His thirst for blood outstripped his fleet horse, who seemed to him, in his impetuous haste, to be creeping like a snail. He drove his spurs deep into the sides of the frightened animal, which almost leaped through his girth. A less expert horseman would have been unseated; but an earthquake could not have thrown this Centaur out of his saddle. The forests, hills and houses flowed past him like a river. Occasionally he halted an instant to inquire of some lonely traveler if he had seen a horse and buggy passing that way, but he was cunning enough to conceal his anxiety and to hide his joy as every answer made him more certain that he was on the trail of the fugitives. The road was perfectly familiar. He had traversed it a hundred times, and not having to inquire the way he had only to remember and to reflect. An undercurrent of speculation had been flowing through his mind as to where he should overtake the fugitives. "They will have arrived almost at the edge of the great forest and I will let them enter," he said to himself. Having reached the foot of a long hill, he dismounted, led his horse to a little brook and permitted him to drink. When the noble animal had quenched his thirst, the quack patted his neck, picked him a little wisp of grass and talked to him as if he were a man. "We will rest ourselves a little now, for we shall need all our strength and nerve. One more b-b-burst of speed and we shall overhaul them. Have you got your wind, Romeo? Come then, let us be off!" Once more he sprang into the saddle, the restive horse pawing the ground and leaping forward before he was seated. His master held him back while they ascended the long slope of the hill, and stopped him as they gained its summit. The descent was a gradual one, down into a beautiful valley. For a mile or two the road was perfectly straight and the rider, shading his eyes, glanced along it. In the distance a moving object attracted his attention, and as he gazed at it, long and strainingly, the terrible smile once more wreathed his white lips. He opened the holsters, drew out the pistols, examined them carefully, replaced them, felt of the stirrup straps, tightened the girth, settled himself in the saddle and shouted "Go!" The command electrified the horse, and he dashed forward again faster than ever. As they tore down the slope of the hill, it occurred to the doctor that he had not formed any definite plan as to what he should do to Pepeeta! "Shall I kill her, also?" he asked himself. The thought sent a shudder through him and he instinctively pulled on the bridle.