In hot mid afternoon when the acrid, gray dust cloud kicked up by the listless plodding of eight thousand cloven hoofs formed the only blot on the hard blue above the Staked Plains, an ox stumbled and fell awkwardly under his yoke, and refused to scramble up when his negro driver shouted and prodded him with the end of a willow gad. -Call your master, Ezra,- directed a quiet woman voice gone weary and toneless with the heat and two restless children. -Don't beat the poor brute. He can't go any farther and carry the yoke, much less pull the wagon.- Ezra dropped the gad and stepped upon the wagon tongue where he might squint into the dust cloud and decide which gray, plodding horseman alongside the