They discovered that the mockers had living quarters in both the cool caves and the ones warmed by the hot springs. There was evidence that they hibernated during the winters in the warm caves.
There were no minerals in the mockers’ valley and they set out to continue their circuit of the chasm. They did not get far until the heat had become so great that the chasm’s tributaries began going dry. They turned back then, to wait in the little valley until the fall rains came.
When the long summer was ended by the first rain they resumed their journey. They took a supply of the orange corn and two of the mockers; the yellow one and its mate. The other mockers watched them leave, standing silent and solemn in front of their caves as though they feared they might never see their two fellows or the humans again.
The two mockers were pleasant company, riding on their shoulders and chattering any nonsense that came to mind. And sometimes saying things that were not at all nonsense, making Humbolt wonder if mockers could partly read human minds and dimly understand the meaning of some of the things they said.
They found a place where saltpeter was very thinly and erratically distributed. They scraped off all the films of it that were visible and procured a small amount. They completed their circuit and reached the foot of the long, steep slope of the Craigs without finding anything more.
It was an awesome climb that lay before them; up a grade so steep and barred with so many low ledges that when their legs refused to carry them farther they crawled. The heat was still very serious and there would be no water until they came to the spring beyond the mountain’s summit. A burning wind, born on the blazing floor of the chasm, followed them up the mountain all day. Their leather canteens were almost dry when night came and they were no more than a third of the way to the top.
The mockers had become silent as the elevation increased and when they stopped for the night Humbolt saw that they would never live to cross the mountain. They were breathing fast, their hearts racing, as they tried to extract enough oxygen from the thin air. They drank a few drops of water but they would not touch the corn he offered them.
The white mocker died at midmorning the next day as they stopped for a rest. The yellow one crawled feebly to her side and died a few minutes later.
“So that’s that,” Humbolt said, looking down at them. “The only things on Ragnarok that ever trusted us and wanted to be our friends—and we killed them.”
They drank the last of their water and went on. They made dry camp that night and dreams of cold streams of water tormented their exhausted sleep. The next day was a hellish eternity in which they walked and fell and crawled and walked and fell again.
Barber weakened steadily, his breathing growing to a rattling panting. He spoke once that afternoon, to try to smile with dry, swollen lips and say between his panting gasps, “It would be hell—to have to die—so thirsty like this.”
After that he fell with increasing frequency, each time slower and weaker in getting up again. Half a mile short of the summit he fell for the last time. He tried to get up, failed, and tried to crawl. He failed at that, too, and collapsed face down in the rocky soil.
Humbolt went to him and said between his own labored intakes of breath, “Wait, Dan—I’ll go on—bring you back water.”
Barber raised himself with a great effort and looked up. “No use,” he said. “My heart—too much—”
He fell forward again and that time he was very still, his desperate panting no more.
It seemed to Humbolt that it was half a lifetime later that he finally reached the spring and the cold, clear water. He drank, the most ecstatic pleasure he had ever experienced in his life. Then the pleasure drained away as he seemed to see Dan Barber trying to smile and seemed to hear him say, “It would be hell—to have to die—so thirsty like this.”
He rested for two days before he was in condition to continue on his way. He reached the plateau and saw that the woods goats had been migrating south for some time. On the second morning he climbed up a gentle roll in the plain and met three unicorns face to face.
They charged at once, squealing with anticipation. Had he been equipped with an ordinary bow he would have been killed within seconds. But the automatic crossbow poured a rain of arrows into the faces of the unicorns that caused them to swing aside in pain and enraged astonishment. The moment they had swung enough to expose the area just behind their heads the arrows became fatal.
One unicorn escaped, three arrows bristling in its face. It watched him from a distance for a little while, squealing and shaking its head in baffled fury. Then it turned and disappeared over a swell in the plain, running like a deer.
He resumed his southward march, hurrying faster than before. The unicorn had headed north and that could be for but one purpose: to bring enough reinforcements to finish the job.
He reached the caves at night. No one was up but George Ord, working late in his combination workshop-laboratory.
George looked up at the sound of his entrance and saw that he was alone. “So Dan didn’t make it?” he asked.
“The chasm got him,” he answered. And then, wearily, “The chasm—we found the damned thing.”
“The red stratum—”
“It was only iron stains.”
“I made a little pilot smelter while you were gone,” George said. “I was hoping the red stratum would be ore. The other
