Sir Arthur C. Clarke is a living legend, a writer whose name has been synonymous with science fiction for more than fifty years. An indomitable believer in human and scientific potential, Clarke is a genuine visionary. If Clarke has an heir among today's science fiction writers, it is award-winning author Stephen Baxter. In each of his acclaimed novels, Baxter has demonstrated dazzling gifts of imagination and intellect, along with a rare ability to bring the most cerebral science dramatically to life. Now these two champions of humanism and scientific speculation have combined their talents in a novel sure to be one of the most talked-about of the year, a "2001 for the new millennium. TIME'S EYEFor eons, Earth has been under observation by the Firstborn, beings almost as old as the universe itself. The Firstborn are unknown to humankind-- until they act. In an instant, Earth is carved up and reassembled like a huge jigsaw puzzle. Suddenly the planet and every living thing on it no longer exist in a single timeline. Instead, the world becomes a patchwork of eras, from prehistory to 2037, each with its own indigenous inhabitants.Scattered across the planet are floating silver orbs impervious to all weapons and impossible to communicate with. Are these technologically advanced devices responsible for creating and sustaining the rifts in time? Are they cameras through which inscrutable alien eyes are watching? Or are they something stranger and more terrifying still?The answer may lie in the ancient city of Babylon, where two groups of refugees from 2037--three cosmonauts returning to Earth from the International Space Station, and three United Nations peacekeepers on a mission inAfghanistan--have detected radio signals: the only such signals on the planet, apart from their own. The peacekeepers find allies in nineteenth-century British troops and in the armies of Alexander the Great. The astronauts, crash-landed in the steppes of Asia, join forces with the Mongol horde led by Genghis Khan. The two sides set out for Babylon, each determined to win the race for knowledge . . . and the power that lies within.Yet the real power is beyond human control, perhaps even human understanding. As two great armies face off before the gates of Babylon, it watches, waiting. . . .

"From the Hardcover edition.

Arthur C. Clarke is considered the greatest science fiction writer of all time and is an international treasure in many other ways, including the fact that an article by him in 1945 led to the invention of satellite technology. Books by Clarke—both fiction and nonfiction—have sold more than one hundred million copies in print worldwide. He lives in Sri Lanka.

Stephen Baxter is a trained engineer with degrees from Cambridge and Southampton Universities. Baxter is the acclaimed author of the Manifold novels and Evolution. He is the winner of the British Science Fiction Award, the Locus Award, the John W. Campbell Award, and the Philip K. Dick Award, as well as being a nominee for an Arthur C. Clarke Award.

Chapter 1

Part 1

Discontinuity

1: Seeker

For thirty million years the planet had cooled and dried, until, in the north, ice sheets gouged at the continents. The belt of forest that had once stretched across Africa and Eurasia, nearly continuous from the Atlantic coast to the Far East, had broken into dwindling pockets. The creatures who had once inhabited that timeless green had been forced to adapt, or move.

Seeker's kind had done both.

Her infant clinging to her chest, Seeker crouched in the shadows at the fringe of the scrap of forest. Her deep eyes, under their bony hood of brow, peered out into brightness. The land beyond the forest was a plain, drenched in light and heat. It was a place of terrible simplicity, where death came swiftly. But it was a place of opportunity. This place would one day be the border country between Pakistan and Afghanistan, called by some the North-West Frontier.

Today, not far from the ragged fringe of the forest, an antelope carcass lay on the ground. The animal was not long dead-its wounds still oozed sticky blood-but the lions had already eaten their fill, and the other scavengers of the plain, the hyenas and the birds, had yet to discover it.

Seeker stood upright, unfolding her long legs, and peered around.

Seeker was an ape. Her body, thickly covered with dense black hair, was little more than a meter tall. Carrying little fat, her skin was slack. Her face was pulled forward into a muzzle, and her limbs were relics of an arboreal past: she had long arms, short legs. She looked very like a chimpanzee, in fact, but the split of her kind from those cousins of the deeper forest already lay some three million years in the past. Seeker stood comfortably upright, a true biped, her hips and pelvis more human than any chimp's.

Seeker's kind were scavengers, and not particularly effective ones. But they had advantages that no other animal in the world possessed. Cocooned in the unchanging forest, no chimp would ever make a tool as complex as the crude but laboriously crafted axe Seeker held in her fingers. And there was something in her eyes, a spark, beyond any other ape.

There was no sign of immediate danger. She stepped boldly out into the sun, her child clinging to her chest. One by one, timidly, walking upright or knuckle-walking, the rest of the troop followed her.

The infant squealed and pinched her mother's fur painfully. Seeker's kind had no names-these creatures' language was still little more sophisticated than the songs of birds-but since she had been born, this baby, Seeker's second, had been ferociously strong in the way she clung onto her mother, and Seeker thought of her as something like "Grasper."

Burdened by the child, Seeker was among the last of the troop to reach the fallen antelope, and the others were already hacking with their chipped stones at the cartilage and skin that connected the animal's limbs to its body. This butchery was a way to get a fast return of meat; the limbs could be hauled quickly back to the relative safety of the forest, and consumed at leisure. Seeker joined in the work with a will. The harsh sunlight was uncomfortable, though. It would be another million years before Seeker's remote descendants, much more human in form, could stay out in the light, in bodies able to sweat and store moisture in fatty reserves, bodies like spacesuits built to survive the savannah.

The shrinking of the world forest had been a catastrophe for the apes that had once inhabited it. Already the evolutionary zenith of this great family of animals lay deep in the past. But some had adapted. Seeker's kind still needed the forest's shade, still crept into treetop nests each night, but by day they would dart out into the open to exploit easy scavenging opportunities like this. It was a hazardous way to make a living, but it was better than starving. As the forest fragmented further, more edge became available, and the living space for fringe-dwellers actually expanded. And as they scuttled perilously between two worlds, the blind scalpels of variation and selection shaped these desperate apes.

Now there was a concerted yapping, a patter of swift paws on the ground. Hyenas had belatedly scented the blood of the antelope, and were approaching in a great cloud of dust.

The upright apes had hacked off only three of the antelope's limbs. But there was no more time. Clutching her child to her chest, Seeker raced after her troop toward the cool ancestral dark of the forest.

That night, as Seeker lay in her treetop nest of folded branches, something woke her. Grasper, curled up beside her mother, snored softly.

There was something in the air, a faint scent in her nostrils, that tasted of change.

Seeker was an animal fully dependent on the ecology in which she was embedded, and she was very sensitive to change. But there was more than an animal's sensibility in her: as she peered at the stars with eyes still adapted for narrow forest spaces, she felt an inchoate curiosity.

If she had needed a name, it might have been Seeker.

It was that spark of curiosity, a kind of dim ancestor of wanderlust, that had guided her kind so far out of Africa. As the Ice Ages bit, the remnant forest pockets dwindled further or vanished. To survive, the forest-fringe apes would rush across the hazard of the open plain to a new forest clump, the imagined safety of a new home. Even those who survived would rarely make more than one such journey in a lifetime, a single odyssey of a kilometer or so. But some did survive, and flourish; and some of their children passed on farther.

In this way, as thousands of generations ticked by, the forest-fringe apes had slowly diffused out of Africa, reaching as far as Central Asia, and crossing the Gibraltar land bridge into Spain. It was a forward echo of more purposeful migrations in the future. But the apes were always sparse, and left few traces; no human paleontologist would ever suspect they had come so far out of Africa as this place, northwest India, or that they had gone farther still.

And now, as Seeker peered up at the sky, a single star slid across her field of view, slow, steady, purposeful as a cat. It was bright enough to cast a shadow, she saw. Wonder and fear warred in her. She raised a hand, but the sliding star was beyond the reach of her fingers.

This far into the night, India was deep in the shadow of Earth. But where the surface of the turning planet was bathed in sunlight, there was a shimmering-rippling color, brown and blue and green, flickering in patches like tiny doors opening. The tide of subtle changes washed around the planet like a second terminator.

The world shivered around Seeker, and she clutched her child close.

In the morning, the troop was agitated. The air was cooler today, somehow sharper, and laden with a tang a human might have called electric. The light was strange, bright and washed-out. Even here, in the depths of the forest, a breeze stirred, rustling the leaves of the trees. Something was different, something had changed, and the animals were disturbed.

Boldly Seeker walked into the breeze. Grasper, chattering, knuckle-walked after her.

Seeker reached the edge of the forest. On a plain already bright with morning, nothing stirred. Seeker peered around, a faint spark of puzzlement lodging in her mind. Her forest-adapted mind was poor at analyzing landscapes, but it seemed to her that the land was different. Surely there had been more green yesterday; surely there had been forest scraps in the lee of those worn hills, and surely water had run along that arid gully. But it was difficult to be sure. Her memories, always incoherent, were already fading.

But there was an object in the sky.

It was not a bird, for it did not move or fly, and not a cloud, for it was hard and definite and round. And it shone, almost as bright as the sun itself.

Drawn, she walked out of the forest's shadows and into the open.

She walked back and forth, underneath the thing, inspecting it. It was about the size of her head, and it swam with light-or rather the light of the sun rippled from it, as it would flash from the surface of a stream. It had no smell. It was like a piece of fruit, hanging from a branch, and yet there was no tree. Four billion years of adaptation to Earth's unvarying gravity field had instilled in her the instinct that nothing so small and hard could hover unsupported in the air: this was something new, and therefore to be feared. But it did not fall on her or attack her in any way.

She craned up on tiptoes, peering at the sphere. She saw two eyes gazing back at her.

She grunted and dropped to the ground. But the floating sphere did not react, and when she looked up again she understood. The sphere was returning her reflection, though twisted and distorted; the eyes had been her own, just as she had seen them before in the smooth surface of still water. Of all Earth's animals only her kind could have recognized herself in such a reflection, for only her kind had any true sense of self. But it seemed to her, dimly, that by holding such an image the floating sphere was looking at her just as she looked at it, as if it was a vast Eye itself.

She reached up, but even on tiptoe, with her long tree-climbers' arms extended, she could not reach it. With more time, it might have occurred to her to find something to stand on to reach the sphere, a rock or a heap of branches.

But Grasper screamed.

Seeker fell to all fours and was knuckle-running before she had even realized it. When she saw what was happening to her child she was terrified.

Two creatures stood over Grasper. They were like apes, but they were upright and tall. They had bright red torsos, as if their bodies were soaked in blood, and their faces were flat and hairless. And they had Grasper. They had dropped something, like lianas or vines, over the infant. Grasper struggled, yelled and bit, but the two tall creatures easily held down the lianas to trap her.

Seeker leapt, screaming, her teeth bared.

One of the red-breasted creatures saw her. His eyes widened with shock. He brought around a stick, and whirled it through the air. Something impossibly hard slammed against the side of her head. Seeker was heavy and fast enough that her momentum brought her crashing into the creature, knocking him to the ground. But her head was full of stars, her mouth full of the taste of blood.

To the east a blanket of black, boiling cloud erupted out of the horizon. There was a remote rumble of thunder, and lightning flared.



2: Little Bird



At the moment of Discontinuity, Bisesa Dutt was in the air.

From her position in the back of the helicopter cockpit, Bisesa's visibility was limited-which was ironic, since the whole point of the mission was her observation of the ground. But as the Little Bird rose, and her view opened up, she could see the base's neat rows of prefabricated hangars, all lined up with the spurious regularity of the military mind. This UN base had been here for three decades already, and these "temporary" structures had acquired a certain shabby grandeur, and the dirt roads that led away across the plain were hard-packed.

As the Bird swooped higher, the base blurred to a smear of whitewash and camouflage canvas, lost in the huge palm of the land. The ground was desolate, with here and there a splash of gray-green where a stand of trees or scrubby grass struggled for life. But in the distance mountains shouldered over the horizon, white-topped, magnificent.

The Bird lurched sideways, and Bisesa was thrown against the curving wall.

Casey Othic, the prime pilot, hauled on his stick, and soon the flight leveled out again, with the Bird swooping a little lower over the rock-strewn ground. He turned and grinned at Bisesa. "Sorry about that. Gusts like that sure weren't in the forecasts. But what do those double domes know? You okay back there?"

His voice was overloud in Bisesa's headset. "I feel like I'm on the back shelf of a Corvette."

His grin widened, showing perfect teeth. "No need to shout. I can hear you on the radio." He tapped his helmet. "Ra-di-o. You have those in the Brit army yet?"

In the seat beside Casey, Abdikadir Omar, the backup pilot, glanced at the American, shaking his head disapprovingly.

The Little Bird was a bubble-front observation chopper. It was derived from an attack helicopter that had been flying since the end of the twentieth century. In this calmer year of 2037, this Bird was dedicated to more peaceful tasks: observation, search and rescue. Its bubble cockpit had been expanded to take a crew of three, the two pilots up front and Bisesa crammed on her bench in the back.

Casey flew his veteran machine casually, one-handed. Casey Othic's rank was chief warrant officer, and he had been seconded from the US Air and Space Force to this UN detachment. He was a squat, bulky man. His helmet was UN sky blue, but he had adorned it with a strictly nonregulation Stars and Stripes, an animated flag rippling in a simulated breeze. His HUD, head-up display, was a thick visor that covered most of his face above the nose, black to Bisesa's view, so that she could only see his broad, chomping jaw.

"I can tell you're checking me out, despite that stupid visor," Bisesa said laconically.

Abdikadir, a handsome Pashtun, glanced back and grinned. "Spend enough time around apes like Casey and you'll get used to it."

Casey said, "I'm the perfect gentleman." He leaned a bit so he could see her name tag. "Bisesa Dutt. What's that, a Pakistani name?"

"Indian."

"So you're from India? But your accent is-what, Australian?"

She suppressed a sigh; Americans never recognized regional accents. "I'm a Mancunian. From Manchester, England. I'm British-third generation."

Casey started to talk like Cary Grant. "Welcome aboard, Lady Dutt."

Abdikadir punched Casey's arm. "Man, you're such a cliché, you just go from one stereotype to another. Bisesa, this is your first mission?"

"Second," said Bisesa.

"I've flown with this asshole a dozen times and he's always the same, whoever's in the back. Don't let him bug you."

"He doesn't," she said equably. "He's just bored."

Casey laughed coarsely. "It is kind of dull here at Clavius Base. But you ought to be at home, Lady Dutt, out here on the North-West Frontier. We'll have to see if we can find you some fuzzy-wuzzies to pick off with your elephant gun."

Abdikadir grinned at Bisesa. "What can you expect from a jock Christian?"