Waldo hesitated but a moment before he reached a decision, and then he turned up the trail away from the river, and at a rapid trot followed the spoor along its winding course through the jungle to where it emerged at the base of the foothills, to wind upward toward their crest. He found that the trail he was following crossed the hills but a few yards from the spot at which he had met the cave man a short time before. Evidently the man had been returning from the river when he had espied Waldo. The young man could see where the fellow's tracks had left the main trail, and he followed them to the point where the man had stood during his conversation with Waldo; from there they led toward the east for a short distance, and then turned suddenly north to reenter the main trail. Waldo could see that as soon as the man had reached a point from which he would be safe from the stranger's observation he had broken into a rapid trot, and as he already had two hours' start Waldo felt that he would have to hurry were he to overtake him. Just why he wished to do so he did not consider, but, intuitively possibly, he felt that the surly brute could give him much more and accurate information than he had. Nor could Waldo eliminate the memory of those dainty feminine footprints. It was foolish, of course, and he fully realized the fact; but his silly mind would insist upon attributing them to the cave girl--Nadara. For two hours he trotted doggedly along the trail, which for the most part was well defined. There were places, of course, which taxed his trailing ability, but by circling widely from these points he always was able to pick up the tracks again. He had come down from the hills and entered an open forest, where the trail was entirely lost in the mossy carpet that lay beneath the trees, when he was startled by a scream--a woman's scream--and the hoarse gutturals of two men, deep and angry. Hastening toward the sound, Waldo came upon the authors of the commotion in a little glade half hidden by surrounding bushes. There were three actors in the hideous tragedy--a hairy brute dragging a protesting girl by her long, black hair and an old man, who followed, protesting futilely against the outrage that threatened the young woman. None of them saw Waldo as he ran toward them until he was almost upon them, and then the beast who grasped the girl looked up, and Waldo recognized him as the same who had sent him toward the west earlier in the day. At the same instant he saw the girl was Nadara. In the brief interval that the recognition required there sloughed from the heart and mind and soul of Waldo Emerson Smith-Jones every particle of the civilization and culture and refinement that had required countless ages in the building, stripping him naked, age on age, down to the primordial beast that had begot his first human progenitor. He saw red through blood as he leaped for the throat of the man-beast whose ruthless hands were upon Nadara.