The captured Indian was made to accompany the train for two days and then was freed. The dog teams swept the party over the frozen trail at good speed toward the Anakturuk River which empties into the Coleville, which in turn reaches the Arctic Ocean at Nigatuck, in sight of the Thetis Islands. Food was very short. Game seemed to have fled from the valleys through which they passed. The cold at night (the only time they could travel) remained intense. And that flight toward the ocean shore--or what had once been that shore--was a perilous journey indeed. CHAPTER XXV THE HERD OF KADIAKS Jack Darrow and Mark Sampson had never experienced so arduous a trip by dog sled as this. The party was really running a race with starvation. The terrible frosts of each long night on this island in the air had killed every species of vegetation the country wide, save the very hardiest trees and shrubs. The country, which two weeks before had been verdant as only a northern country can be verdant in late summer, was now as black as though a fire had swept over it. Everywhere, too, lay the volcanic ashes that had fallen ere the new planet had been shot from the earth by the volcanic eruption. It was indeed a devastated country through which the Alaskan dogs drew them. They dared not drive the dogs more than twelve hours out of the long night; but when the word was given to "mush," and the train started, the party kept up a good speed for those dozen hours. Andy Sudds and Phineas Roebach took the lead in this journey. They understood better how to handle the dogs and how to choose the trail. But, indeed, the trail was pretty well marked for them by the white traders who had gone before. Their camping sites were marked by a plenitude of discarded and empty food tins. The party ahead, in whose pursuit the boys and their friends were, undoubtedly traveled just as fast as Jack and Mark. And they had a week's start, according to the Indian who had not been allowed to return to his fellows until the whites were well along the trail to the Anakturuk River. The valley of the river, when they reached it, was a desert. There was little wonder that most of the game had fled. All herb-eating animals would have died for want of forage. "I am not sure," the professor said, gravely, during one of their campfire talks, "that physical life of any kind can long exist in this small planet. The vegetation is being rapidly destroyed. Soon the ground will become like rock. The carnivorous beasts will live for a while on the more timid creatures, then they will fight among themselves until the last beast is destroyed. "There were no great lakes in this Alaskan region when our present planet was a part of the earth. We do not know how full the streams may be of fish. There are few birds to be seen, that is sure. I fear that before many years this will be either a dead and frozen island floating in space, or it will be absorbed by some other body of the universe."