Heedless of the blood spurting from the wound in the side of Ashton's head, Blake snatched up the automatic rifle and fired at a point between two knobs of rock on the hill crest. Promptly a hat appeared, then an arm and a rifle. It might have been expected that a bullet would have instantly followed; yet the assassin was strangely deliberate about getting his aim. Blake did not wait for him. He began to fire as fast as the automatic ejector and reloader set the rifle trigger. Three bullets sped up at the assassin before he had time to drop back out of sight. Blake started up the hillside, his pale eyes like white-hot steel. He was in a fury, but it was the cold fury of a man too courageous for reckless bravado. He went up the hill as an Apache would have charged, dodging from cover to cover and, wherever possible, keeping in line with a rock or tree in his successive rushes. At every brief stop he scanned the ridge crest for a sign of his enemy. But the assassin did not show himself. For all that Blake could tell, he might be waiting for a sure shot, or he might be lying with a bullet through his brain. To avoid suicidal exposure, the engineer was compelled to veer off to the right in his ascent. He reached the ridge crest without a shot having been fired at him. Leaping suddenly to his feet, he scrambled up to the flat top of a high crag, from which he could peer down upon the others. The natural embrazure from which the assassin had fired was exposed to his view; but the place was empty. He looked cautiously about at the many huge bowlders behind which a hundred men might have been crouching unseen by him, advantageous as was his position. To flush the assassin would require a bold rush over and around the rocks. Blake set his powerful jaw and gathered himself together for the leap down from his crag. At that moment his alert eye caught a glimpse of a swiftly moving object on the mesa at the foot of the far side of the hill. It was a horse and rider racing out of sight around the bend of a ridge point. Blake whipped the rifle to his shoulder. But the cowardly fugitive had disappeared. He lowered the rifle and started back down the hill faster than he had come up. Leaping like a goat, sliding, rushing--he raced to the bottom in a direct line for Ashton. The victim lay as he had fallen, his head ghastly red with blood, which was still oozing from his wound. Blake dropped down beside the flaccid body and tore open the front of the silk shirt. He thrust in his hand. For some moments he was baffled by the violent throbbing of his own pulse. Then, at last, he detected a heartbeat, very feeble and slow yet unmistakable. He turned Ashton on his side, and washing away the blood with water from the canteen, examined the wound with utmost carefulness. The bullet had pierced the scalp and plowed a furrow down along the side of the skull, grazing but not penetrating the bone.