A girl whose creamy body was strangely unsoiled by smoke or grime, whose jeweled breast-plates flashed in the light of her torch while the loose wrappings about her waist whipped against her as she ran. And Rawson, naked but for the golden loin cloth, running beside her. Then Smithy, and ten others in the khaki uniform of the service it was all that was left of the fifty who had dared the depths. And now all of them were harried and driven like helpless animals in the burrows and runways of that under-world.

But not entirely helpless. Colonel Culver had been right: their rifles outranged the flame-throwers. And Rawson, looking past that first burst of rifle fire, saw the one flame that had reached them whip upward as its owner fell. Others of the Reds came crowding in after, and the jets of their weapons made little areas of light as they crashed to the floor. Then Colonel Culver took charge of the retreat.

Ahead of them and behind them was impenetrable darkness; only the nearby walls were illumined by the torch that Loah had been forced to turn on. And out of that darkness at any moment might come devastating flames. Culver detailed two men as a rear guard and two others to run ahead a few paces in advance. At intervals of a minute or two their rifles would crack, and the echoes would be pierced by the whining scream of ricochets, as their bullets glanced from the walls.

“We may not need them up ahead,” Culver shouted to Rawson. “I don’t understand it. The place seems deserted there were plenty of them here before!”

“They’ve got something else to think of,” Rawson shouted in reply. “I killed Phee-e-al he was their leader. But they’re after us now. They’ll be running through other passages, cutting in ahead of us.”

The tunnel turned and bent upward. For a full half mile they ran straight in a stiff climb. Between gasping breaths Colonel Culver shouted hoarsely: “Won’t it ever turn? If they bring up their damned heat-ray machines they’ll get us on a straightaway like this!”

Then Smithy’s voice outshouted his with a note of hope: “We’re almost there; I remember this place. There’s where we mounted the searchlight. They’ve ripped everything out. Up ahead, one turn to the right, then a quarter mile, then a turn toward the crater. That runs straight for a mile, but there’s a field gun at the bottom of the volcano. We’ll be safe when we’re on that last stretch.”

Ahead of them the rifles of the two who ran in advance crashed out in a fury of fire as a green glow appeared. But this time the flame did not die; and Rawson, staring with hot, wide-opened eyes, saw that the ribbon of green swept transversely across the tunnel.

He could hardly stand when he came to a stop. Beside him Loah was swaying with weariness. The walls echoed only the hoarse, panting breath of the men. Then they crept slowly forward, where the passage went steadily up. Loah’s light was out; she had slipped the cap on the torch at the first sight of that green.

They stopped but ten feet short of the deadly blaze. From a narrow rift in the left wall it streamed outward, the rock at the edges of that crack turning to red at its touch. It beat upon the opposite wall, where already the stone was melting to throw over them a white glare and the glow of heat. And, like a shimmering, silken barrier, whose touch could mean only instant death, it reached across the wide tunnel at the height of a man’s waist and moved slowly up and down. The heaviest armor plate ever rolled could have formed no more impenetrable a barrier.

“And we almost made it,” said Smithy slowly. “Look, beyond there another hundred feet. There’s the bend in the tunnel, a sharp turn and we almost got around!”

Rawson reached for Loah’s light. In the wall where the flame was striking, only a dozen steps back, he had seen another dark mouth, a ragged crack in the rock. He sprang to the entrance; it might be there was another way around. His first glance told the story, for he saw the walls draw together again not a hundred feet off.

“A blind alley,” he groaned.

One of the two who had been their advance guard snapped his rifle to his shoulder. He was aiming at the glowing crack where the green light was issuing.

“A ricochet,” he growled. “It may go on in and mess ’em up.” But there was no whine of a glancing bullet that followed his shot; the softened wall had cushioned the impact.

Another man sprang beside him. He was shouting at the top of his voice while one hand reached into a bag that hung at his waist. “Get back, everyone,” he said. “If I miss....” He did not finish the sentence, but pulled the pin from a hand grenade, then took careful aim and threw.

It went high thrown there purposely; he had not dared aim it into the flame. But it struck the crevice fairly, and they heard it rattle on inside. The next instant brought the crack and roar of its explosion.

Like a winking signal light the green barrier vanished. Where it had been was only blackness and the dying glow of molten rock. Then, a hundred feet beyond, up close to the roof, the bend of the tunnel turned red; it seemed bursting into flame. Far back of them, down the long sloping way where they had come, shrill voices were screaming and still there was no green flame to account for that tunnel end flaming red.

Rawson stood motionless. Loah, and the others beside him, seemed likewise petrified, until the voice of Culver jarred them into action.

“The ray!” he shouted. “It’s the heat ray, damn them! Quick, jump into that cave!”

They had all retreated through fear of the grenade; they were opposite the black place into which Rawson had looked. Loah was close beside Dean; he threw her with all his strength into the black mouth of the cave, then he was one of a crowding, stumbling mass of men who followed after, and their going was lighted by a terrible torch of flame.

One man had stood apart from the others, farther across the wide corridor. His khaki-clad body flashed suddenly to incandescence, then fell to the floor. And inside the cave, where the walls came abruptly together to cut off any further retreat, Colonel Culver spoke softly.

“One more gone,” he said. “That was Oakley. Well, he never knew what it was that hit him and it looks as if we’ll all get the same.”

Through it all, Rawson had clung to his flame-thrower; unconsciously his hand had held fast to the bent handle of the cylindrical weapon. Now he set it down slowly upon the floor, then straightened his aching body laboriously.

Loah’s light was still gleaming. He saw her eyes searching for his, half in terror, half in wonderment. Strange men with strange thundering weapons he knew she was wondering if they still dared hope, wondering if these warriors of Rawson’s race might be able to work further magic.

Dean put one arm tenderly about her and drew her close and his other hand came to rest upon Smithy’s shoulder.

“It’s the end, dear,” he told the girl softly. “It’s the end of our journey. You’ve been so dear and so brave. Pretty tough to lose out when we’d almost fought clear.” Then, to Smithy: “Loah came back to save me refused to go when she could have got away and been safe.”

Already the air was stifling. The tunnel beyond the mouth of the cave was hot, though only at its end, where the invisible ray struck the rock surface squarely, was there red, glowing heat. Rawson suddenly saw none of it. He was seeing in his mind the world up above, his own world of great, free, sunlit spaces. Suddenly he was hungry for some closer link, no matter how slight, to bind him to that world.

“What day is it?” he asked. “Have you kept track of time?”

Smithy looked at him wonderingly. “Yes,” he said, then added: “Oh, I see. You want to know what day this is when we die. It’s the twentieth, Dean” he looked at the watch on his wrist “just two o’clock, the afternoon of the twentieth.”

Within him, Rawson felt a dull resentment. He was being denied even this last trifling solace. “You’re wrong,” he said sharply. “You slipped up on your count.”

“It doesn’t make any real difference,” Smithy said. But Rawson went on:

“We left the inner world on the nineteenth. At noon on the twentieth Gor was to cut loose the flame-throwers, melt a hole in the floor of the ocean. But it didn’t work. I had hoped I could wipe out the mole-men, turn a solid stream of water down a shaft for over six hundred miles. It would have gone through the Zone of Fire, come flooding up into the mole-men world and spread out all over down deep where it’s hot. It would have hit the Lake of Fire all that!”

“I don’t know what you are talking about, Dean.” Smithy’s voice was intentionally soothing; he knew Rawson was talking wildly. “But I know I am right on the time. We’ve kept track of it every hour since ”

Rawson’s talk had sounded like insanity in Smithy’s ears. He would have gone on he didn’t want to see Dean Rawson go out like that but now he stopped. The rock was quivering beneath his feet.

And now Rawson, with a wild wordless cry, threw himself toward the flame-thrower on the floor. His voice rose to what was almost a scream. “It’s worked!” he shouted in a delirium of joy. “It’s the end of the brutes!”

Then, in words which the others could not comprehend but which somehow fired them with his own emotion: “Gor has cut it loose! Water, millions of tons of it! The Zone of Fire steam!...” He threw himself flat on the floor as close to the hot mouth of the cave as he dared go, and the green flame of his weapon ripped outward and up as he aimed it.

From the passage, where it sloped downward toward the source of the heat ray, the sound of shrill, whistling voices had swelled louder. The whole tunnel now glowed green from the flames of an advancing horde. They were bringing their ray projector with them, Rawson knew, not that its beam was visible, but the white, dazzling glow from the end wall where the tunnel turned was still there.

“Shoot above me!” Rawson shouted. “Don’t stick your guns out into that ray, but aim as straight down the tunnel as you can. Keep ’em busy. Keep ’em from coming too close.”

Above his head he heard the beginning of rifle fire as the men crowded close to aim at the opposite wall at as flat an angle as they could. The air grew shrill with the sound of ricochets as the bullets glanced, but still the enemy came on, as their screeching voices told.

His own weapon was aimed up above. The roof of the tunnel was rough and broken. He directed the flame against the top of a great black granite block. In one place it was fractured. If he could cut it off above, make it fall to the steeply slanting floor.... He worked the full force of the blast methodically along the line he had chosen.

The air of the tunnel had been blowing gently, but now it came in sharp gusts that whipped in through the mouth of the cave, while it brought an unending growl and roar like distant gunfire from deep within the earth. The breeze had swelled to a steady blast when the rock crashed down.

“But that’s no use,” Culver had shouted, when the deafening sound of its fall had ceased. “They’ll melt it in a second with their ray.” Even as he spoke the great mass of granite softened and rolled downward as the enemy shot their ray on its lower side. The heat of it struck blastingly into the entrance to their retreat, yet still Rawson kept on, sawing doggedly with the weapon of flame at other great blocks above.

Now that distant thunder grew hugely in volume, and again the rocks trembled beneath them. The wind in the tunnel grew suddenly to a wild blast. It brought to them from a thousand other passages, the shrill, demoniac shrieking of air that was torn and ripped on projecting ledges of rock. Mingled with it was the sound of voices that screamed in terror, and the echo of feet running in mad flight down the tunnel.

The mass of stone, that had been melting under the invisible ray, cooled to red, then to black. Outside, the tunnel, now a place of roaring winds, was lighted only by the single flame of Dean’s weapon.

“They’ve gone!” Culver shouted. “The ray’s off. Get outside! Now we’ll run for it!” And, with the others, Rawson sprang to his feet and leaped out into the tunnel which was no longer a place of death.

He heard the sound of their hurrying feet and a voice that cried: “Look out for the turn the rock’s hot,” but he did not look after them. He was standing squarely, bracing himself in the blast of air, still directing the flame upon a block that hung stubbornly and would not let go.

He knew that Loah alone stood near. He heard other feet; someone was returning. Then Smithy was upon him, almost jarring him from his careful pose. Smithy was shouting.

“Come back, Dean!” he cried. “Are you crazy? Don’t you know they’ll be after us again?”

Rawson sprang as the big rock let go. It, too, crashed deafeningly upon the floor and rolled sluggishly downward beside the high hummock of glass that the first rock had become. They bulked hugely in the passage. They were eight or ten feet high, reaching across from one wall to the other.

Above them was still a space of four feet; Rawson estimated it carefully while he looked at the ceiling above. Then he shook off Smithy’s hand that was dragging at him and returned to the attack; for now, above the top of the barricade he had built, white ribbons of vapor were streaming. He had to shout to his utmost to make Smith hear above the shrill shriek of the blast.

“Steam!” he screamed into Smithy’s ear. “Live steam! We could never make it before we got to the top we’d be cooked to a pulp. I’ve got to block it, got to seal it off.” A whole section of the ceiling tore loose as he spoke, and the wind raised its voice like the scream of a wounded animal or the cry of an overwhelmed and stricken people as it tore through the space that remained.

It whipped the molten drops as they fell and made of them a deadly rain. Rawson, staring through the clouds of hot steam that now wrapped him about, called to Smithy to take Loah to safety, and kept the flame where it should be until at length the last aperture was closed, the last gap in the wall filled in. And even after that Rawson kept the flame still playing above that wall till he had melted rock and more rock that flowed down to make the barrier a single heavy, solid mass.

Steam was coming now from the narrow cleft where the green light had flashed out to bar their way. But that was simple, and he sealed the gap shut with his flame.

He was gasping. The radiant heat from that molten mass had been torture that his naked body could never have borne but for the desperate necessity that drove him.

Smithy and Loah were again beside him. “Now,” he choked, “we can go, but if there are any cross passages I’ll have to block them too.”

“There aren’t,” said Smithy, and added: “I thought you were crazy. You’ve saved us all, Dean; we never could have made it to the top. That steam was getting hot hot as if it had come right out of hell.”

“It did,” said Rawson. Then the flame-thrower fell from his nerveless hand. He was swaying; his knees were trembling with weakness when Smithy and Loah, on either side, took his burned arms tenderly and helped him on where the others had gone.

Colonel Culver and a rescue party met them halfway. The Colonel had seen his men safely to the bottom of the volcanic pit. Others had run from their station beside a field gun to meet them; then Culver had called for volunteers and had gone back. And now there were plenty of willing arms to help.

The big lift, with its platforms of metal plates, awaited them at the tunnel’s end. There was room on it now for all who were left; there was no crowding of men’s bodies as there had been on the downward passage. Rawson was stretched on the floor-plates, whose touch was cool to his tortured body. Loah was seated that his head might rest in her lap on that absurd little fragment of skirt. She bent above him, whispering brokenly: “Dean-San my dear my own Dean-San! We live, Dean-San. I can scarcely believe it, but I know that we live, for I still have you.”

But Dean was able to stand when that journey was done. First, though, there were men who placed him carefully on a stretcher and carried him, when he commanded, to the crater’s outer rim. On the ashy floor of the crater a big transport was waiting with idling motors, but Dean would not let them put him inside. He wanted to look out across the world, to see it in reality as he had seen it in his own mind when all hope was gone. He wanted to look out once more across Tonah Basin and let his eyes rest upon country he had known.

Loah and Smithy walked beside him, as the first-aid men carried him toward that distant rim. The rocks there were cleft it was the place where he first had seen the inside of the crater’s cup. There he had them put him down; and, with the help of Loah and Smithy, he got slowly to his feet. While they lifted him, he wondered at the sound in this desert world where no sound should be. A terrific rushing, an endless roar and then his eyes found the clouds of steam.

Below him was the Basin, the tangled wreckage of his camp. And there, where the derrick had stood, was a tall plume of white. It did not begin close to the ground superheated steam, until it cools and condenses to water vapor, is invisible but a hundred feet above the sand. And, from there on up, two thousand feet sheer into the air, was a straight shaft of vapor, rolling up for another thousand feet into billowing clouds that the afternoon sun turned to glorious white.

“Power!” gasped Rawson. “Power and it will be like that indefinitely!” Then he laughed weakly. “I had to go down there to do it, to make Erickson richer, but it was worth it. In there the ocean will slowly subside. Gor and his people will find their lost lands; the column of water in the shaft will hold the back-pressure of steam. And here, I have Loah, and that’s all but that’s enough!”

He put one arm, still with the bandages of the first-aid men, about the girl. “I hope you’ll be happy, dear,” he said softly, and turned back. But Smithy barred the way.

“That isn’t all,” said Smithy jubilantly. “You see, Dean, Erickson fired you Erickson thought you had run out on him. Instead of backing you up, he quit. So I bought them all out. Whatever is there, Dean and it’s worth more millions than I dare to think about you own half of! Now get back on that stretcher. Just because you’ve saved all our necks up here on top of the earth, you mustn’t think you can keep an Army ship waiting all day!”