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.