DESTROYER OF WORLDS.

BY LARRY NIVEN.

PROLOGUE.

1.

Intelligence was overrated.

Not unimportant, merely not the everything everything that many made intelligence out to be. Intelligence leapt instantly, inexorably, from the merest observation to subtle implication to profound deduction to utter certainty. Intelligence laid bare the threats, vulnerabilities, and opportunities that lurked everywhere. Intelligence understood that other minds all around raced to similar conclusions- that many made intelligence out to be. Intelligence leapt instantly, inexorably, from the merest observation to subtle implication to profound deduction to utter certainty. Intelligence laid bare the threats, vulnerabilities, and opportunities that lurked everywhere. Intelligence understood that other minds all around raced to similar conclusions- And that countless rivals would take immediate action thereon.

To become a protector, awakening into intelligence, was to lose all innocence, and with it the ability ever to let down one's guard.

But here, now, so very very far from home, things were different. far from home, things were different.

Thssthfok stood alone atop a glacial vastness, clad only in a thin vest, worn for its pockets rather than for warmth. His hard, leathery skin was proof against the cold, at least for short periods. A portable shelter stood a few steps away, his shuttlecraft not much more distant.

The air was clean and crisp and bland in his nostrils. The oceans of this pristine world teemed with life, mostly single-celled, but the land remained barren. There were no native predators to fear here. As for protectors, the most formidable of predators, within a day-tenth's travel, there was only himself.

The children and breeders Thssthfok lived to protect were all on Pakhome, incommunicably distant. Their safety had been entrusted to kin and further guaranteed, to the extent that was possible, with hostages, promised rewards, and dire threats. Without such measures, Thssthfok could never have come. That would have been unfortunate, for if this mission succeeded, all all in clan Rilchuk might enjoy the greatest possible protection- in clan Rilchuk might enjoy the greatest possible protection- Release from the endless wars of Pakhome.

The only sound, but for the wind, was the whir of powerful electric motors laboring to extract deep core samples. Locked into the glacier was a story eons in the making, written in layers of ice, traces of ash, and microscopic bubbles of trapped gases.

Thssthfok was here to read it.

The concentrations of trapped gases would speak of the evolving climate. The traces of ash would reveal the frequency of volcanic eruptions. Occasional dustings of rare metals like iridium would disclose the impacts of large meteors. Patterns in the thickness of layers would speak to fluctuations in ocean volume and worldwide ice cover. That information, and the detailed observations of newly emplaced satellites, and the measured orbital parameters of this world ... together they would reveal much about the long-term suitability of this place.

For this world offered far more temperate climes. Suitably prepared, much of the land here might be as pleasant as the great savannahs on which the Pak had evolved-if present conditions persisted. Planetary engineering took time and great resources. To relocate the entire clan-hundreds of protectors and many thousand children and breeders-would be a ma.s.sive undertaking. Thssthfok had crossed a hundred light-years to answer a single question: How variable was the climate here? present conditions persisted. Planetary engineering took time and great resources. To relocate the entire clan-hundreds of protectors and many thousand children and breeders-would be a ma.s.sive undertaking. Thssthfok had crossed a hundred light-years to answer a single question: How variable was the climate here?

He needed core samples, drilling as far back in time as he could get. A climate forecast rooted only in today's data was no more than a guess, and no basis for casting the fate of everything he held dear. The ice would yield its secrets, but the ice refused to be rushed... .

And so, remote from danger, removed from any clues to the circ.u.mstances of his breeders, Thssthfok was safe. Safe-unlike almost anywhere, anytime, on Pakhome-to disregard the outside world. Safe to ignore past and future. Safe to immerse himself, unprotectorlike, in an unending present. Safe to return to an age before thought.

Safe to dream of his time as a breeder ...

THSSTHFOK REMEMBERED.

He remembered hunting and mating and fighting and exploring, always with zest. He remembered being curious about everything and understanding almost nothing. He remembered his pride in the ability to fashion a pitiful few tools: sharpened sticks, chipped-stone implements, straps cut from cured animal hide. He remembered staring, awestruck, into campfires. He remembered conversing with family-if the concepts expressible in a few hundred grunts and gestures could be called conversation.

The world then was ever new and exciting and usually inexplicable. Sometimes, when people died, a reason was obvious: torn by wild beasts, or fallen from a great height, or impaled on a spear. But many deaths came without warning or reason, with only the onset of bad scents to explain.

For scent was everything: how one found or avoided one's enemies; how one bonded with one's family; how one was drawn to mates and knew one's own children.

He remembered the rich, warm scent of family. Every person had a unique smell, and yet the subtleties of that aroma declared one's lineage for generations. He was not called Thssthfok then. There were were no names, for names were not necessary. To smell relationships sufficed. no names, for names were not necessary. To smell relationships sufficed.

Scent was everything, and death was everywhere, and life- Life was intense.

Lightning and starlight, seasons and tides, the ways of beasts and the wants of the mysterious beings occasionally glimpsed at a distance (and even less often, intervening) ... all were unfathomable and wondrous.

For all their poignancy and grip, those memories were indistinct. A breeder merely dipped a toe into the great sea of sapience.

And then, one day, as happened to all breeders who reached a suitable age, he smelled ...

Heaven.

Heaven was another vague concept for breeders. As they threw rocks and spears, so, obviously, far mightier beings hurled the lightning. Who but G.o.ds could carry sun and moon across the sky? Who but G.o.ds could arrange the stars and command the phases of the moon? Perhaps, as many thought, the G.o.ds descended from heaven and took mortal form to visit their people. It would explain the mysterious strangers and their magic implements. And since heaven was surely a better place, it would explain why the mysterious strangers came so seldom.

Heaven, it turned out, was not in the sky.

Heaven was a tree, scarcely more than a shrub, ordinary in every way, pa.s.sed many times before, entirely familiar. On that day it exuded a scent of irresistible potency. Suddenly he had found himself p.r.o.ne at its roots, scratching with his bare hands at the rocky soil. The smell urged him forward, downward, indifferent to torn fingernails and flayed skin and the blood streaming from his hands. He must find- He did not know what.

Fingers digging madly found a gnarled, yellow-orange length of tree root. The scent grew overpowering. When next he was aware of himself, his stomach was painfully engorged. His jaws worked mindlessly on a mouthful of something almost too fibrous to chew. He was flat on his back beside a length of exposed tree root, from which a few rough-skinned tubers still clung. Sap oozed where more tubers had surely been ripped loose. In some dim recess of his thoughts, he knew it was a tuber like these on which he helplessly gnawed.

All around was a stench that part of him wanted to flee and part of him recognized was somehow himself himself. That his very scent could change was terrifying. Yet another part of him noted, with unusual clarity, that whatever had overcome him had left him helpless. This reek, if it repelled others as much as himself, was all that kept away his enemies.

The new smell was already fading, changing to yet another odor, something strangely right for him. How could that be? What more had changed? In a panic, he explored his body.

His hair had fallen out in clumps, from head and chest and limbs. His knees and elbows and hips protruded, magically become enormous. The knuckles of his hands were sore and enlarged. His mouth felt odd, the skin pulled unaccountably taut. When, fearfully, he explored with the hand unenc.u.mbered with a half-eaten tuber, his lips and gums were becoming one. His cheeks felt like cured animal hide. He patted his chest and legs and other arm. They, too, were becoming tough. He peered fearfully at his most personal parts-and they were gone!

He howled, his anguish m.u.f.fled by a mouthful of the root that had maimed him. And yet ...

Despite pain and shock and confusion, he could not help but notice: His thoughts had never been clearer.

He continued to chew.

THE DRONING OF MACHINERY CHANGED pitch as another deep ice core neared the surface.

Thssthfok returned from the eternal present of a breeder into this this present, awakening into a deep sense of loss. Breeders present, awakening into a deep sense of loss. Breeders felt felt. Then, he had been one with the land, one with his family, pa.s.sionate about every experience.

Intelligence was a pale subst.i.tute.

Only one emotion remained to him, all the more intense for subsuming the rest: He must must protect those left behind. Not his children-for they were long gone, whether dead or transformed like him by tree-of-life root-but protect those left behind. Not his children-for they were long gone, whether dead or transformed like him by tree-of-life root-but their their children's children's children, and their children besides. children's children's children, and their children besides.

As many generations must pa.s.s again before Thssthfok would return, while by ship time, coming and going at near light speed, hardly six years would have pa.s.sed. He himself would have aged even less, his biological processes slowed to near immobility in cold sleep.

Scent and memory were inextricably linked. With home fresh in Thssthfok's thoughts, the sterile, scentless air above this windswept ice oppressed him. Perhaps he would return for a while to the expedition's main base on the south-temperate continent, where the geologists and biologists labored. There he would find the scents of relatives, if only the weak emanations of other protectors. Shipboard, at least, there were synthesized scents. The best work of perfumers paled beside the heady, blended redolence of home and family, but it was something something.

A thunk thunk announced the arrival from deep below the surface of the latest ice sample. Working with tongs lest any detail be lost to the heat from his hands, Thssthfok put the slim cylinder into a clear, insulated bag. The layers had been automatically scanned, the results already displayed, but Thssthfok studied the ice for himself. When it came to winnowing pattern from noise, no machine could compete with eye and brain and eons of evolution. announced the arrival from deep below the surface of the latest ice sample. Working with tongs lest any detail be lost to the heat from his hands, Thssthfok put the slim cylinder into a clear, insulated bag. The layers had been automatically scanned, the results already displayed, but Thssthfok studied the ice for himself. When it came to winnowing pattern from noise, no machine could compete with eye and brain and eons of evolution.

Correcting effortlessly for the compression that varied with depth, Thssthfok pondered the strata in the ice. Some layers were thicker than others, the precipitation at this spot a clue to the extent of snowfall worldwide. At a glance he discerned cycles upon cycles upon cycles.

Sun and moon and neighboring planets, each in its own way, each at its own pace, tugged on this world. And so the shape of its...o...b..t changed, and the tilt of its axis, and the slow precession of its axial tilt. With each shift, the strength of sunlight varied across the globe.

Of such minutiae are climates made.

As had the samples before it, this latest core spoke of ice ages. Orbital variation explained most and volcanic ash layers the rest. The ice gave no reason to expect another ice age for many thousands of years.

Almost certainly, Pakhome would face an ice age sooner. If Thssthfok was lucky, that next ice age would arise from Pakhome's own astronomical cycles, long after his death. (If he was unlucky-well, with only normal luck-war would be what killed him. War killed most protectors. The compet.i.tion for resources was ever fierce.) A part of Thssthfok would find an ice age-especially one hastened by a nuclear winter-fascinating, but he was a protector more than climatologist. With his family at risk, too distant to defend, the prospect filled him with dread. Even a limited nuclear exchange would make the temperate zones uninhabitable for many years. Every family from those regions would set out to conquer new living s.p.a.ce for his breeders. The struggles for equatorial territory would be brutal.

Rilchuk, the island of Thssthfok's birth, the home of his family, straddled the equator. Their land would be prized. Breeders with the wrong scent-his family!-would be slaughtered by any conqueror.

Thssthfok thought: I must must find a New Rilchuk, whether on this planet or another, a place to shelter my descendants for many generations. find a New Rilchuk, whether on this planet or another, a place to shelter my descendants for many generations.

If I am not already too late.

As he had a hundred times since reawakening from cold sleep, Thssthfok suppressed that qualm. Let doubt once blossom and he would lose the will to live. It was better not to dwell on circ.u.mstances that could not be known.

He refocused on the ice core with renewed dedication. In his bones, he knew: This This is the world. The sooner he could prove it, the sooner he could bring his descendants from- is the world. The sooner he could prove it, the sooner he could bring his descendants from- Within a sealed vest pocket, Thssthfok's radio shrieked. It was tuned to the command channel, and the harsh warble was unambiguous: immediate emergency recall.

Recall? Thssthfok needed deeper cores to prove this world safe. To make his breeders safe. Even to wrap the ice cores properly and recover the drilling equipment would take half a day. He took out his radio. "Commander, request another day. The cores-"

Bphtolnok, commander of the mission, was stationed on their orbiting ramscoop. That the commander was Thssthfok's grandfather's sister would merit no favors. Everyone on the mission was family.

Bphtolnok cut off Thssthfok. "Aboard in two day-tenths, or be left behind."

2.

The recall of everyone from the planet brought chaos to the landing bay. Thssthfok was still securing his shuttle when he was again summoned.

He pressed through jammed corridors noisy with grumbling and the roar of ventilation fans. The full ship's complement was never meant to be awake onboard. Whatever had inspired the recall, these conditions could not persist. Life support could not sustain so many at once. Already, some must be queuing for the cold-sleep pods.

Even as Thssthfok struggled through the crowd, New Hope New Hope launched on full acceleration. launched on full acceleration.

He entered the commander's cabin to find, besides Bphtolnok, four people. Three, like the commander, were warriors, marked honorably with scars. The last, his half brother, Floshftok, was an astrophysicist.

Abandonment of a promising colony world. An emergency departure-and the commander away from the bridge. An urgent meeting that involved strategy, astrophysics, and climatology. Any of these circ.u.mstances was extraordinary. But all? There could be only one reason: Their breeders were at risk!

Any message from Rilchuk had been a hundred years on its way. Despite his first scent in days of family, Thssthfok knew despair. Protectors without breeders had no purpose. They lost the will to live, and their appet.i.te, and starved to death.

And yet.

Bphtolnok, at the least, knew what peril loomed-and she had acted decisively. There must yet be time. The danger must originate elsewhere than on Pakhome.

Floshftok's presence demonstrated an astrophysical dimension to the threat: something detected from afar. An unexpected neutrino flux, perhaps, from fusion reactors in a neighboring solar system. Or the hungry maw of a ramscoop approaching, or the white-hot exhaust of a fusion drive, ramscoop or otherwise, decelerating in this direction.

It was to distinguish remote threats from natural phenomena that an astrophysicist was part of the expedition.

Pak or alien, the response would be the same. If Pak, then certainly a rival for the pristine world New Hope New Hope had just deorbited. If alien, then at least potentially a rival. Thssthfok had no interest in another intelligent species. Curiosity was a breeder behavior, long outgrown. had just deorbited. If alien, then at least potentially a rival. Thssthfok had no interest in another intelligent species. Curiosity was a breeder behavior, long outgrown.

Pak or alien, intruders or neighbors, those whom Floshftok had seen must be destroyed.

All this flashed through Thssthfok's mind as he crossed the small cabin and took a seat. He leaned forward, desperate to know more.

"Recap," the commander ordered.

Floshftok evoked a holo display of the stellar neighborhood, expanses of false color washing past nearby stars. Each color denoted a type of radiation.

Thssthfok studied the image, too extensive to be other than an astronomical phenomenon. Lots of neutrinos and the radiant glow from ... what?

"Supernovae," Floshftok offered.

Plural. But how many? The wave front showed no curvature. Many supernovae then, the spherical wave fronts from each explosion averaging out. "The galactic core?" Thssthfok asked in wonderment. The closer an end-of-life star was to a supernova, the more likely- "A chain reaction," Floshftok agreed.

And so the meeting went, with seldom more than a word or a short phrase offered. The breeders for whose safety Thssthfok feared required many words to convey the simplest concept. Protectors wrung meaning from the subtlest clue, their minds racing faster than their reasoning could be put into words.

No supernovae shone in the night sky over New Rilchuk. What Floshftok had detected was the leading edge of the wave front. The radiant glow, in frequencies across the spectrum, must blaze from stellar remnants lagging behind the neutrinos. The shock wave would be coming on at one-tenth light speed, thousands of light-years thick, sterilizing every world in its path.

No wonder New Hope New Hope fled. fled.

Neither warrior nor climatologist nor astrophysicist could defeat exploding stars. He looked around the table. This time, one of the warriors beat Thssthfok to a conclusion.

Klssthfok, their most senior strategist, said, "The end of cycles."

FOR MILLIONS OF YEARS-how many, the historical record had too many gaps to ascertain-Pak had battled for their families and clans. Every possible advantage was embraced; every horrific consequence excused. In the process, Pak had visited upon themselves every imaginable disaster. Ecological failure. Gengineered plague. Nuclear winter. Bombardment from s.p.a.ce. Toxic deserts and radioactive wastelands. The legacy spanned Pakhome, the home system's asteroids and rocky moons, even the colonizable worlds of nearby stars.

The return from each collapse was harder, the recovery time longer. Petroleum and coal were long gone from Pakhome, as were most fissile materials. Deuterium and tritium had all but vanished from the seas. Metals were more often stripped from ancient ruins than found as ore in new mines. Only knowledge-sometimes-persisted to alleviate the suffering.

And to hasten the next next collapse. collapse.

Only there could be no recovery from a world sterilized.

"ONE FINAL COLLAPSE," Thssthfok said. This This was why he had been summoned. Once imminent disaster was recognized, every protector on Pakhome would have a common goal: escape with his breeders. was why he had been summoned. Once imminent disaster was recognized, every protector on Pakhome would have a common goal: escape with his breeders.

The resources did not exist to evacuate a world.

There would be war over the few starships, and any resources that might be used to build more. There would be war over every type of supply necessary to provision a ship. And because this was, inevitably, the final war, it would be fought without restraint.

However closely New Hope New Hope approached light speed, the ship could not approached light speed, the ship could not quite quite catch up to the wave front now rushing toward Pakhome to presage disaster. And yet, they must return for their breeders. They would arrive, inevitably, during the fiercest of all wars. catch up to the wave front now rushing toward Pakhome to presage disaster. And yet, they must return for their breeders. They would arrive, inevitably, during the fiercest of all wars.

No Pak living had seen a nuclear winter, and the strategists needed the best possible information about the conditions in which they would fight. While most crew slept through the coming flight, Thssthfok would be a.n.a.lyzing the conditions into which they would arrive.