Then the sturdy engine quit. First a tortured grinding of clogged cylinders, puny explosions from the exhaust, a bucking and quivering. After that sudden stoppage of movement as if the car had plumped into a stone wall. The Doc and Guadalupe tumbled out of the seat and crawled beneath the car for protection. A stab of fear shot down through Stooder’s disordered thoughts--the water! None in the canteens, for they had drained the last into the radiator before starting from the treasure ground. Was there--could the sand have--? He inched himself through a new sand drift below the front axle to where the drain cock projected below the radiator base. Like a suckling kid he lifted his lips to the steel teat and turned the cock. A trickle of heavy mud filled his mouth with grit, then stopped. Radiator a mess of mud--cylinders clogged--feed pipes all choked and water--gone! Doc Stooder pulled his floppy hat over his face and whimpered the name of God. And on the back trail where the bell of the Lost Mission had been found; over that site which the Doc had so carefully mapped and measured the wind scoured and builded--scoured and builded. Obliterating, changing, re-creating. CHAPTER XIX THIRST The sun went down before the sand storm abated. Two men, the one called civilized, the other a savage, crouched like rabbits in a covert beneath the body of the little car with a high sand drift piled up to windward even over the radiator top. Two mites in the wind-scourged wilderness of Altar with love o’ life the leveller that made them kin. When the last vagrant wind fury had passed fell silence almost terrific by contrast with the uproar of the storm. In place of the slithering and whistling of driven sand an oppressive stillness, which seemed dropped from the void of the stars, now showing. Occasionally the dry rustle of sand dropping in rivulets from some desert bush lifting its head after the scourging; that was all. When the two crawled out from beneath their shelter Guadalupe was for an immediate start afoot in the direction of the faint pencilings of red marking the west. But Doc Stooder possessed an abiding glimmer of faith in the soundness of the car and insisted on taking stock of its motive possibilities. A cursory examination convinced him of the hopelessness of his trust, for the sand was heaped entirely over the unprotected engine--desert cars dispense with a hood because it blankets the engine’s heat--and he knew that even with water in the radiator he couldn’t get a kick out of the thing before a thorough overhauling. This was out of the question. They must achieve their escape from the desert’s trap afoot.