Mirai Khan made a decisive, guttural denial. "Not so. It is the will of Allah that moves the sands. Once there was a city that sinned----" "And a holy mullah." Gray recalled the legend Delabar had related on the steamer. "He alone escaped the dust that fell from the sky. It was long ago. So that is your _liu sha_!" The hunter's slant eyes widened in astonishment. "By the beard of my father! Are you a reader of the Koran, to know such things as this? Aye, it is so. The _liu sha_ came because of a sin, and without doubt that is why the place is still inhabited of a plague. The Chinese priests bring men there--men who are already in the shadow of death." "Then, Mirai Khan, there must be a city or an encampment, if many men live there." "I have not seen it. Nor have those who talked to me." "But you have not been there?" "How should I--seeing that the place is inhabited of a sin? No Mohammedan will go there." "What manner of sickness is this--the pale plague?" "I know not. But for many miles, aye, the space of a week's ride, no men will bring their _yurts_ for fear of it." Gray gave it up with a shrug. The Kirghiz was speaking riddles, twisted recollections of legends, and tales doubtless exaggerated. While Mirai Khan snored away comfortably, the American went over what he had said in his mind. The night had grown cold, and he threw the last of the wood on the fire, tucking his blanket about his feet. Their camp was utterly silent, except for the occasional splutter of the flames. Mirai Khan had said positively that he had seen no city in the Gobi where Gray was bound, nor heard of one. The American knew that if buildings existed on the immense plain of the Gobi they would be visible for miles around. Even if the comrades of Mirai Khan had kept away from the place which they considered unhealthy, they would have sighted the buildings, at one time or another. Yet Brent had declared that he saw the summits of towers. Imagination, perhaps. Although missionaries were not as a rule inclined to fancies. Here was one contradiction. Then there were the _liu sha_. Mere legend, doubtless. Central Asia was rife with tales of former greatness. But one thing was clear. The Chinese priests came to this spot in the desert. And the legend of the plague might be framed to keep the Mohammedans away from the place. Since the late rebellion Mohammedan and Chinese had frequently taken up arms against each other--they had never been on friendly terms. Evidently the Buddhists, for some reason, took pains to keep this part of the desert to themselves. They even guarded it against intrusion--as Brent had discovered. And Brent had died of sickness. What was the pale sickness? Were men inflicted with it brought to the Gobi--the dreariest stretch of land on the surface of the earth?