There were twenty-four people in the band.

Most of the adults were dispersed over the landscape near the eroded sandstone bluff. They moved like slim shadows across the dusty ground, seeking out nuts and small game, silent, intent, expert. Mothers had taken their youngest children along, clamped to their backs or scuttling at their feet.

Far’s mother was working through a small stand of acacia trees that had been comprehensively destroyed by the passage of a herd of deinotheres. These ancient elephant types had used their downward-pointing tusks and stubby trunks to leave the trees broken and splintered, the ground churned up, and the roots hauled out. People weren’t the only foragers here: warthogs and bushpigs grunted and squealed as they pushed their ugly faces into the churned-up earth. The destruction was recent. Far could see giant beetles at work burying fresh deinothere dung, and aardvarks and honey badgers rooting in the ground, seeking the beetles’ larvae.

Such a place made for good foraging. A good strategy for finding food in an unfamiliar land was to seek out the leftovers of other animals, especially destructive types like elephants and pigs. In the smashed-up stand of trees, Far’s mother would find food that would have otherwise been hidden or inaccessible. Among the broken trunks there were even ready-made levers, struts, and digging sticks to prize out roots from the ground, broken branches to shake to get at fruit, and slivers of palm to dig out pith.

Far’s mother was a serene, elegant woman, tall even for her kind; she might have been called Calm. She walked with her two children, the sleeping baby cradled over one shoulder, and a son. The boy was half Far’s age but already nearly as tall as she was, a skinny youth Far thought of as the Brat: irritating, clever, and much too successful at competing for their mother’s attention and generosity.

Calm’s own mother, Far’s grandmother, was at her side. In her mid-forties now, the grandmother was too stiff to be of much help digging for food. But she assisted her daughter by keeping an eye on the youngest child. No human would have been surprised to see old people in this group; it would have looked very natural. But no previous types of primates had grown old; few had survived much past their fertile years. Why should their bodies continue to keep them alive when they could not contribute further to the gene pool? But now it was different; among Far’s kind, old people had a role.

Panting, dusty, Far climbed the rock. It was just an outcrop a hundred meters across bearing nothing but strands of tough grass and a few insects and lizards. But for the people it was a temporary home base, an island of comparative sanctuary in this open savannah, this sea of danger. On the outcrop itself a couple of men were repairing wooden spears. They worked absently, eyes roving, as if their hands were working by themselves. Some of the older children played, rehearsing for the adulthood to come. They wrestled, chased, mock-stalked each other. Two six-year-olds were engaged in clumsy foreplay, fingering each other’s nipples and bellies.

Far was neither an adult nor a child, and in this small band there was nobody close to her age. So she kept away from the rest and walked to the summit of the eroded sandstone lump. She found a bit of antelope jaw, deposited here by some scavenger, now scraped clean by hungry mouths and the patient work of insects. She cracked the bone into fragments on the rock, and used a sharp edge to scrape the sweat and dirt from her legs and belly.

From this vantage, the landscape was laid out, presenting a complex panorama. This was an immense valley. Huge geological anguish showed in a panorama of domes, lava flows, tiltings, and craters. To the east — and, beyond the horizon, in the west — the land had been uplifted, forming a plateau some three thousand meters high at its maximum, laden with fertile volcanic soil. The great plateau came to an end in a precipitate wall that plunged down into the valley.

This was the Rift Valley: a fracture between two separating tectonic plates. It ran for three thousand kilometers from the Red Sea and Ethiopia in the north down through Kenya, Uganda, Tanzania, and Malawi, terminating in Mozambique to the south. For twenty million years geological activity along the length of this great wound had created volcanoes, built highlands, and collapsed lowlands into valleys that channeled the waters into some of the continent’s largest lakes. The land itself had been remolded, laid down as layer upon layer of volcanic ash, interspersed with broad beds of shale and mudstone. On the volcanic hills grew humid forests, and a complex mosaic of vegetation, from woodland to savannah to scrub, filled the floor. It was a crowded, jumbled, varied place.

And it was full of animals.

As the sun continued to roll down the sky, so the creatures of the savannah became more active: the hippos wallowing in the marshes, the herds of stately elephant types washing serenely across the grasslands. There were many species of elephant, in fact, subtly differing in the shape of their backs, skulls, trunks. They trumpeted shrilly to each other, sailing like dusky ships through the sea of dust they kicked up. As well as these large herbivores there were many other species directly dependent on the grass: hares, porcupines, and cane rats, rooting pigs. Predators upon the grass eaters — and themselves prey for still more dangerous animals — included jackals, hyenas, and mongooses.

The animals of the savannah would have looked startlingly familiar to human eyes, for they had already become finely adapted to savannah conditions. But the richness and variety of the life here would have astounded an observer used to the Africa of human times. This was the richest region on Earth in terms of the number of mammalian species, their diversity and abundance, and this was one of its most prolific periods. In this crowded, complicated place, plains creatures like antelopes and elephants lived close to forest dwellers like pigs and bats. The Rift provided a rich, sprawling landscape that presented opportunities for adaptation for many species of animals, like elephants, pigs, antelopes — and people. This, indeed, was the crucible from which Far’s kind had emerged.

But they had not stayed here.

After Capo’s time, liberated from the last ancestral ties to the forest, Far’s people had become a wandering species. They had walked out of Africa: The first hominid footsteps had already been planted all along the southern coasts of the Asian landmass. Far’s grandmothers, though, had unwittingly completed a great circuit to north, east, and south, over many generations returning here, to the place their kind had originated.

Sitting on her outcrop, Far surveyed the landscape with a professional, calculating eye. In their wanderings, the people mostly followed water courses. They had come to this place from the north, and she could see the streambed they had followed, a silver snake that slashed through the grass and scrub. Along the riverbank the land was silty, watered, and dense with nutrients, and a vigorous mix of trees, thicket, and grassland grew there, marked by pillars of termite mounds. To the east the ground rose, becoming dry and barren, and to the west the forest grew thicker, making an impassable belt. But if she looked south she could see possibilities for tomorrow, a great corridor of savannah with the mixture of grass, scrub, and forest patches that her people preferred.

Far was still young, still learning about the world and how best to use it. But she had a deep, systematic understanding of her environment. She was already capable of assessing an unfamiliar landscape like this and picking out sources of food, water, and danger, even spying out routes for onward migration.