The volcano's top had been stripped clean by the winds of countless years. Rocks, black, brown, even blood-red, were naked to the pitiless glare of the sun. Their colors were mingled in a weird fantasy of twisted lines that told of the inferno of heat in which they had been formed. They towered high above the head of Dean Rawson as he stood, panting and trembling with exhaustion. The cleft before him had become enormous: it was a canyon, half filled with pumice and coarse ash. * * * * * Rawson stood for long minutes in quiet listening. At the canyon's end would lie the crater, and in that crater he would find.... But there was no slightest picture in his mind of what he might see. He knew only that he himself must remain unseen. He went forward cautiously. Rocky walls; a floor of sand where his feet left no mark. He was watching ahead and above him. His gun was ready in his hand; he did not propose to be ambushed. He moved with never a sound. The silence persisted; no living thing other than himself lent any flicker of motion to the scene. Not even a lizard could hope for existence amid these dead and barren heights. He was alone--the certainty of it had driven deeply into his mind before the canyon end was reached. And, desert man though he was and accustomed to traveling the waste places of the earth, Rawson learned a new meaning and depth of solitude. Here was no voiceless companionship of trees or brush or cactus; no little living things scuttled across the rocks--he was alone, the only speck of life in a place where life seemed forbidden. So sure of this was he that he stepped boldly from the canyon's end. He knew before he looked that he would see only more of the same desolation. And his mind was filled equally with anger and disappointment. * * * * * Something was opposing him! Something had come into their camp--had killed old Riley. And he, Rawson, had been so sure he would find traces here that would allow him to give that opposing force a name.... He stared out from the rocky cleft into a sun-blasted pit. Already the rising sun was pouring its energy ever the jagged rim of bleak rocks and down into the vast throat, choked and filled with ash. It sloped gently from all sides, the gray-brown powder that had been coughed from within the earth. It made a floor where Rawson could have walked with safety. But he did not go on. "Damn it!" he said with sudden savagery. "What a fool I was to think of finding anyone here. Who would ever pick out a spot like this for a base of operations?"