Nu, a young hunter of the Niocene Age, must win Nat-ul by bringing back the fangs of Oo, the terrible saber-toothed tiger. His quest carries him through a savage prehistoric world of charging rhinoceroses, ape-people, cliffside hunts, and a brutal close-quarters battle with the monster itself, where only a stone hatchet, spear, and sheer courage keep him alive. Yet triumph is shattered by earthquake and collapse, and the story leaps a hundred thousand years ahead to Victoria Custer, a modern woman in equatorial Africa whose irrational terror of earthquakes and recurring dreams of a powerful, mysterious man suggest an ancient bond. As Victoria is drawn between real-world love and primal memory, another quake reveals Nu sealed in a hidden cave, awakening him into a new age with his instincts intact. He survives by killing a cave-bear, making fire, and searching for his people, while Nat-ul endures her own dangerous path, outwitting a savage pursuer, encountering the strange Boat Builders with their domed shelters and log-boats, and fleeing the warrior Tur. Meanwhile, Nu returns to his tribe only to find unease, Nat-ul missing, and a darker mystery unfolding in this vivid blend of prehistoric adventure, romance, and survival. This edition has been fully restored with modern typesetting, custom cover design.