Left alone with the dead men, Dick set immediately about what he thought was his duty. Upon closer inspection he found that the men had not really frozen to death as he had at first supposed, but that one, or both, of them had died from injuries received from a bad fall.
The body near the sledge was partially wedged under one of the runners. The sledge itself was crushed and splintered in front beyond repair. Dick gazed up at the edge of the walls forming the amphitheater, picturing in his mind what he thought had happened. This is what he imagined:
Two men, sledging over an uncharted land in the teeth of a blinding blizzard. An ineffectual struggle of dog and man to avoid slipping into an abyss which they sensed. Then the crash of the sledge and bodies at the foot of the bank. One man had died immediately, crushed by the fall and the sledge. The other had lived to crawl away and lean up against the rock wall which he had never quitted. It was one of the countless tragedies of the north, one of the secrets of the mysterious disappearance of men who had braved the Arctic and never returned.
Dick inspected every foot of ground near the sledge and found the remains of their dogs. But nowhere could he find any record or memoranda as to who the men were and what had been their mission.
He was about to examine the ice-crusted dunnage in the wrecked sledge when Sandy came running in calling to him.
“Someone’s in the cave! I believe Mistak has trailed us after all!”
Dick hastily quitted his work at the sledge and ran back into the cave after Sandy. When they reached the point where they had plugged up the passage, their worst fears were realized. Someone was trying to break in, and the mumble of voices came faintly to their ears. The boys had underestimated the trail-craft of the white Eskimo and his men.
“Mistak has discovered our hiding place in spite of all the pains we took to cover our tracks,” Dick spoke disappointedly. “All we can do now is keep them out by adding to this barricade. We can rebuild it faster than they can break it down, because on the other side only one can work at a time. Let’s get to work, Sandy.”
All the loose boulders and fragments of ice the boys could find they brought to the barricade and piled there as fast as possible. But they soon found that their enemies were gaining on them. This was not noticeable until the boys had used up all the boulders near them and were required to run all the way to the amphitheater for more material. Also, as Mistak’s men worked their way further in, the cave became larger and the outlaws could work more freely. Added to this, Dick’s and Sandy’s job of filling the passage became bigger and bigger the further back they retreated.
“We’ll never keep them out!” Sandy panted at last. “I guess this is our last adventure, Dick.”