Against the blackness of the early morning sky the huge ball traced an arc of flame. Had Karn been watching the sky he would have seen the ball slow in its descent and then come to a landing some distance ahead of him. But he was too busy for that.

On the back of his neck the short hairs told him that pursuit was still close behind. He put on a fresh burst of speed, his bare feet making no sound on the trail he followed. Soon the early breeze would s.h.i.+ft and they would lose his scent.

Until then he was in danger from the males of Tur's tribe. Tur the coward, Karn thought. Tur the bully. Tur the leader of the tribe. Tur had never liked Karn. He had liked him even less as he grew into magnificent Cro-Magnon manhood. Karn represented the challenge that must come to every leader sooner or later.

Then the wind s.h.i.+fted and Karn slowed. They'd give him up now. He was certain of that. But what to do next? He was all alone, an outcast from his tribe. For a full-grown man to find another tribe was impossible.

Still, he wasn't sorry about the fight. It had been a good one. Tur was still in his prime. He'd used his teeth and his feet and every trick he knew. He wasn't quite as strong as Karn, nor as fast, but he'd had the advantage of experience.

Only one thing Tur lacked, in common with the other members of the tribe, and it was that which had lost him the fight. He had almost no inventiveness. For Karn's questing mind Tur hated him. He could not understand a man who found interest in new situations. And what Tur could not understand he hated.

So they had fought. For a while Tur held the upper hand. He had met every rush of Karn's and repulsed it. But Karn had noticed that every attack from Tur's left was met by a singular twist of the chief's body.

Once Tur twisted. Twice; a third time; and a fourth time he swung around. The fifth time Karn was not there. He'd stopped himself in mid-stride, reversed himself and caught Tur off balance. Then steel fingers had fastened on Tur's throat in unshakable tenacity.

That was when the other males had charged to his rescue. Tur, they hated. But Karn they hated more. Karn made up his mind quickly. Glat alone he could have torn limb from limb. Waan alone would have fared no better. But they and the others together represented for him a quick and certain death.

Then it had been run, run, run. Run with all of them after him. Run into the forest in the night. Only the giant wolf and the saber-tooth there. But they were not half so deadly as his own blood relatives.

Now the chase was over. Karn paused, his chest heaving. In a few minutes his breathing was back to normal. It didn't take this man long to recover. Karn grinned into the darkness. It would take Tur longer. He'd wear those welts on his throat for a while.

Karn shrugged and sniffed the night air. Better move ahead. No smell of the big cats. But there was a nest of wolves off to his right. They slept now, but soon they'd be awake. Up ahead there was a strange scent, one he didn't recognize.

Should he go on or turn aside? Ahead there was a glade where a spring bubbled. Small animals came to drink there in the morning. That meant food and water to a man who needed both. Karn moved ahead, but warily.

The rising sun found him only a short distance from his objective. Now there were mingled sounds as the forest came awake. Early-opening flowers filled the air with fresh sweetness. It was good to be alive.

Then, through a thin screen of trees, Karn saw the great ball. It almost filled the glade, reached nearly to the height of the trees. Gleaming gray-green it was, like the eyes of the wolf. The a.s.sociation made Karn pause. He drifted off to one side, picked a likely tree and hauled himself up into its lower branches.

Patience Karn had. He sat immobile, watchful. From inside this strange orb came sounds that were not too faint for Karn's keen hearing. An hour pa.s.sed; two hours. Nothing happened. Still he crouched, waiting.

His patience was rewarded. An opening appeared in the ball. There was a puff of air being released from pressure. A figure stepped through the opening and onto the earth. Another figure followed. What were they?

They were men! Clad in strange garments that covered them tightly, they walked upright on two legs. But what puny men!

Half Karn's size they were, and hairless. Through their skin-tight garments the bones of their narrow chests were visible. Their delicate fingers hovered at their waists over small sticks. The scent of fear was on them.

Karn's nose wrinkled in disgust. No danger here. Then a third figure stepped out into the light and Karn's flagging interest reawakened. This scent he recognized. This was a woman!

She was taller than the men and her garment clung tight to a rounded figure that brought a gleam to Karn's eyes. This one had hair, thicker than Karn's own. Her features were more delicate than those of the women he had known, but somehow more pleasing.

He realized that the three were speaking. Their mouths did not move, there was no sound. Yet they spoke. Karn could hear the voices inside his head. Somehow he understood.

"What a place to land," the woman said.

"Couldn't be helped," one of the men replied. "At least it has air. Once the tanks are full we'll be on our way again. In a minute or two I'll test that liquid to see if we can drink it."

"Must you test everything? It looks all right. And why must we stand so close to the s.h.i.+p?"

"Because we don't know what sort of place we've landed in," the second man said.

"There's only one way to find out," she told him. "By moving around."

Her tone was openly contemptuous. Karn found himself agreeing with her. These men were spineless. They must be so to let a woman talk to them like this. Listen to the way they bickered. Like three women over a piece of meat that had fallen from the cave fire.

Karn's nose twitched. What was wrong with these people? While they argued senselessly among themselves their lives hung in the balance. Couldn't they smell the gray wolf that was creeping toward them?

The three stood almost below Karn and jabbered back and forth. And not twenty feet away gray-green eyes watched them intently. Karn saw the wolf's haunches lower. In a moment three hundred and fifty pounds of carnivore would launch itself upon them.

Claws would rip their flesh, flas.h.i.+ng fangs rend and tear them. Karn was quite objective as he thought about it. They didn't have a chance.

A roar split the air. Karn had known it was coming. But the three below were taken completely by surprise. Fear rooted them and froze them into immobility. Crouching, Karn watched death come hurtling toward them.

But after all, they were his own kind.

Karn met the wolf in mid-leap. No tiger could have made the leap more surely than he. His plummeting weight landed squarely athwart the beast's back, breaking short the trajectory of its bound.

Together they crashed to earth. Karn's legs encircled the wolf's middle with the strength of a python. Steel fingers found its throat.

Claws raked at Karn's thighs, slavering fangs sought his hands. He retaliated in kind. His own teeth were at the wolf's jugular. The animal rolled, taking Karn along with him, but the man would not loose his grip.

b.e.s.t.i.a.l growls rumbled from two chests. Dust-covered and splattered with gore, they fought across the glade. Karn's legs tightened inexorably and the wolf's growl became an anguished squeal.

It could not shake the thing that clung to its back. Slowly, surely its ribs were forced inward until they cracked. Then jagged ends dug at its lungs, its heart. There was a gush of blood from its nostrils. It lay still.

Karn spat out the salt sweat that ran into his mouth and wiped it from his eyes. Slowly he rose and shook the tension from his leg muscles. Blood dripped from a shallow gash in his thigh but that concerned him little. He had suffered worse in the past.

For the duration of the fight he had forgotten completely the two men and the woman. Now, turning, he saw them watching him. Fear clouded the eyes of the men, but in the woman's gaze he read awed admiration.

Karn gestured, a motion meant to show peaceful intentions. His move was misinterpreted, and as he came toward the three the men reached for the little sticks that hung at their waists. Frantically they waved them at him.

Were they trying to frighten him with those things? Anger flushed Karn's face and a low growl issued from his throat. One blow from each of his hands and these puny men would be dead. The woman he liked.

But the sticks had stopped waving. They were pointing directly at him. He was caught suddenly in the grip of a force that held him helpless. Muscles stood out on his neck like tree roots but he could not move.

Inside his head Karn heard the woman arguing again with her two companions.

"A fine way to treat someone who's just saved our lives!"

"But he might be dangerous. You saw what he did to that beast. Look at the size of him. One twist of those hands and he'd tear our heads off our shoulders."

"He is a powerful brute, isn't he?" But there was no fear in her voice. Only admiration.

"Worse than a Green One," agreed the second of the hairless ones. "We'd better get back into the s.h.i.+p."

They were a little slow about that, Karn thought. In the underbrush close by he had heard the movements of a heavy body. A saber-tooth had no need for stealth. And it was coming their way.

"He's trying to tell us something," the woman was saying. "He may be trying to warn us. Turn off those rays."

The men hesitated. Then their fingers moved slightly and Karn was free to move.

But now there was no time for warnings. Karn gestured over his shoulder and started for the opening in the huge ball. He sensed that safety lay inside. Behind him a huge cat snarled.

The hairless ones hesitated no longer. Leaving the woman to her own devices they dashed for the s.h.i.+p. She turned to run, tripped and fell. Karn scooped her up as he ran.

Almost together, the four reached the s.h.i.+p. The smell of the saber-tooth was strong in Karn's nostrils; he could almost feel its breath on his neck as he dashed up a ramp.

One of the men was fumbling with a lever. The ramp swung up; the opening in the s.h.i.+p's side vanished. Against the gray-green wall the tiger's body thudded.

That danger now behind them, the two men were pointing their sticks at Karn again. But this time the woman halted them before they could paralyze him.

"That's twice he's saved our lives. How much more proof do we need that he's friendly?" She smiled at Karn. "Who are you?"

"Karn, of the tribe of Tur."

"I am Andra, and these men are Harus and Ven. We are of Mahlo. We thank you for saving our lives."

Harus was the smaller of the two men. His face was thin, pinched with perpetual fear. Ven too seemed always frightened. They stared at Karn doubtfully.

"What are we going to do with him?" Harus asked.

"Maybe we could take him back to his tribe," Andra suggested. "If it's very far we could save him a long trip."

Her eyes questioned Karn. He shook his head.

"No. They would kill me."

"Somewhere else, then?"

Karn shrugged. A full-grown male was no welcome guest in any tribe. Andra read his thoughts and was sympathetic.

"You're really up against it, aren't you? From what we've seen of your world so far I would guess it was no place for a man without friends."

"I will go with you to your people; to Mahlo, wherever that is."

"What a notion," Harus snorted. "Picture this uncouth thing in his wolf skin on Mahlo! Besides" and the disdain went out of his voice, "we'd be doing him no favor."

Karn grunted. They didn't think much of him. But there was more of it than that. The three of them had fallen to arguing again. There was talk of Mahlo and the Green Ones, whoever they were. The argument droned on endlessly.

"Too much talk," Karn said abruptly.

The talk stopped. Andra was looking at Karn, a slow smile spreading across her face. Her b.r.e.a.s.t.s rose and fell with a change in her breathing and Karn felt a warm flush rise within him.

"I think Karn is right," she said. "Too much talk."

Somewhere in the bowels of the s.h.i.+p a great beast purred. I should not have let them strap me down, Karn thought. The purring grew louder, the s.h.i.+p lifted.

His back pressed against the seat and there was a crus.h.i.+ng weight on his chest. His insides tied themselves in knots. What was happening to him. What invisible monster held him in its clutch?

"Afraid?" Andra asked.

Karn was aware that the weight was off his chest. The purring was m.u.f.fled. They had the beast penned. Then Andra unfastened the thongs that bound Karn.

"Why should Karn be afraid?" he smiled scornfully.

"Perhaps now you would rather remain in your own world. There may be danger on Mahlo."

This woman was a fool. Naturally; she was a woman. What was danger to Karn? What was danger to a man who had lived his life with Tur and the bull males of the tribe, who roamed the same jungle with the saber-tooth and the great wolf?

Yet she was a woman, and one who attracted him. Karn reached out and drew her to him. Let her feel the might of his arms. She was doing something strange with her lips, pressing them against his.

"Now let me go," she said. Then, sharply, "Let me go!"

Bewildered, Karn released his grip. He was confused by this creature of moods. One moment she smiled and the next moment she seemed angry. He wanted to please her. But how?

"Well, we're all right," Ven said. He came from some other chamber in the great s.h.i.+p. "We're running free now. At the next force field we'll cut into Mahlo's...o...b..t."

There was more strange talk which Karn did not understand. More debate, too. It seemed that these men spent half their time arguing with the woman.

Apparently the men held the supremacy, but a very shaky one. The woman seemed not to know too much about this s.h.i.+p. But she had a good deal to say nevertheless.

Then Harus' voice came out of nowhere. "Better strap in again. We've hit Mahlo's...o...b..t."

Again there was the awful pressure, the crus.h.i.+ng weight. Violent forces shook the s.h.i.+p. Andra moaned softly. Strange words issued from her lips. Then they were out of the clutch of the awful force.

"Landing at n.o.bla," Ven said. Panels slid away and Karn could see through the walls of the s.h.i.+p.

Below them was a city. They dropped toward it and its gargoyle-topped towers reached up to meet them. Strange birds winged across an azure sky. They came down over the city and landed gently in a meadow next to the mouth of a great cavern.

"n.o.body around," Ven said. "I don't understand it."

"They weren't expecting us to land at n.o.bla," Andra said. "You're always worrying about something. Come on, let's get out."

The ramp came down and the four descended, Harus leading the way. Karn wondered why they moved so warily. This was their own land. What were they afraid of?