"I know what you mean--but, watch him next time one of those dust-devils comes by." The day before they had descended the northern slope of the high plateau onto the long, sandy plain that extended northward. Everywhere there were the dancing, careening dust-devils, tall columns of the brick-red sand; faintly menacing forms, pursuing some unseen purpose of their own. From time to time, one would swerve close, seeming to keep pace with them for a few steps before whirling off in its erratic dance. One approached them now. Rodriguez turned toward it making a furtive gesture with thumb and forefinger and deliberately trickled a stream from his water bottle upon the sand. Bradford came forward on the run, shouting into the hastily adjusted helmet mike. Angrily he jerked the bottle out of Rodriguez' unresisting hand. "What the hell do you think you're playing at?" Bradford panted. Rodriguez eyed him sullenly. "I know these things, as my people know them. Los _Bailerines del Diablo_--the devil-dancers. One gives them what is most precious. _Es muy necessario._" More and more he was losing his usually fluent, faintly accented English and reverting to his native tongue. Bradford eyed him sternly. "Rodriguez, you are a good Catholic. You wear a holy medal. What's all this talk about sacrifices to the devil?" Rodriguez' gaze slid away. "I don't think God knows about this place. This is of _El Diablo_." "So now you want to get in good with the Devil," Bradford grunted. "Well, you can do it some other way than with the last of the water." He jerked his head at Canham waiting wearily behind them. "Come on, you two. We'll all feel better when we get out of this--desert." He ended with a wry twist of the lips. He had nearly said 'god-forsaken.' Maybe Rodriguez had the right idea after all. * * * * * During the afternoon, some chance convection of air currents sharply increased the dust whirls. The desert seemed full of their erratic, spinning shapes. Rodriguez plodded along, ignoring Canham's sporadic attempts at conversation. The chilly sunlight was waning and Bradford's face lighted with relief at the sight of a small sand hill. At least they could dig a hole to get their backs into and break the whistling winds. He felt an irrational comfort at the thought of the coming darkness--at least they wouldn't be able to see the dust-devils. Maybe they could get some talk going and snap Rodriguez out of his melancholy silence. Perhaps they had all been getting too introverted since the series of disasters. They made camp before dark, digging themselves well in; Bradford and Canham forced themselves into a semblance of cheerfulness as they worked. Rodriguez's face remained dark and unsmiling. Like one of those damned stone images in the Yucatan jungle, Bradford thought with a brief burst of irritation. You wouldn't think that the little Mexican had been the ship's humorist, his face one perpetual white-toothed smile.