Jeff Peters' empty blankets were still spread there on the sand, but no one had seen the big Negro since the camp turned in the night before. The expedition's daily travels under the blazing sun of the Mojave never had appealed particularly to Jeff, and he had apparently at last made good his repeated threats to desert. * * * * * The men were just getting up from breakfast when Layroh finished packing his tent and apparatus in his sedan, and started down toward the camp. As usual, he halted some five yards away from them, standing there for a moment in stony silence. Physically, the man was a giant, towering well over six feet in height. On several occasions when the expedition's cars had stalled in deep sand he had strikingly demonstrated the colossal strength in his tall body. His aquiline features, his red-bronze complexion, and his long black hair, were all suggestive of Incan or Mayan ancestry. No one had ever seen any trace of feeling or emotion upon his impassive features. Foster would have given a good deal for just one glimpse of the eyes hidden behind the dark-colored goggles. In their depths he might be able to find some reason for the tingling surge of nameless dread that Layroh's close approach always inspired. Layroh noted Jeff Peters' absence at once. "We seem to have our first deserter," he commented evenly. His voice was as richly resonant as the tone of some fine old violin. He hesitated almost imperceptibly between words, like one to whom English was not a native tongue. "It does not matter," he continued indifferently. "We can spare one man easily enough. To-day we shall continue toward the east. Pack the truck at once. We are ready to start." Without waiting for an answer, he turned and strode back to the sedan. A curious thought struck Foster as he stared after Layroh's retreating figure. What if the oddly distorted shadow he had seen against the tent wall last night had really been that of a man--had been that of Jeff Peters? * * * * * For only a moment did Foster mull over the idea. Then he promptly dismissed it as being absurd. He could imagine no possible reason for Jeff Peters being in Layroh's tent in the middle of the night. The shadow had been only remotely like that of a man, anyway. There had been neither head nor arms to the figure, only shapeless masses totally unlike anything human. They finished packing the breakfast stuff in the supply truck, and the party started out along the trail with Layroh's sedan leading the way. For nearly two hours they followed their usual routine, working steadily eastward and stopping at regular intervals while Layroh made his methodical tests with his instruments.