Astounding Stories of Super-Science, August 1930

She manipulated the controls once more and there was a quick shift to another coast, a rugged, wave-beaten shore. Closer they drew until they observed a lofty palisade that extended for miles along the barren waterfront. They saw a fire atop this elevation and active men and women at various tasks within the narrow circle of its warmth. A cave mouth opened at the brink of the precipice near the spot they occupied. Then came a repetition of the upheaval at Trovus. The ocean rushed in and beat against the cliff with such ferocity that its spray was tossed hundreds of feet in the air. The earth shook and the group of people around the fire made a hasty retreat to the mouth of the cave. The sky darkened and the winds howled with demoniac fury. Quake after quake rent the rugged cliffs: huge sections toppled into the angry waters. Then a great tidal wave swept in and covered everything, cliffs, cave mouths and all. Nought remained where they had been but the seething waters. "But some escaped!" exulted Phaestra, "and these discovered Theros. Though many miles of the eastern seaboard of your United States were submerged and the coastline entirely altered, these few were saved. Their cave connected with a long passage, a tunnel that led into the bowels of the earth. With the outer entrance blocked by the upheaval they had no alternative save to continue downward." "They traveled for days and days. Some were overcome by hunger and fell by the wayside. The most hardy survived to reach Theros, a series of enormous caverns that extends for hundreds of miles under the surface of your country. Here they found subterranean lakes of pure water; forests, game. They had a few tools and weapons and they established themselves in this underground world. From that small beginning came this!"