cross. The 18-feet runners enabled his weight to be evenly distributed over a far greater extent than if he had adopted his previous expedient of crawling across the ice-bridge.

Having thrown overboard everything on the sleigh, the Russian wrenched off the centre strip of boarding on the floor. Then, sitting, he started to propel the sleigh across the ice, while his comrades paid out the rope as he went.

Although the surface sagged ominously, the hardy and courageous Russian completed his journey without mishap; then, assisted by Guy, who was anxiously awaiting the arrival of the party, he took his stand on the firm ground beyond, and passed the endless rope through his hands while his comrades hauled back the sleigh.

Leslie, by the unanimous decision of the Russians, was the next to cross. Lashed to the sleigh in case the ice-bridge should collapse, he was pulled across by Petrovitch, and on landing he, too, assisted in sending the empty sleigh back to the remainder of the party.

In this manner the crew of the wrecked airship crossed the crevasse until only one man was left. He was the one who took the lead in insisting on the baggage being taken with them. Reluctant to abandon the gear, he proceeded to reload the sleigh, in spite of the protests of his comrades.

With ten men trailing on the rope, his progress was an easy one until two-thirds of the way across. Then, without a creak to warn him, the ice suddenly gave way. His horrified comrades saw the luckless man make a frantic grasp at the framework of the sleigh. In his haste he gripped some of the baggage he had so foolishly insisted upon bringing across, and as the sleigh toppled and disappeared from view he was thrown clear of his only hope of safety.

Two minutes later the empty sleigh was hauled out of the ice-hole. The ill-starred passenger and all his baggage were lost for ever in the depths of the crevasse.