Slowly Carruthers guided Nanette back towards the ring of rocks--perhaps the barrier would serve to keep the animals away. He scrambled across one of the boulders and pulled the girl after him. As he did so, a violent subterranean action shook the electron from one end to the other. * * * * * Carruthers braced his feet against the ring of rocks to keep from pitching headlong to the ground. Nanette clung to him wordlessly. All around them the giant forces of nature raged sullenly. Twisting seams appeared in the rocky floor of the plateau from which oozed gaseous vapors. "Courage," soothed Carruthers as he held the quivering body of the frightened girl close to his own. "This can't last." But the ground continued to lurch and heave on its axis. Vivid lights crossed and criss-crossed the atomic heavens. The fissures in the ground appeared now as black canals. The lower part of the circle of boulders disappeared. Off to the right came despairing screams. White bodies glowed for an instant against the background of flames. "Zark!" shouted Carruthers, as he saw the leader of the tribe of Esau and his followers making their way along the plateau top. Zark must have heard the earth-man's voice, for he started forward at a run. Simultaneously there appeared a herd of the greatest of all the prehistoric monsters--the Brontosaurus. They balked enormously against the flame-licked skies. Zark and his followers attempted to avoid them. But fear of the scorching flames drove the monsters forward. There followed a maddening moment of unutterable pain for the remaining ones of the tribe of Esau, then the herd trampled them underfoot and rumbled towards the half circle of rocks where the two earth people were crouched. The leader of the Brontosaurus herd trumpeted madly and barged for the higher ground of safety. Too late did instinct warn it of the widening fissure underfoot. Before it could stop the pressure of the herd drove it into the crevice. * * * * * Carruthers drew back to the extreme inside edge of the boulders trying to still his ears against their insane bellowings. A cloud of heavy, choking smoke enveloped him for a moment then passed away. Then it was that he saw a new star in the atomic heavens,--a star that seemed to burn with the brilliance of a meteor. Even as he watched he was conscious of it drawing closer. The planet was now in a continuous uproar. The ground was heaving and trembling as if from some inward strain. This was the end. Carruthers realized it with a sinking heart. In another minute the electron would disintegrate into a flaming mass of matter and fling itself from its orbit around the atom.