Once they had thought about going to the valley in the chasm where the mockers would be hibernating in their warm caves. But even if they could have gone up the plateau and performed the incredible feat of crossing the glacier-covered, blizzard-ripped Craigs, they would have found no food in the mockers' valley--only a little corn the mockers had stored away, which would soon have been exhausted. There was no place for them to live but in the caves or as nomads migrating with the animals. And if they migrated to the equator each year they would have to leave behind them all the books and tools and everything that might someday have given them a civilized way of life and might someday have shown them how to escape from their prison. He looked again to the south where the halo should be, thinking: _They should have made their decision in there by now. I'm their leader--but I can't force them to stay here against their will. I could only ask them to consider what it would mean if we left here._ Snow creaked underfoot as he moved restlessly. He saw something lying under the blanket of frost and went to it. It was an arrow that someone had dropped. He picked it up, carefully, because the intense cold had made the shaft as brittle as glass. It would regain its normal strength when taken into the caves---- There was the sound of steps and Fred Schroeder came out of the tunnel, dressed as he was dressed in bulky furs. Schroeder looked to the south and said, "It seems to be starting to get a little lighter there." He saw that it was; a small, faint paling of the black sky. "They talked over what you and I told them," Schroeder said. "And about how we've struggled to stay here this long and how, even if the sun should stop drifting south this year, it will be years of ice and cold at the caves before Big Spring comes." "If we leave here the glacier will cover the caves and fill them with ice," he said. "All we ever had will be buried back in there and all we'll have left will be our bows and arrows and animal skins. We'll be taking a one-way road back into the stone age, for ourselves and our children and their children." "They know that," Schroeder said. "We both told them." He paused. They watched the sky to the south turn lighter. The northern lights flamed unnoticed behind them as the pale halo of the invisible sun slowly brightened to its maximum. Their faces were white with near-freezing then and they turned to go back into the caves. "They had made their decision," Schroeder went on. "I guess you and I did them an injustice when we thought they had lost their determination, when we thought they might want to hand their children a flint axe and say, 'Here--take this and let it be the symbol of all you are or all you will ever be.' "Their decision was unanimous--we'll stay for as long as it's possible for us to survive here." * * * * *