Together they ran forward, down the corridor toward the gigantic brontosaur, which was regarding them with its small eyes in seeming perplexity, its head swaying to and fro on its sinuous neck as they neared it. Now they were to the great beast, pressing past it and between its great body and the corridor wall, its mighty bulk looming above them awe-inspiringly in the great corridor. As they ran past it the huge beast half turned, half stepped toward them, but as Morton repeated his strange high cry it halted again. The next moment Rowan breathed for the first time in seconds, for they were past the brontosaur and racing on down the corridor toward its open end.
As they neared that end they slowed their pace, crept forward more cautiously, until they were peering out into the great, crimson-lit street. The broad avenue seemed quite deserted and empty, and they sprang out into it, toward the central plaza where lay the lake of fire and its ascending and descending disk. But suddenly Morton turned, pointed back. Far down the street behind them a great mass of huge figures was moving toward them—a mob of mighty dinosaurs and lizard-riders which was coming rapidly up the avenue.
"They're coming now!" cried Morton. "They've gathered—they're ready—they're going to go up the shaft, now!"
From the advancing horde they heard, now, deep, gigantic bellowings, answered far across the great gray city by others like it, by other masses of dinosaurs and lizard-men moving toward the central plaza and the great lake of flame. Then abruptly the two men had turned and were racing madly up the avenue toward that lake, up the broad and empty street toward the great disk that was their sole hope of escape.
On and on they staggered until at last they were stumbling between the last gray buildings of the street and into the broad, clear plaza, toward the rim of its central basin of fire. Rowan looked up, as they ran, saw high above them a dark, expanding circle which was dropping down from a round black opening in the rock roof far above, dropping swiftly down toward the lake of fire ahead. And then he cried out, for emerging into the empty plaza directly across from them were a half-dozen of the lizard-men, who saw the two running men, and, uttering rasping cries, sprang around the rim of the flaming lake toward them.
The mighty disk was sweeping smoothly downward, now, down until it hung level with the plaza, above the basin's fires, and now Morton had flung forward across the two-foot gap and upon the disk. But as Rowan too leapt forward the racing lizard-men reached him, and as he threw himself upon the disk, which was rising now, one of them had leapt forward with him and pulled him back. He clung frantically to the great disk's edge, and then the mighty platform was rising smoothly upward while he and his lizard-man opponent clung dizzily to its edge, swinging above the flaming lake and striking at each other with their free hands.
Rowan felt himself carried upward with ever-increasing speed, heard the roar of winds in his ears and glimpsed the raging lake of fire below, and then felt his strength slipping from him beneath the blows of the lizard-man, who clung to the disk with one taloned claw and struck out with the other. Then, as Rowan felt his grip on the disk's edge slipping, loosening, there was a flashing blow from above which sent the scaled green body of his opponent whirling down into the flames beneath, torn loose from his hold. And as Rowan's nerveless fingers released his own hold a hand above caught his wrist, there was a tense moment of straining effort, and then he had been pulled up onto the disk's surface by Morton, and lay there, panting.
A moment he lay thus, then crept with Morton to the disk's edge and stared down with him at the gray city which now lay far below. They saw, pouring into the plaza, a great mass of huge dinosaurs and a vast throng of the lizard-shapes, an eddying throng that was moving now toward the plaza and the fiery lake from all the city's wide and branching streets. The next moment all this was blotted from sight as the disk shot smoothly upward into the darkness of the great shaft, flashing up that shaft amid a thundering of confined winds. Over the raging of those winds Rowan shouted in the other's ear.
"They've gathered down there!" he cried. "When the disk goes down again they'll come up with it, after us! We have only minutes——"
Morton shouted back. "The switch! If we could open that wheel-switch up there, let loose those fires below——"