Rowan gasped. The switch! That switch which the lizard-men had themselves prepared, to use after they had all come up from their cavern-world. If they could open it, could release upon that cavern-world the raging fires which pressed against its walls, it would mean annihilation for the lizard-people and all their giant reptile hordes. If they could——
Abruptly he grasped the other's arm, pointed mutely upward. Far above them a spark of pale white light was glimmering, a spark that changed to a spot and then to a little circle of pallid light as their disk-platform flashed up toward it with tremendous speed. And now, as that circle of white light widened, the disk was beginning to slow its speed a little, the downward-flashing metal walls beside them were moving past them more slowly. Up, up the great disk lifted, while the two men crouched tensely at its edge, and then it had floated up until it hung level with the mouth of the great shaft, beneath the radiance of the suspended bulb.
It was night once more on earth, Rowan knew, but the brilliance of the white bulb overhead was dazzlingly revealing as the disk swept up to hang at the shaft's mouth. In the moment that it hung there both he and Morton threw themselves from it onto the surface of the mound, and then as the great disk sank downward once more into the shaft they saw that their movement had not been observed, since the only figures on the mound were a half-dozen of the lizard-men armed with the white heat-beam globes, who lounged near the great three-pillar switchboard, at the opposite edge of the mound from the two men. They had not turned as the great disk reached the shaft's mouth and sank again, and after a moment of crouching Morton whispered to Rowan, who crept slowly off the mound in obedience to that whisper and into the shelter of the dark bordering forest around it. There he began to slip through the trees, stealthily, while on the mound itself he saw Morton crawling snakelike around the great shaft's edge toward the switchboard. Minutes passed while the two crept on, from different sides, minutes that seemed eternities to Rowan, and then he had reached the edge of the mound near the switchboard and was gathering himself for a dash toward it. And in that moment he was discovered. There was a harsh cry from one of the lizard-men guards at the mechanism and instantly two of them had leapt toward him, across the mound.
Rowan sprang to his feet, but before he could gain the surface of the mound he was borne down by the charging of the two sealed shapes, thrust back into the swamp from the mound's edge and struggling in their grip. He heard another cry, glimpsed the other guards on the mound springing toward Morton, who had half risen; then all other sounds in his ears, the rasping cries of his opponents, the deafening winds from the great pit, the panting of his own breathing as he whirled about—all these sounds were suddenly dwarfed by a sound that came to his ears like the thunder of doom, a deep, throaty bellowing coming faintly as though from far beneath but growing swiftly louder, nearer, coming up the shaft from the ascending disk there!
"Morton!" he cried. "Morton!"
Then he saw Morton whirl sidewise from the guards who ran toward him, saw him leap toward the great switchboard and toward the wheel-switch at its center, felt himself thrust backward as his two opponents rushed back onto the mound with frantic cries. At the same moment the giant disk swept up again to the shaft's mouth, hanging there, crowded with massed lizard-men and a half-dozen of the huge tyrannosaurs. Out toward Morton leapt these gleaming-fanged monsters, and from a score of the lizard-men on the disk and on the mound there stabbed toward him rays of pallid light. But in the second before those deadly rays could be released Morton had grasped the great wheel, had spun it around in one frantic motion. The next moment the machine and Morton beside it had vanished in a flare of blinding flame, but even as they did so there came from far beneath a gigantic rumbling and crashing, a rending crash as of riven worlds, while the ground beneath Rowan swayed and rocked violently. The next moment there had burst up the shaft a vast gush of crimson fire, a molten flood bursting up from the suddenly released seas of molten fires below, annihilating the great disk that hovered in the shaft, raining in fiery death upon all on the mound, falling hissingly into the water and slime about Rowan. Then was another rumbling crash and the mound itself seemed to buckle, collapse, as the walls of the great shaft below it collapsed, and then before Rowan there lay only a vast, smoking gouge in the earth, with no sign of life in it.
For minutes Rowan stared, unable to credit the miracle which had taken place before his eyes, which had thrust back the lizard-men and all their dinosaur hordes at the last moment, annihilating them in their cavern world far below by the switch they had themselves prepared, by the molten fiery seas of earth's heart which Morton's hand had loosed upon them. But for all the incredulous emotion within him he could find no words, could but stretch out his hands speechlessly toward the steaming pit before him.
And then suddenly he became aware that he was weeping....