Sleep overtakes one suddenly and strangely at times. Without intending to even close one eye, Mark was off into dreamland with a promptness that was surprising. He settled back against the tree and slept standing up. But his neglected duty troubled his subconscious mind. He was uneasy. In his dreams he was troubled by nameless dread. He awoke at last seemingly with a scream of human agony in his ears.

Had something happened to his comrades during his brief defection? Mark sprang erect and looked over the sleeping camp. Every person was in his place, but the fire was low. It had been, perhaps, an imagined sound that aroused him so suddenly.

He threw more wood on the fire and stepped out upon the ice to get more of the fuel he had previously cut into handy lengths. This morainial deposit which offered rootage for the trees and bushes was but a narrow streak—a sort of an island on the glacier. They had carried the bear meat out to a small sink in the ice where there were great slabs of the hard crystal which were easily packed over the meat. As Mark started for the wood he heard a noise out on the ice in the direction of their cache. He picked up his rifle again quickly and started for the spot. Something was disturbing the meat, and Mark did not lack courage. His rifle was loaded and, thanks to Andy, he was a good shot. The old hunter took pride in training the boys to shoot well.

The youth did not stop to ask what manner of enemy it was disturbing their cache. And it never entered his head to disturb the camp. He ran right out upon the glacier and had advanced to within a few yards of the spot before he learned what he was up against, for a huge block of ice hid the cache from his view.

Around this ice-block, from either side, as though they had been waiting purposely to ambuscade him, shot several animals, who charged him without as much as a whine.

"Dogs!" thought Mark, remembering the Alaskans that Phineas Roebach had been forced to abandon. "They have gone mad."

But the next moment he saw his mistake. They were wolves—huge, gaunt, shaggy fellows, with gaping jaws displaying rows of ferocious teeth. They charged him in awful silence, their great claws scratching over the ice.

There were eight or ten of them in sight and they were only a few yards away from the youth when he first saw them. But instantly Mark dropped to one knee to steady himself, put the rifle to his shoulder, and opened fire.

Four shots he placed in quick succession. Two of the wolves rolled over and over upon the ice, and a third limped off after the remainder, who darted behind the ice-block again. Mark leaped up, uttering a shout of triumph, and followed them, believing that he had beaten the pack thus easily.

But the moment he came around the obstruction he found himself in the midst of the actual pack. He was not charged by a dozen of the fierce creatures, but by more than half a hundred.