As he went Ab engaged in deeper and more sustained thought than ever before in all his life. He was alone; new and strange scenes had enlarged his knowledge and swift happenings had made keener his perceptions. For days his entire being had been powerfully affected by his meeting with Lightfoot at the Feast of the Mammoth and the events which had followed that meeting in such swift succession. The tragedy of Oak's death had quickened his sensibilities. Besides, what had ensued latest had been what was required to make him in a condition for the divination of things. The wise agree that much stimulant or much deprivation enables the brain convolutions to do their work well, though deprivation gets the cleaner end. The asceticism of Marcus Aurelius was productive of greater results than the deep drinking of any gallant young Roman man of letters of whom he was a patron. The literature of fasting thinkers is something fine. Ab, after exerting his strength to the utmost for days, had not eaten of flesh, and the strong influences to which he was subjected were exerted upon a man still, practically, fasting. For a time, the rude and earth-born child of the cave was lifted into a region of comparative sentiment and imagination. It was an experience which affected materially all his later life. Ever to the trotting man came the feelings which must follow fierce love and deadly action and vague remorse and fear of something indefinable. He saw the face and form of Lightfoot; he saw again the struggle, death-ending, with the friend of youth and of mutual growing into manhood. He remembered dimly the half insane flight, the leaps across the dreaded morass and, more distinctly, the chase by the wolves. The aspect of the Fire Country and of all that followed his awakening was, of course, yet fresh in his mind. He was burdened. Ever uprising and oppressing above all else was the memory of the man he had killed and buried, covering the face first, so that it might not look at him. Was Oak really dead? he asked himself again! Had not he, Ab, as soon as he slept again, seen, alive and well, the close friend of his? He clung to the vision. He reasoned as deeply as it was in him to reason. As he struggled in his mind to obtain light there came to him the fancy of other things dimly related to the death mystery which had perplexed him and all his kind. There must be some one who made the river rise and fall or the nut-bearing forest be either fruitful or the hard reverse. Who and what could it be? What should he do, what should all his friends do in the matter of relation to this unknown thing?