WHEN TIME ROLLED BACK

Long before Rog found the mysterious, shining ball back in the mountains, he knew he was far different from the rest of his tribe that lived along the river. He knew it because he didn't think the same way they did, and because there was a difference even in their appearance.

Sarak, who was the Old Man of the tribe as well as his sire, and Monah, Rog's mother, were short and heavy and thickly covered with hair. Rog was taller and straighter, and endowed with much less hair. Too, his face was much broader through the cheekbones and less heavy-looking around the mouth. There was only one other in the tribe who seemed to be of the same physical cast as Rog, and that was Lo, a young woman who dwelt with her family in Sarak's cave.

Though the stalwart, blond young man took an active part in all the work of the tribe—hunting, skinning, tool-making—there were times when he would detach himself from the rest as though he were a creature of a higher world viewing a savage orgy.

Such a time was the delirious madness of eating after the lucky kill of a giant mammoth. All the able-bodied men of the tribe would aid in dragging the great, quiet animal into the clearing beside the river, and then, to the cries of men, women, and children, huge hunks of flesh would be torn off and devoured by all. The orgy did not cease until no one was able to stand without falling.

But Rog and Lo would stand back in the shadows and watch gravely, gnawing passively on smaller pieces of meat.

The others of the tribe realized that Rog and Lo were somehow different from them. And because of the young man's tremendous strength and because he was the son of the Old Man, he was not molested. But secretly the slow-thinking men and women classed him with Ta, the half-witted boy who sat all day playing with a stick.

None of them, not even the thoughtful Lo, ever stopped to wonder how far back their ancestors had lived in this spot. Nor did they care. But Rog found himself wondering if life had always been like this, or if it had once been superior or inferior to their mode of life. Sometimes he would grow curious enough to wander far down the river, or off into the hills, alone.

It was on one of those excursions, prompted by an increasing dissatisfaction with the life of the tribe, that Rog wandered back four or five ranges from the cave dwellings. He had just sat down to eat some of the dried meat he had brought along when his eye was caught by a glint of flashing metal off through the dense woods.

Startled, he leaped up and made his way nearer. Within ten minutes he was standing aghast, staring at a great, gleaming globe of silver, half buried in the soft, moldy ground. He was terrified, for an instant, and broke into panic-stricken flight before this thing that none of the aborigines had ever seen. Then Rog's overpowering curiosity brought him creeping back.

It was fifty times as tall as he was, just the half of it he could see. It sparkled in the sunlight like white fire. Then, down near the ground, Rog saw a round cut in the smooth surface. Something told him this was the way inside the ball, though there was no reason why he should not have believed it was anything but solid. But there was an inner urge that made him approach gingerly and take hold of the long cross-bar that was set into the door.

Eagerly he pulled at it. Nothing happened. He pushed, twisted, shoved, and still the thing would not budge. Then a gleam of comprehension flickered in his eyes. He grasped both ends of the bar and turned it the way a plumber turns a pipe-cutter. It moved!

The round entrance swivelled about on threads that were glass-smooth, until suddenly it swung aside on a hinge. Rog gasped and poked his head inside. He was so amazed that for a couple of minutes he could only stand in the portal, gaping.

The ball was divided into floors, apparently, for there was a spiral staircase in the middle that went up through the high ceiling, and a continuation of the stairway going down into the lower half of it. From some small globes hanging from the ceiling a soft radiation was thrown into the room. There were gleaming tables and cabinets and shelves of mystifying apparatus that Rog's eyes had never seen.

At last he ventured inside. He went from one glass-covered table to the next, frowning at the things he saw. He could make nothing of them.

There were twenty tables, and each bore a maze of strange symbols on its top. He was at a loss to divine what they meant, until he discovered that at the bottom of each chart there was a picture of a globe, with a tiny red arrow pointing to a section of it. Then he knew. The tables were supposed to tell him what was to be found on each floor.

All this Rog knew, although he had never seen metal before, or glass, or heard of a floor. But somehow he felt more at home in here than he did in the cave with Sarak and Monah. With perfect confidence he went to the staircase and climbed to the first floor.

A low, shining fence leading from the stairway made it plain that he was to follow inside it and view each exhibit as he went. Rog went to the first table, and within five minutes he was plunged into a maze of conjectures and mysteries that made his aboriginal brain ache.

The first table bore a number of short groups of symbols, completely lost on him. There were flowing, cursive characters; then a line of wedge-shaped pictures; line after line of characters differing only slightly; and finally, at the very bottom, something he could understand.

There was pictured a figure that brought a quick smile of apprehension to Rog's face—an old man, bowed with age. Beside him was a young child, enclosed in a red circle that set him off from the old man. A word leaped to his lips.... Not, perhaps, the word that the artist had intended, but close enough.

"Beginning!" was the thought that came from his lips.

After that the messages in the words and pictures made more sense to him. Stupefied, trembling with excitement at this thing that was happening to him, he went on and on.

He ignored the symbols as mere decorations, and read the pictures, hurrying from one group to the next. He stared long and amazed at amazingly life-like representations of the life of a tribe such as his own. The men and women even looked like his did—short, squat, hairy. The scenes showed them killing great animals somewhat similar to the ones on whose meat they lived, portrayed them chipping flint holes, and doing the other dozens of things life demanded of them.

But as he went on the life changed.

From cave-houses the migration was to peculiar dwellings of poles and boughs, making box-like affairs in which men and women lived. The tribe-folk, even, changed. They grew more upright and less hairy, and their faces looked something like the reflection that stared back at Rog from quiet forest pools.

The message of the pictures did not by any means unfold fully to Rog, but from the chain of scenes he began to grasp something. Life steadily became more and more complex, as though it were working toward something—with a purpose. Men grew taller, their dwellings bigger, their weapons stranger and apparently more efficient. He saw small tribal conflicts broaden into great wars between numbers of tribes.

He gaped at inventions which he could not begin to comprehend. Before his startled gaze caves gave way to great dwelling-places so large that men looked like ants beside them. He had to smile at the fanciful picturization of a man flying through the air in a fantastic machine. But as Rog neared the end of the exhibit, he realized that the story, if story it was, did not satisfy him.

In his crude, barbaric way, he had great visions of improving life so that death was not such a stern, everpresent reality, and men would have time for things other than eating and sleeping and mating. He was a philosopher, if such a thing were conceivable of a man who lived on raw meat. And this story did not appeal to him, for as far as he could tell men grew more and more dissatisfied, instead of contented....

Terrible wars were shown to him. Violent death stalked the streets of the beautiful cities. War after war piled on top of struggling civilization until at last a conflict that seemed to embrace every shred of man's life took place. After that there were scenes of cities utterly deserted, crumbling into ruins. The final picture made Rog gasp with shock.

They showed ten men laboring on a great steel ball, filling it with tiny miniatures and statues and boxes. The last picture was of one man lying under a transparent glass dome at the bottom of the ball.

Rog was suddenly frightened. He turned and fled back down the stairs and out the door, and plunged into the forest—

He said nothing to the rest of the tribe that day. Somehow he knew he must guard his secret with his life. If the others found what he had discovered, they would crowd into it and tear to shreds these things that he treasured, simply through love of destruction. When he thought of that, his fists clenched and hatred blazed in his eyes. The ball must be kept safe, so that he could learn what it meant. It meant more than life itself, more than Lo, even, that he should solve the message in the shining globe.

But the next day he found time to sit by the river with Lo. "You were gone yesterday," she said. "Where?"

Rog's heart leaped into his mouth. He looked down in sudden confusion. "Only down the river," he lied. "I went to hunt roots."

Her questioning eyes told him she knew he was lying. But she was wise, and held her tongue.

After a long time he could hold himself in no longer. "Do you ever wonder," he asked intensely, "why we live this way? I mean—have men always lived like this, in caves, killing their meat and gorging themselves on it, and then starving until they killed again?"

Lo's dark eyes met his boring glance, but she said nothing. She was feminine enough, and civilized enough, to realize it wasn't an answer he wanted, but an audience.

In a moment he went on. "You and I aren't like the others, Lo. The Old Man and all the rest of the people aren't happy unless they are eating. But we can be happy talking, and ... wondering."

She smiled at him in happy understanding. "Luk-no says you are lazy," she said naïvely. "But I know you work hard even when you are quiet. Else how would you find things to make like the Thing that Floats?"

He warmed at her mention of his raft. It was only a short while ago that he had conceived the idea of tying a bundle of logs together to ferry things across the river, but now it was in daily use. But when his mind rested on Luk-no, he scowled.

"Some day I will kill him," he promised savagely. "Always he interferes."

Luk-no was a great, stubby trunk of a man who resented Lo's interest in Rog and took every chance to get in his way. His greatest delight was to carry tales of his laziness to Sarak, who would promptly beat his son with a club. Such treatment rankled under Rog's skin.

Then he forgot his hatred of the black-browed one in contemplation of other things. "I do not like the way we live," he said simply. "Our caves are cold and sometimes wet. Our weapons are scarcely able to kill the animals we need before they kill us. I do not like the way the Old Man rules us, telling us what we can do and what we cannot do. Why shouldn't I make better things for myself if I want, instead of being beaten for not working? Some day...."

Lo caught up the thread of thought quickly. "I know," she nodded. "Some day you will challenge Sarak and kill him. Then you will be the Old Man! You will be the one who rules!"

"So that is what you two talk of! I knew it was not how to get food for the tribe!" The voice was triumphant and harsh, close behind them.

They were on their feet in an instant, whirling to face the brutally-built man who had come up behind them. It was Luk-no. His little red-rimmed eyes were alight with anticipation.

"You came at the wrong moment," Rog growled sullenly. "We were not talking of that, but Lo grew over-enthusiastic."

"Well, and won't the Old Man be glad to hear this?" Luk-no taunted. "When I tell him, he will cave your head in like an acorn."

Rog's face was black with fury. "If you tell Sarak what you heard," he said tensely, "I will take your dirty throat in my hands and break it. Then I'll gouge your prying eyes out. I'll tear your tongue out so you can never tell anything else you hear again. Or perhaps I will just do it now!" He took a menacing step towards the smaller, burlier man, his club resting on his shoulder.

Luk-no cringed, essaying a grin. "You are too quick to anger!" he protested. "It was a joke."

"A joke," Rog mocked. "Like the time you toppled a rock on the head of one of the others who wished to mate with Lo! I don't like your jokes, dirty one. Go back to your caterpillar-grubbing before I change my mind."

But as Luk-no slunk away, he felt icy chills run down his back. He must be more careful! Here he had been on the point of telling everything to Lo. What would have resulted if Luk-no had heard! The globe, perhaps, would have been discovered and ruined!

And Rog, stalking away by himself, knew that he must be triply careful, for somehow he sensed that in that shining ball was contained the whole future of the tribe....

In the weeks to come he made many trips back to the sphere. With every visit his wonder grew.

By intuition and study he became convinced that the place was a repository in which some race long dead—a "tribe" was his only word for them—had sought to preserve the knowledge of their civilization for those to come later. His agile mind told him why it had been necessary.

Mankind had worked itself up to the point where it had too much leisure, and turned its energy to the destruction of others. The inevitable result was self-destruction. But the ten he had seen in the pictures stole away and created this museum of history and science, to aid mankind when it must again struggle upward.

Under Luk-no's subtle whispering the tribe grew incensed against Rog and watched him constantly, seeking to learn where he went on the days he was absent. They resented the things he "invented" with such regularity. Little did they realize he was but copying things he saw in the sphere.

The thing that astounded them most, even Rog himself, was the wheel.

He hacked a section of a log into a rough cylinder about three feet thick and bored a hole through it for an axle. Two of these "wheels" he joined together by a peeled pole and made a crude sort of cart, more, perhaps, like a wheelbarrow. But the simple contraption did the work of many men in hauling rocks and meat. Had it not been for the tremendous jealousy it aroused among other young men in the settlement, he would have been acclaimed a hero.

Another day he fashioned a device consisting of a bent stick held in a permanent arc by a piece of rawhide. When a notched branch, skinned clean of bark and twigs, was launched by the bowstring, it flew with sufficient force to kill a squirrel. Rog was as delighted as a child with his bow and arrow, and spent many hours practicing with it.

There were other things in the museum that brought deep lines to his forehead. He was already beginning to comprehend the principle of the water-wheel and the pulley, but when he saw a man hanging from a great bag high in the air, or a hunter killing a bear by pointing a smoking stick at it, he was stupefied.

Just six weeks after his discovery of the ball, he found something that froze him with sheer terror, that sent him running away, vowing never to return.

On this day he had gone down the stairs through a number of floors, until he came to a room in the very bottom of the sphere. The door to the chamber was closed. It was an unusual door, of a gleaming material that made him blink, and had a single character in the center of it: a red circle from which a small sector had been removed. The sector hovered over the gap, as if asking to be replaced.

Rog pushed the door open and went in, suddenly stopped. His face froze, then brightened with eagerness. Hastily he went to the bubble-like dome of glass in the middle of the room.

Then he was standing rigid with shock. On a low couch under the glass bell lay an old man clad in flowing, white garments. But he was different from the tribe's old men. He was taller and frailer. His brow was lofty, instead of being crowded down over his eyebrows, and his expression was serene in death.

Rog shoved his nose against the glass, studying the dignified figure. He wished, suddenly, that the old man were not dead, for he could undoubtedly explain all these things to him that had him puzzling so hopelessly. At last his gaze wandered to the maze of machines at the head of the couch.

There was nothing there that he could begin to understand. Just a battery of glass and metal and tubes. Two red wires led from the machinery to a board on which were a number of dials and things that Rog scarcely gave a second glance.

Then, all at once, he stiffened. His eyes fastened on a shining red circle of metal, exactly the same as the symbol on the door. And there was a section out of it, lying there asking him to put it back in!

Now he went to it and lifted the heavy little bit of red stuff. It had prongs that fitted into corresponding holes in the rest of the circle which was firmly fixed to the board. Rog knew he was supposed to shove the sector into place. His fingers were trembling as he hesitated. Suddenly he bent forward and pushed the prongs home!

Suddenly Rog bent forward and shoved the prongs home.

There was an instant of utter silence. His primitive mind told him that this was a moment of moments, though he knew not why. Gradually a low humming told him his action had taken results. The machinery glowed and wheels began to turn slowly, then faster and faster, until they were spinning discs of silver.

Rog's eyes fastened on the ancient's face. Why, he did not know. Perhaps he was asking him to answer.... He scowled. Were his eyes deceiving him, or had the placid white face become flushed?

"Agh!" A hoarse bark of terror burst from Rog's throat. The old man's eyes were open and he was looking straight at him!

The young aborigine had seen enough. He turned and fled, caring for nothing but his own life now.

For a week he was afraid even to think of what he had seen. His mind was outraged by the thought of the dead returning to life.

He worked so hard with the tribe now that they were amazed at the change in him. It was growing on towards winter, and stores of roots, edible weeds, and dried meat were crowded into the smoky, dark caves in which they lived. The winters had been growing so heavy that the Old Man had even mentioned moving farther south, where they had observed birds and certain animals went in cold weather. This winter they were taking no chance of starving. Great supplies of food were being put in long ahead of time.

But in spite of Rog's industry, Luk-no found time to run him down, secretly, to Sarak. The two of them would mumble between themselves, Luk-no furtive and prattling, the Old Man smoldering with righteous indignation. And presently the Old Man, who was actually only about fifteen years older than Rog, would take it upon himself to chastise him. His great, bulging muscles would strain as he cudgelled him.

Rog sweltered under the mistreatment ... but this trouble was as nothing compared to the burning curiosity to know what he had done the last time he went to the globe. Even Lo could not be let in on such a secret. She, too, would class him with Ta, then.

The day came when he could stand it no longer.

Almost without his own volition he found himself far back in the hills, making swiftly towards the museum. He did not rush in as heretofore when he reached it. He crept up and poked his head inside the portal, wide-eyed and breathing hard. There was the sound of a twig's breaking behind him, and he whirled, flattening out against the wall.

"Do not be afraid." It was the smiling patriarch who spoke. "I am Johann Adam, the man you restored to life. I am here to help you."

But Rog could not understand the strange, musical sounds he made. He continued to crouch there, waiting.

The old man spread his hands. "I have slept long, if you represent man of today. But follow me." And he gestured to the boy, passing on into the sphere.

Then there followed an hour of the most thrilling, most baffling, conversation he had ever known. Johann Adam took a big pad and a writing-stick and made picture after picture, while Rog crouched near him, fearing to stay, and yet hating the thought of missing anything by leaving. The first time Adam extended the pad to him to see what he had written, he shrank back and almost ran away.

Somehow he knew that it was ridiculous, his being afraid of a man so much feebler than he, and he stiffened his feeble courage. But there was a tiny voice inside him that whispered that the ancient had a power that transcended that of mere muscles. Rog remembered the smoking sticks that killed bears....

Finally he glanced at the pad, and then took it. The diagram was a repetition of the old man and child in the chart in the room above. A smile claimed his features. He pointed upward and gave the pad back.

Adam was pleased. He seemed to inventory Rog's quick eyes and his smooth, broad brow. Then he was writing again. The younger man's fear broke down completely under the force of his desire for learning. Within a few minutes he was sitting on the floor beside Johann Adam, nodding and grinning and sometimes frowning in puzzlement. But a story was unfolding to him. He was learning how the sphere happened to be.

Laboriously he pieced together the fact that Adam and nine other men had foreseen what was to happen to the earth and its super-civilization. Knowing that destruction of modern culture was on the way, they had sought to preserve some part of it for humanity when—and if—men emerged from the darkness at some future time.

They had constructed the globe and filled it with every scrap of knowledge known to man. Then they constructed the last room of all, the chamber in which Adam was to lie awaiting the renewal of his suspended life, or the death that would be complete.

On the eve of the last of the terrible, cataclysmic wars that burned mankind from earth like a searing flame from outer space, Johann Adam entered the globe and the others went back, to die.

Their supposition had been correct. The last great invention of the war gods, a corrosive gas, had got out of control. Within a space of years men were wiped from the face of earth.

What happened then Adam could not say. Perhaps man had struggled up from the bottom of evolution's ladder again; perhaps a tribe of high-type apes had been left after the catastrophe, and were now Rog's people, developed by a few thousand years. At any rate, the world was again stumbling through the dark shadows of the Stone Age. And from that murky period civilization was slowly crawling back to its former golden age.

And Rog knew who would take the lead in the advance. He himself, under the guidance of Johann Adam, would be the Old Man of all Old Men! He would be instrumental in leading his people away from the paths that would deter their progress. All this he would do, with Lo at his side!

He took the drawing-stick himself, then, and made what crude signs he could to tell of the strained conditions at the caves. Adam frowned and nodded slowly. Clearly he was worried. The death of this man, whom he knew was hundreds of years ahead of his time, might nullify all his chances of aiding the world.

Then a gleam of hope lighted his eyes. By pictures he showed Rog what to do. He was to bring Lo with him and stay here in the globe until he had learned enough to be able to convince the tribe of his superiority. Until the day when he must be recognized as the leader of them all!

He was reluctant to leave Adam, and yet eager to carry out his instructions. Trembling with anticipation, he took his clumsy club over his shoulder and ran back through the trees towards the river....

He came back to the caves to find an angry group awaiting him. Sarak stood at the entrance to the cave, leaning on his club. He was an imposing figure in his anger. His sloping shoulders bulged massively under a mat of black hair, and his short body was tight with muscles drawn hard by hatred.

"Sluggard!" he spat at Rog. "You run off and hide, do you, while others work? Already black clouds gather, but you let old men and women, as well as the younger ones, find food to keep the fat on your bones during the long winter."

Rog stiffened with anxiety. He saw Lo watching him wide-eyed and white of face, and realized Luk-no was grinning at his predicament. He decided on a bold lie. "I was stalking a deer," he said. "I followed it far into the hills, but could not get close enough to kill it. Had I succeeded, it would have fed more mouths than what roots I could have gathered."

The Old Man snorted. "You do not even lie well," he snarled. "You carry only a club. Did you think to get close enough to kill it with that?" His close-set, red-rimmed eyes blazed. "Where is your spear?"

"I—I lost it," Rog faltered.

"Lost it, did you?" shouted Sarak. "Well, I have not lost my club, smooth-faced one! Feel its anger, now, and remember, when you feel like sleeping in the forest instead of working."

His wide mouth was distorted, baring ugly black snags of teeth as he advanced. The thick cudgel, weighted with a stone, came up over his head.

For a moment Rog considered springing in to battle. His mind weighed his chances. Against Sarak, perhaps, he might have had a chance of coming out alive, but the tribe was incensed against him now. Luk-no would lead them against him should he vanquish the bloodthirsty Old Man.

Then blows were raining down upon his head and back. As best he could, he warded them off with his club, but the blood sprang from half a dozen wounds in the first few seconds. He went to his knees, dazed and bleeding. Sarak shouted and screamed and danced, in savage enjoyment of his tribal right to punish, justifiably or not. His thick lips gleamed with saliva.

And Rog bit his lip against the pain and bore it. He ground down the hate welling up within his breast, because he must come out of this alive. Whatever it cost him, he must endure it, or the secret of the museum might die with Johann Adam. A bitter laugh was torn from his lips at the thought that his only motive in living was to help the tribe!

The wall of leering faces swam before his vision. The ruler's countenance loomed before them all, twisted with savagery. His breathing was stertorous, rasping through clenched teeth. At last Rog could stand no more. The club fell from his hands and he sprawled on his face in the cavern.

Sometime during the night he awoke. His body was a mass of bruises and cuts. It gave him excruciating agony to force his head from the floor, but he did so, and cast a slow glance about him. Then he saw what he wanted.

Painfully he inched himself to Lo's side and aroused her, placing his hand quickly over her mouth to stifle the outcry. "It's me," he whispered. "Rog. Listen to me, Lo. I want you to go away with me!"

Instantly the girl was wide awake. "Go away!" she echoed.

He nodded. "Not for good. Just for a few moons. Then we will come back, and I will become the Old Man!"

Now Lo was trembling with excitement. Before she could question him, he bent nearer and whispered, "Pay attention to what I say, but don't ask questions. We are going back into the forest, to a great, shining stone I found. And we must go tomorrow, as soon as the tribe is not noticing us."

Then, hurriedly, he told her of the sphere. She was puzzled, almost inclined to doubt him, but the energy and sincerity of his manner told her he was not lying. A groan from one of the sleepers sent him scuttling back to his place, to lie there sleepless until the sun came up and shot long, golden lances into the cave.

He was so tense in the morning that he could scarcely force himself to pretend to work. Lo stayed near him. Fear and hope battled within him. Failure now would mean that Johann Adam would wait in vain, out in the forest, for him to come back. He would know Rog could not help him, at last, and then ... what?

He would become older rapidly, for he had many years on his shoulders already. Time would almost surely cut him down before he could find anyone in any of the tribes intelligent enough to know he was not a devil. A cold sweat broke out on his forehead at the thought of so much knowledge being wasted. Though he could not know it, his concern for the secrets of the museum marked him as the first scientist in many thousands of years.

When the sun had climbed high over the tops of the leafy trees Rog saw his chance. The others had scattered, paying him little attention. In a flash he had darted to Lo's side and hissed, "Now! We must run fast!"

They crept to the edge of the clearing and then sprang into the thick, cool darkness of the underbrush. Under the swift feet the miles slipped past. Rog was tense and anxious, Lo eager as a child and a little frightened. She did not know what he did: That upon their reaching the sphere safely depended thousands of years of evolution.

And then, almost without warning, they were springing into the small circle of bare ground surrounding the shining ball of metal. They stopped just a few feet away from the closed door and stood hand in hand while Rog shouted.

After a moment the bar across the portal began to turn. Then it had swung open ... and in that same instant something took place that drained every drop of blood from Rog's face and left him shivering in dumb despair.

Not fifty feet behind them a confused shouting arose, and to their shocked gazes were revealed the running forms of a dozen of the tribesmen, led by Sarak, himself!

A groan of despair came from the lips of Johann Adam. Lo sank to the ground and waited for the clubs to end her life with that of Rog. But Rog was too stupefied to do or say anything. His club hung from nerveless fingers. The sight of twelve men rushing upon him seemed not to register in his mind.

Then he moved. The club swung up over one shoulder, and he stepped forward one pace. His words carried strongly across the intervening distance.

"Wait!" he shouted. "I would do battle with Sarak alone. One so weak and stupid as he has no right to rule!"

They stopped. It was a young man's right, if he were so foolish, to challenge the Old Man to battle. It meant that his wisdom and strength were questioned, and only by a battle to the death could it be settled. Sarak roared his acceptance, and the others were bound to wait.

He strode from the knot of savage tribesmen, cudgel lofted over his head. Taunts and threats crowded his flabby lips.

It was a daring move that Rog was making. Unless he challenged Sarak and demanded a fight alone with him, they would be massacred. Perhaps if he won, the tribe would still exact payment, for Luk-no was at the head of the men, waiting for his chance to avenge himself.

They crashed together with a sickening sound of stone on flesh. Blood spurted from Rog's head, where Sarak's club had grazed him. The sight of the blood brought a scream of triumph from the Old Man, he raised the weapon again in his stubby hands.

Rog released the club with his right hand and shot a hard fist into the other's face. Thrown off guard, Sarak had to fall back as his son swept in upon him. His years of experience saved him as he warded off every blow expertly. He drove in a hard sweep of the cudgel that rocked against the younger man's shoulder.

Again Sarak bludgeoned his way in, driving Rog back before him, bleeding and dazed. A sob of despair choked Rog. It was more than his life that was at stake today.

Johann Adam's fingers were locked in the folds of his garments as he watched the struggle. He knew as well as Rog what the stakes were. And it was a heartbreaking fact for him to realize that he was powerless to help. Interference by him, even if it resulted in victory for the boy, would mean the tribe would never accept him. Only as a tribal member could he aid.

Around the fighters a great crowd was collecting. The rest of the tribe had run up just after Sarak and Luk-no, and now they crowded in to watch the deadly combat. Their screams of hate filled the quiet forest.

Rog fought with desperation. In strength he was a match for his bloodthirsty sire, but he lacked the years of experience behind the Old Man's clubbing. He was forced to give ground time after time, wading in with swinging bludgeon only to be brought to his knees by a clever blow over the back of the neck.

Sweat streamed down his forehead and blinded him, mingling with blood. His ribs ached terribly from a blow that had cracked several on one side, and one leg was wrenched so it would hardly support him. But still his shoulders writhed to his efforts to give Sarak a death blow.

Suddenly, as he backed to the very edge of the crowd, he saw a shadow rise swiftly over his head, in the black images cast on the ground. For a moment the battle with Sarak was forgotten in the more immediate danger of being clubbed from behind. He ducked.

Something smacked into the ground at his feet, and a man, his balance lost by the blow's missing, lunged past. Luk-no stumbled over the boulder that had almost cost Rog his life. In a flash the intended victim's club was raised and brought down on his back. With a scream of pain the black-browed one went down.

The Old Man had not been napping. As Rog's attention wavered he leaped in close and pulled his cudgel around behind him for a vicious roundhouse swipe that would crush his adversary's head. Rog's only warning was his hissing breath. He squatted down quickly, just as the stone swept over him, so close it raised the hackles on his neck.

In the next moment Rog's chance came. Sarak lunged off balance and twisted desperately around to recover it. Rog took one deep breath ... and then he leaped.

His club hissed through the air as he put all his force into a final effort. There was a solid crunching sound as the sharp rock connected with Sarak's skull. The Old Man went down without a sound, and he was Old Man no longer....

In the moment's hush that fell over the group, Rog went swiftly back to Lo and Johann Adam. He stood between them and raised both arms for attention.

"Is there any other who wishes to be ruler?" he shouted.

There was not a sound. Luk-no crouched where he had fallen.

A glad tide rushed up in Rog's breast. He had won! He was the Old Man now, himself, free to do as he wished, and with the power to make the tribe do what he knew was best for them. He spoke once more.

"Then, know this—I am your ruler and you are my people. But this old man beside me is far wiser than any of us. You will follow my wishes—I will follow his. You do not know what this means now, but you will later."

A few feet away the hapless Luk-no still crouched and awaited the death blow that was his due. Then Rog performed the first act of mercy mankind had known in many hundreds of years.

Sharply he said to him, "Get up. I will not kill you because I do not deign to dirty my club with your blood. But if ever you interfere with me or my mate or the old one, it will go hard with you."

Luk-no crept away, while amazement gripped the tribe. And in the eyes of the men and women Rog read complete victory.

Johann Adam shook his wise old head, realizing what had happened. "I have known men far more cultured than you to seize the opportunity you spurned," he murmured. "Perhaps with such a start, civilization will come to a better end, this time!"