"Then it is time to go!"
She looked for a moment at her father, stretched out as though in sleep upon the dark mantle, his head pillowed on the grass.
"Leave him here in his city," she said.
She turned and sprang to Hatha's back. Nelson also mounted, and they galloped northward out of Vruun after the Clans. Smoke coiled thick among the trees, lit by the strange red glow. Ash fell more heavily and the wind brought burning showers of sparks.
Looking back minutes later, Nsharra cried, "The city burns!"
Nelson looked back also and saw the flames leaping triumphant behind them. They flared in great twisting banners from the treetops, turning the forest-ways into red rivers of fire that flowed northward. The crest of that fiery flood raced after the fugitives, roaring, dancing, eating the trees as it pursued.
"Faster or we'll be trapped!" Nelson shouted.
He saw how the glassy bubble-roofs back there had turned smoky red as the flames washed over them. They did not burn or crack but they glowed in the terrible heat, the minarets throwing back the crimson glare.
Choking, coughing, burned by flying sparks, Nelson and Nsharra and the Clan-leaders raced ahead of the leaping flames. Nelson clung desperately to his mount as the Hoofed One smashed through brush, leaped dry gullies, bucked and scrambled over fallen trees. He could barely see the others in the smoke.
They burst out of the woods onto the open plain that rose ahead of them to the barren foothills. Another spurt, another staggering burst of speed and they were safe. The fire flared to the edge of the woods and checked.
Now, close above them, Nelson saw the throbbing eye of the Cavern of Creation, pulsing with mysterious light. The Clans were moving up on either side of that coldly flaring orifice, on up into the higher bare hills.
On a flat ledge just outside the glowing mouth of the Cavern, Nelson stopped and dismounted. Nsharra did likewise.
She told the four leaders, "Nelson and I go into the Cavern! You lead your Clans on to safety."
Nelson cried, "No! You're not to stay in there with me, Nsharra — only to show me the way!"
"I am Guardian now," Nsharra said firmly. "It is my duty and my right to go with you."
He realized from her tone that argument would not sway her. And there was no time for argument. Time was running out.
"I go also!" Tark's thought cried and the other leaders echoed him.
"No!" Nsharra denied. "You also have your duty- to lead your Clans to safety."
Wolf and tiger, horse and eagle, wavered, irresolute. Then, as Nsharra repeated her command, they unwillingly went on into the darkness of the upper slopes.
Nelson uttered an exclamation. He had turned to look back, and now he pointed downward. By the glaring light, they could see Nick Sloan's rafts coming down the blood-red river past the blazing city.
"They'll be up here soon," he said edgedly. "Nsharra, there's still time for you to get away!"
"I will show you the safe way into the Cavern, now," she answered. "But I am its Guardian and I will not leave it!"
He turned with her toward that great mouth of cold, quivering light. Deliberately, Nsharra led the way into it.
Just inside the entrance she paused. Nelson looked about. Where the light outside had been red and hot, here it was a cool glow like uncanny moonlight.
The cavity was huge and circular, running back into the hill. Nelson guessed it to be eighty feet high. A hundred feet from where they stood yawned a deep cleft that ran across the cavern floor, and it was from here that the cold light came — a terrific blaze of white radiation flung upward out of the cleft.
Nelson began to see things that astounded him even more than his first sight of Vruun and Anshan.
Great circular ribs of metal, massive girders dim in the lofty gloom, seemed to support the roof and sides of the Cavern. He made out the shapes of metal tubes, gigantic things, crumpled and twisted as though by blasting force, that ran along the walls into the unguessable shadowy spaces farther in.
His brain began to reel with impossible conjectures. Stepping forward toward the cleft, he glimpsed a glowing white mass that lay deep down at the bottom of the crevice.
Nsharra drew him back. "Do not go too close to the cold fire — its light can blast and kill!"
"Radioactive!" Nelson muttered incredulously. "A radioactive chemical mass of some sort that's eaten its way into the floor."
Very effectively, that moat of death had barred all entrance into the unguessable farther depths of the Cavern.
He looked up along the wall above the cleft and made out vast twisted cylinders, their metal sides burst and gaping. There was no mistaking what those cylinders were. They were huge tanks.
Had the radioactive mass spilled from those shattered tanks? It seemed obvious and yet—
Nsharra led him to the end of the mass of giant tubes that ran along the walls back to the farther depths of the Cavern. The tubes were all of six feet in diameter, made of unfamiliar metal, massive and thick. He tried to picture them as they must have been once and the picture staggered his mind with suggestions that were pure madness.
Nsharra said, "Most of these strange tunnels are broken. But one of them leads safely over the cleft of cold fire. It is the secret way, found long ago by a Guardian and told only to his successors."
She climbed into the flared ripped end of one of the giant tubes, motioning him to follow. He did so, using his pocket light. The inner wall of the tube was pitted and scored, the metal burned. Yes, burned, like a charred log. And yet it seemed amazingly tough metal. It acted as a shield against the deadly radiation they were crossing.
Numbly Nelson wondered what terrible force had ripped through these giant tubes to scar them so.
Ahead of him, Nsharra came to a place where the tube twisted upon itself. He scrambled with her around the turn. Then, suddenly, he snapped off his light and whispered quickly to her.
"Silence!"
They crouched and listened, and Nelson heard plainly this time the sound that had warned him-a sound of something slipping and scrambling behind them in the tube, something straining to overtake them.
He had his gun out and ready when Tark's thought came to them. "Where man can go wolf can go! And where Nsharra goes this wolf goes also!"
Nelson relaxed and swore. Tark scrambled toward them, digging his claws into the pitted metal.
"Too late for anger now," he thought to Nsharra. "The outlanders and Shan Kar's men have already landed." He added with a wolfish shrug, "And anyway my Clan is safe now."
Nsharra's hand briefly touched the massive hairy head, but she did not speak. They went on for what seemed a long time in the tube. Then it debouched into a round gigantic metal chamber that looked to Nelson very like part of a turbine — a turbine built by giants for some unguessable purpose.
"Giant tubes that could be jet-tubes!" he said half aloud in a stunned voice. "This colossal turbine — and the radioactive chemical from the tanks, that could be fuel—"
"Come," said Nsharra and he followed her, the wolf keeping close to them as though awed by this forbidden place.
As they stepped out of the shattered turbine, well beyond the deadly cleft, Nelson could look into the shadowy farther spaces of the Cavern that previously the cold radiance had hidden from him.
He was not really surprised at what he saw. Shocked, stunned, awed, but not really surprised. Before him stretched the Cavern, vast, incredible, shadows glooming thicker as the eye went back into it.
And its half-seen, half-guessed shape was the shape of a torpedo, tapering from blunt stern to slender point. A sharp, clean point to cleave the air, to cleave, perhaps, the vast gulfs where there was no air, where only the stars rubbed shoulders with eternity!