“Maybe it was your imagination.”

But what happened next assured Sandy that Dick had not been using his imagination. A dark form heaved up out of the water almost under Sipsa’s ice pole. The umiack rocked dangerously and nearly upset the Eskimo. The boys got a clear look at the walrus this time for just a moment as the huge creature reared out of the water and looked at them before it sunk out of sight in a whirlpool of bubbles.

Sandy snatched up his rifle, but Dick warned him to hold fire until it was absolutely necessary.

“Was that the walrus?” called Corporal McCarthy backing water with his paddle.

“You bet it was,” Dick shouted, “and if he’d been two feet nearer he’d have turned us over—hey!”

Dick said no more for at that instant the umiack, with its heavy load, was hoisted upward out of the water from the impact of a powerful body underneath. Sipsa tumbled backward from the prow, falling in among the whimpering dogs. Sandy and Dick clung to their seats while the boat dropped back to the water with a heave and splash. Fortunately, the umiack settled to an even keel without taking in too much water. But scarcely had they recovered from the nearly disastrous effects of the walrus’s first attack, when Sipsa shouted a warning from the stern.

“There he is again—coming at us from the front!” shouted Sandy, throwing up his rifle as Dick snatched up his own.

As Dick took aim at the rushing mass of fur, tusks, and flippers, he saw Corporal McCarthy level his rifle from the kayack. The three rifles boomed almost as one. The walrus, hit hard, swerved and rolled in his mad attack, and in a whirl of water sank out of sight, leaving a red blot in the water behind him.

“He’s been wounded badly, if not killed,” said Sandy pointing at the blood in the water.

“I hope he’ll leave us alone anyway, but if he don’t——” Dick tightened his grip on his rifle.