Forced to grow up too quickly, he had become introspective. He hid his thoughts behind a mass of beard that, year after year, became more dense and knotted, and his eyes seemed to recede beneath their great browridge of bone.

And, like his father, on each of his arms he bore long, ragged scars.

With a sigh Pebble returned to his own gloomy inspection of the nets and lures he had strung out in the deeper water. This pebbly beach was protected from the sea by an outstretched arm of land, and a freshwater stream trickled down over the beach from the base of the bluffs. The sea was the Mediterranean: This was Africa’s northern coast. Behind him, to the south, the land rose up in a series of bluffs. It was here that Pebble’s refugee people had at last made their home, on the dry grassy dunes above the high-water mark, in a hut constructed from driftwood and saplings.

As far as he knew Seal, playing with spiders and their webs, had come up with his own miniature way of fishing. But then, on this dismal shore, they had all been forced to learn fast about the use of the sea. In the early days there had been much splashing around as hunters used to chasing down antelope had hurled themselves through the shallows after darting fish and dolphins that evaded them easily. They had gone hungry, and despaired.

They had got the right idea, in the end, from watching the spiders, and the birds and small animals that occasionally got tangled up in bushes or canes with sticky foliage, or in thickets with trailing vines.

Gradually they had figured out the use of nets and traps and snares, woven from bark and bits of leather. Their first attempts had failed more often than not. But they had slowly developed skills in exploiting natural cords and vines, and learned how to weave, repair, and tie fibers. And it worked. If you were lucky you could trap fish, octopus, and turtles. The deeper into the water you went, the better the catch would be.

Well, it had had to work. Otherwise they would surely have starved.

Ironically the land to the south, beyond these coastal bluffs, was rich, a mosaic of woodland and grass and fresh- and saltwater pools. And there were plenty of animals, beyond the marshes and on the higher ground: red deer, horse, and rhinoceros, and many smaller herbivores. Sometimes the animals would even come down to the beaches in search of salt.

If the land had been empty of people it might have been a paradise for Pebble’s group. But the land was not empty, and that was the entire trouble.

On the horizon there was an island. His gaze was drawn there now. Though it was made misty blue by distance, even from here he could see how rich the island was, with lush vegetation running down every cleft of rock, almost to the ocean. And there were people there. He had seen them on clear days: skinny, tall people, who would run across their beaches and hilltops, pale flitting figures.

There he and his people would be safe, he thought. On an island like that, a scrap of land of their own, they could live forever, untroubled by strangers. If he could get there, perhaps he could fight those skinny folk for possession of their land.

If he could get there. But people could not swim like dolphins, and they could not walk over the water like insects. It was forever impossible.

So here they were, stuck.

They had never planned to come so far as this. None of them had planned any of this at all. They had just been forced to keep going, and going, while the years had worn away.

Pebble’s kind were by nature sedentary; these robust folk had long lost the wanderlust of Far’s day. It had stressed them hugely to be thrust into unfamiliar landscapes: For Pebble it was as if the great trek had been a long, slow breakdown, a time of madness and bewilderment.

During the journey the children had grown — Pebble himself had become a man — and their numbers had slowly risen, as more refugees from one disaster or another tagged along with them. And their numbers had grown in another way. Pebble had become a father; he had coupled with Green, the wistful woman who had come with them from the old settlement. But as they crossed a particularly harsh and dry land, the child had died.

And still they had found nowhere they could live. For the world was full of people.

Before the attack there had been twelve people in Pebble’s close extended family. They were self-sufficient, and very sedentary. They did not trade, never traveled much further than could be reached in a day’s walk.

But they had been aware of similar groups nearby, studded around the landscape, as immobile as trees.

In all there were over forty tribes in the larger clan of which Pebble’s people were part, around a thousand people. Sometimes there would be exchanges as youngsters from one “village” sought mates in another. And there was occasional conflict as two parties found themselves competing over a rich foraging ground or the target of a hunt. But such incidents were usually settled with nothing much more than a slanging match, some inconclusive wrestling, and in extreme cases a spear in the leg, a maiming which had evolved as a ritual punishment.

And every one of this thousand-strong band, from the smallest baby to the most wizened thirty-five-year-old crone, was marked with the characteristic red or black vertical stripes that Pebble still wore on his face.

Far would have been astonished to see what had become of her innocent innovation with the bits of ocher. What had started out as a half-unconscious sexual deception had become, over immense stretches of time, a kind of looser celebration of fecundity. Women and even some men would mark their legs with the characteristic color of fertility. Slowly, dim minds and fumbling fingers had experimented with other forms of markings, new symbols.

By now, though, this crude scribbling had a purpose. Pebble’s vertical markings were a kind of uniform, setting a boundary between his folk and others. You didn’t need to remember everybody in your group personally — as Capo had had to when he had tried to lead his followers. You didn’t need to know faces. All you needed was the symbol.

The symbols united the bands. In a way the symbols had become what they fought for. These crude stripes and body markings were the birth of art, but they were also the birth of nations, the birth of war. They would make possible conflicts that would transcend even the deaths of those who had started them. That was why hominid minds were becoming smarter at creating the symbols, with each new generation.

All across this landscape there were clans like this, clans of more or less the same size. They were all sedentary, all staying where they had been born, where their parents and grandparents had lived and died. Their languages were mutually incomprehensible. Indeed many of these communities were no longer even able to interbreed, so long had they been isolated. And there they stayed, until they were displaced by some natural catastrophe like a climate shift or a flood — or by other people.

Which was why the clans had formed in the first place, of course: to keep out the refugees.

It had been terribly hard for them. At last, after eleven years, they had come to this place, this beach, and they had been forced to stop, for here the land had run out.

Now Pebble heard a mournful cry from up the beach. “Hey, hey! Help, help!”

Pebble stood and peered that way. He saw two stocky figures staggering toward the hut. They were Hands and Hyena, the one characterized by his huge, powerful hands, the other by his habit, when hunting, of laughing like a scavenger. These two men had joined Pebble’s group during their long odyssey. But now they were struggling. Hyena was leaning heavily on the powerful shoulders of his companion, and even from here Pebble could hear Hyena’s wheezing gasps.