The awful rage which rose in the heart of Ab as he saw what was happening is what can no more be described than one can tell what a tiger in the jungle thinks. He saw another--the other his friend--pursuing and intending to take what he wanted to be his and what had become to him more than all else in the world; more than much eating and the skins of things to keep him warm, more than a mammoth's tooth to carve, more than the glorious skin of the great cave tiger, the possession of which made a rude nobility, more than anything and all else! He leaped aside from the path. He knew well the other path upon which were running Oak and Lightfoot. He knew that he could intercept them, because, though the running was not so good, the distance to be covered was much less, for to him path running was a light matter. In the wood he ran as easily and leaped as well and attained a point almost as quickly as the beasts. There was a stress of effort and, as the shadows deepened, he burst in upon the cross path where he knew were the fleeing Lightfoot and following Oak. He had thought to head them off, but Ab was not the only man who was swift of foot in the cave country. They passed, almost as he bounded from the forest. He saw them close together not many yards ahead of him and, with a shout of rage, bent himself in swift and terrible pursuit again. It was all plain to Ab now as he flew along, unnoted by the two ahead of him. He knew that Oak had, like him, determined to own Lightfoot, and had like him, been seeking her. Only chance had made the chase thus cross Oak's path; but that made no difference. There must be a grim meeting soon. Ab could see that the endurance of the wonderfully fleet-footed woman was not equal to that of the man so near her. She would soon be overtaken. Before her rose the hill, not a mile in its slope, where were her father's cave, and safety. He knew that she had not the strength to breast it fleetly enough for covert. And, as he looked, he saw the girl turn a frightened face toward her close pursuer and knew that she saw him as well. Her pace slackened for a moment as this revelation came to her, and he felt, somehow, that in him she recognized comparative protection. Then she recovered herself and bent all the power she had toward the ascent. But Oak had been gaining steadily, and now, with a sudden rush, he reached her and grasped her, the woman shrieking wildly. A moment later Ab rushed in upon them with a shout. Instinctively Oak released the girl, for in the cry he heard that which meant menace and immediate danger. As Lightfoot felt herself free she stood for a moment or two without a movement, with wide-open eyes, looking upon what was happening before her. Then she bounded away, not looking backward as she ran. [Illustration: AB STOOD THERE WEAPONLESS, A CREATURE WANDERING OF MIND]