So the cave man struggled in his dim, uncertain way with the eternal question: "If a man die shall he live again?" So the human mind still struggles, after thousands of centuries have contributed to its development. A wall more impassable than the wall of flame Ab had so lately looked upon still rises between us and those who no longer live. We reach out for some knowledge of those who have died, and go almost into madness because we can grasp nothing. Silence unbroken, darkness impenetrable ever guard the mystery of death. In the long ages since the cave man ran that day, love and hope have in faith erected, beyond the grim barriers of blackness and despair, fair pavilions of promise and consolation, but to the stern examiners of physical fact and reality there has come no news from beyond the walls of silence since. We clamor tearfully for some word from those who are dead, but no answer comes. So Ab groped and strove alone in the forest, in his youth and ignorance, and in the youth and ignorance of our race. Upon the pathway along the river's bank Ab emerged at last. All was familiar to him now. There, by the clump of trees in the flat below, was the place where he and Oak had dug the pit when they were but mere boys and had learned their first important lessons in sterner woodcraft. Soon came in sight, as he ran, the entrance to the cave of his own family. He was home again. But he was not the one who had left that rude habitation three days before. He had gone away a youth. He had come back one who had suffered and thought. He came back a man. CHAPTER XXI. THE WOOING OF LIGHTFOOT. Lightfoot, when Ab seized Oak, had fled away from the two infuriated men, as the hare runs, and had sped into the forest. She had the impetus of new fear now and ran swiftly as became her name, never looking behind her, nor did she slacken her pace, though panting and exhausted, until she found herself approaching the cave where lived her playmate, Moonface, not more than an hour's run from her own home.