Never did the mustangs get enough to eat. Another sort of madness than the madness for liberty was laying hold of Sam. His days consisted of timid attempts at grazing, from which he would start at the lightest sound; of enforced pilgrimages from one pasture to another; and it must have been four hundred hours since he had had his fill of water. More than once, in a frenzy of revolt, he put five miles between him and his clinging disturber; but after two hours of uneasy nibbling he would be interrupted once again--and again must move on. What food he got failed to nourish as it should, and the rest he snatched was not rest. In the night, when he might have lost his foe, the mule knew well that he was near, for there in the blackness his fire sent up its sparks and it drew him and his companions like a magnet. No matter where they roamed, the cook managed to spend the dark hours near water, and the band could not tear themselves from the vicinity. There came a day when Sam’s ribs showed pitifully through his rough coat and he shuffled along in desperate dejection, his ears flopping. A heavy fatigue numbed his limbs, made cruel weights of them, and he was thirsty, deliriously thirsty; but if his plight was bad, that of the mustangs was worse. They stumbled coughing through the dust, too tired to lift their feet. Occasionally one broke into a half-hearted trot which survived only a few steps. The race was run. Within six hours the band began to break up. First the mares and colts dropped out, careless of what might befall. The mothers went weakly to feeding on the burnt grass, their offspring hovering near in the last stages of exhaustion; but to these Dave paid no attention. He was after Hell-on-Wheels, and he did not intend to inject new life into the jaded survivors by the slaughter of their beaten companions. By his orders Charlie, too, ignored them, though his fingers itched as his mind dwelt on the reward. Four of the horses lagged, staggered forward a few paces and fell behind, spent, swaying dizzily as they moved aside to let Dave pass. They were oblivious to everything now, insensible to peril, scarcely able to discern objects through their glazed eyes; but Sam and the stallion and some few kept on. Dave followed. Hot rebellion surged up in the mule more than once, sapping his last ounce of spirit. Up would go his head in defiance and he would increase his lead; but the strength was ebbing from the wonderful muscles of him; he was sick at heart and wanted to lie down. Ahead, perhaps an hour’s walk, he knew there was water. He must reach that. Would this thing that hung to their rear never give them respite? Dave trudged now only twenty yards back. He was footsore, a fearful weariness was upon him and the heat was awful. Yet no thought of giving up occurred to his mind; his patience was unfailing. Not once did he do a hurried thing to alarm the quarry. [Illustration: “_What you mean by running off this a-way?_”]