Such were the monsters which beset Polaris. All around the piece of ice on which he floated with the sledge the smaller drift was thrashed by their plunging bodies. Again and again they thrust their frightful snouts above the surface and strove to hurl themselves onto the ice cake. Some of them were more than twenty feet in length.

When the first hideous head appeared from the deep and nearly overturned his float Polaris stood as if frozen, staring at it in amazement. Such a thing he had never seen. He crouched on the ice and tightened his grip on his long spear. When he saw the number of his enemies he realized the futility of an attempt at battle with such weapons as he bore.

Immediately he became alert to outwit them. With his agility he might have essayed to cross the ice and elude them safely were he unhampered by the unwieldy sledge, but not for an instant did he consider abandoning it.

In a glance he picked out the next resting-spot, some feet distant across the drift. He pushed the sledge almost to the edge at one side of the cake, and sprang to the other side, halting on the brink and bracing himself, with his spear-blade dug deeply into the ice.

There was a rushing and thrashing of huge bodies as the killers piled over one another in their eagerness to reach their prey. Several frightful heads were thrust from the water, their dripping jaws snapping within a few feet of the intrepid man. Quick as light he dashed across the ice cake, snatched up the ends of the long harness, and crossed the drift to the next large fragment. Watching his chances, he yanked the sledge across to him.

A dozen times he repeated his tactics successfully and worked in near to shore. If he could accomplish his ruse once more he would win through; he would be above water so shallow that even the bold killers would not dare to follow him for fear of being stranded there. But nearer to the landing the drift had been ground finer, and there was not between him and the shore another large piece. There he made a stand and considered.

He heard the voice of the girl calling to him.

"Shoot!" she cried. "Shoot and wound one of them! If you maim it badly the others will turn and attack it. Then you can get away!"

Polaris tossed his arm in sign that he had heard, and drew from their holsters his brace of heavy revolvers. He had but an instant to wait. One of the savage killers reared his immense and ugly snout from the waters less than a rod away. Polaris fired both guns straight into the gaping jaws.

That was nearly his undoing, for so mighty a plunge did the scathed and frightened monster give that it shot nearly the whole of its ponderous body across the edge of the ice where the man stood and cracked the cake clean in two. Then it sank into the water, convulsively opening and closing its jaws, as if it would eject the stinging pellets which it had received. The water was dyed red around it.