In a moment he had him down, and he struck once into Bruce's white face with his terrible knuckles. The blow sent a strange sickness through the younger man's frame; and he tried vainly to struggle to his feet. "Fight! Fight on!" was the message his mind dispatched along his nerves to his tortured muscles, but for an instant they wholly refused to respond. They had endured too much. Total unconsciousness hovered above him, ready to descend. Strangely, he seemed to know that Simon had crept from his body and was even now reaching some dreadful weapon that lay beside the dead form of the horse. In an instant he had it, and Bruce's eyes opened in time to see him swinging it aloft. It was his rifle, and Simon was aiming a murderous blow at him with its stock. There was no chance to ward it off. No human skull could withstand its shattering impact. Bruce saw the man's dark face with the murder madness upon it, the blazing eyes, the lips drawn back. The muscles contracted to deal the blow. But that war of life and death in the far reaches of Trail's End was not to end so soon. At that instant there was an amazing intervention. A great gray form came lunging out of the snow flurries. Their vision was limited to a few feet, and so fast the creature came, with such incredible, smashing power, that he was upon them in a breath. It was the Killer in the full glory of the charge; and he had caught up with them at last. Bruce saw only his great figure looming just over him. Simon, with amazing agility, leaped to one side just in time, then battered down the rifle stock with all his strength. But the blow was not meant for Bruce. It struck where aimed,--the great gray shoulder of the grizzly. Then, dimmed and half-obscured by the snow flurries, there began as strange a battle as the great pines above them had ever beheld. The Killer's rage was upon him, and the blow at the shoulder had arrested his charge for a moment only. Then he wheeled, a snarling, fighting monster with death for any living creature in the blow of his forearm, and lunged toward Simon again. It was the Killer at his grandest. The little eyes blazed, the neck hair bristled, he struck with forearms and jaws--lashing, lunging, recoiling--all the terrible might and fury of the wilderness centered and personified in his mighty form. Simon had no chance to shoot his rifle. In the instant that he would raise it those great claws and fangs would be upon him. He swung it as a club, striking again and again, dodging the sledge-hammer blows and springing aside in the second of the Killer's lunges. He was fighting for his life, and no eye could bemean that effort.