How far his guard of wild, red man-things had taken him Dean Rawson could not know. Many miles, it must have been. And he knew that the air had grown steadily more stiflingly hot. But the heat of those long tunneled passages was like a cool breeze compared with the blasting breath of the room into which he was plunged.

It seared his eyeballs; it struck down from the tongues of flame that played in red fury in the recess high up on the farther wall. And the vast room, the fires, the hundreds of kneeling figures, all blurred and swam dizzily before him.

The hot air that he breathed seemed crisping his lungs. Vaguely, for the stupefying, brain-numbing heat, he wondered at the figure he saw dimly in its grotesque posturing close to the flames. And the hundreds of others how could they live? How could he himself go on living in this inferno?

They had been chanting in unison, the kneeling red ones. Dean heard the regular beat of their repeated words change to an uproar of shrill, whistling voices. But he could neither see nor hear plainly for the unbearable, suffocating heat.

The clamor was deafening, confusing; it echoed tremendously in the rocky room and mingled with the steady, continuous roar of the flames. The mass of bodies that surged about him made only a blurring impression; he tried to make himself see clearly. He must fight fight to the last! Only this thought persisted. He was striking out blindly when he knew that his red guard had cleared a way through the mob and was dragging him forward.

He knew when they reached the farther wall. Somewhere above him was the deep-cut niche in which the fires roared. And then, when again he could see from his tortured eyes, he found directly ahead another doorway in the solid rock. Beyond it all was black; it gave promise of coolness, of relief from the stifling air of the room. Red hands were thrusting him through.

The burst of water, icy cold, that descended upon him from above shocked him from the stupor that claimed his senses. He was drenched in an instant, strangling and gasping for breath. But he could think! And, as the lean hands seized him again and hurried him forward, he almost dared to hope.

To his eyes the passageway was a place of utter darkness, but the red ones, their great owl eyes opened wide, hurried him on. His stumbling feet encountered a flight of steps. With the red guard he climbed a winding stair where the tunnel twisted upward.

That icy deluge had set every nerve aquiver with new life. He hardly dared ask himself what might lie ahead. Yet he had been saved from that mob; it might be his life would be spared, that in some way he could learn to communicate with these people, learn more of this subterranean world which must be of tremendous extent. Without any sure knowledge of their plans, he still was certain in his own mind that they intended to swarm out upon the upper world. He might even be able to show them the folly of that.

A thousand thoughts were flashing through his mind when the tunnel ended. Beyond a square-cut opening the air was aglow with red. An ominous thunder was in his ears. Then a score of hands lifted him bodily and threw him out upon a rocky floor that burned his hands as he fell.

Heat, blistering, unbearable, beat upon him. He was wrapped in quick-rising clouds of steam from his wet clothes.

The platform ended. Far below was a sea of red faces, grotesque and horrible, where each held two ghastly white disks, and at the center of each disk a mere pinpoint eye.

He saw it all in the instant of his falling the inhuman, shrieking mob, the blast of hot flame not forty feet away at the back of the rocky niche, and, between himself and the flame, a giant figure that leaped exultantly, while its body, that appeared carved from metallic copper, reflected the red fires until it seemed itself aflame.

Dean knew in the fraction of a second while he scrambled to his feet, that the great room had gone silent. The roaring of the flames ceased; even the clamor of shrill voices was stilled. He had thrown one arm across his face to shield his eyes; the heat still poured upon him like liquid fire. But his instant decision to throw himself out and down into the waiting mob was checked by the sudden stillness.

To open his eyes wide meant impossible torture, yet he forced himself to peer through slitted lids beneath the shelter of his arm.

The flame was gone. Where it had been was a wall of shimmering red rock above a gaping throat in the floor, whose rim was quivering white with heat. Here the blast from some volcanic depth had come.

Then he saw it, saw the great coppery figure leaping upon him and saw more plainly than all this the end that had been prepared for him.

Fire worshipers! Demons of an under world paying tribute to their god. And he, Dean Rawson, was to be a living sacrifice, cast headlong to that waiting, white-hot throat!

The coppery giant was upon him in the instant of his realization. Somehow in that moment Dean Rawson’s wracked body passed beyond all pain. With the inhuman, maniacal strength of a man driven beyond all reason and restraint he tore himself half free from those encircling arms and drove blow after blow into the hideous face above him.

Only his left arm was free. That, too, was clamped tightly against his body an instant later.

The giant had been between him and the glowing rocks. Now he felt himself whirled in air, and again the blast of heat struck upon him. He was being rushed backward; and there flashed through his mind, as plainly as if he could actually see it, the scintillant whiteness of that hungry throat.

He tried to lock his legs about the big body to prevent that final heave and throw that would end a ghastly ceremony. The rocks were close, their radiant heat wrapped about him like a living flame. Abruptly his strength was gone the fight was over he had lost! His heart sent the blood pounding and thundering to his brain; his lungs seemed on fire.

The high priest of the red ones had his priestly duty to perform the sacrifice must be offered. But even the high priest, it would seem, must have been not above personal resentment. Sacrilege had been done a fist had smashed again and again into the holy one’s face. This it must have been that made him pause, that brought one big hand up in a grip of animal rage about Dean’s throat.

Only a moment a matter of seconds while he vented his fury upon this white-skinned man who had dared to oppose him. Dean felt the hand close about his throat. So limp he was, so drained of strength, he made no effort to tear it loose. He was dead what mattered a few seconds more or less of life? And then a thrill shot through him as he knew his right hand was free.

That hand made fumbling work of drawing a gun from its smoking, leather holster. He could hardly control the numbed, blistered fingers, yet somehow he crooked one about the trigger; and dimly, as from some great distance, he heard the roar of the forty-five.... Then, from some deep recess within him, he summoned one last ounce of strength that threw him clear of the falling body.

Instinctively he had heaved himself away from the fiery rocks; the same effort had sent his big coppery antagonist staggering, stumbling, backward. And Dean, sprawled on the stone floor, whose heat where he lay was just short of redness, heard one long, despairing shriek as the giant figure wavered, hung in air for a moment in black outline against the fierce red of a rocky wall above a white-hot pit, then toppled, pitched forward, and vanished.

Sick and giddy, he forced himself to draw his body up on hands and knees. Then he straightened, came to his feet, and staggered forward.

Below him was pandemonium. The sea of faces wavered and blurred before his eyes. From a distant archway other figures were coming. He saw the gleam of metal, heard the wild blare of trumpets, and knew that the hundreds of red ones below him were standing stiffly, both hands raised upright in salute as another barbaric figure entered. The air was clamorous with a shrill repeated call. “Phee-e-al!” the red ones shrieked. “Phee-e-al!”

But Rawson did not wait to see more. Behind him, the flames that had been fed with human flesh if indeed these red ones were human roared again into life. He had returned the pistol to its holster when first he came to his feet; his weak hands had seemed unable to hold it. And now his two hands were thrust outward before him as he staggered blindly toward the tunnel mouth.

It was where he had emerged upon the platform. His reaching hands found the side entrance where the stairs led down to the main hall. In the darkness he made his way past. Stumbling weakly he pushed on down the long tunnel whose floor slanted gently away.

Ahead of him was a light. The comparative coolness of these rocks had served to revive him somewhat. He had no hope of escape, yet the light seemed comforting, somehow.

He stopped. His stinging eyes were wide open. He stared incredulously at the glowing spot on a distant wall, where a flame must have touched, and at the figure beneath it.

The figure of a woman! A young woman, tall, slender, fair-haired, whose skin was white, a creamy white, whiter than snow.

A woman? It was a mere girl, slender and beautiful, her graceful young body poised as if, in quick flight, she had been caught and held for a moment of stillness.

What was she doing here? His exhausted brain could not comprehend what it meant. He had seen women of the Mole-men tribe mingling with the men. Like them their heads were pointed, their faces grotesque and hideous. Rawson gave an inarticulate cry of amazement and staggered forward.

Between him and the distant figure a crowd of Reds swarmed in. They came from a connecting passage. Above their heads the lava tips of flame-throwers were spitting jets of green fire. Every face was turned toward him at his cry.

Beyond them the white figure vanished. Dean, leaning weakly against the wall, told himself dully that it had been a phantom, a product of his own despairing brain and his own weakness. Then that weakness overcame him; and the red Mole-men, their white and hideous eyes, the threatening jets of green flame, all vanished in the quick darkness that swept over him....