Evolution

The geological infrastructure of the Rift Valley — the plateau, the rocks, the volcanic mountains, the great sweep of the valley itself — had been left largely unchanged by time. But since Far’s time this had become a sparse, dry place. Scattered stands of acacia, leadwood, and wild laurel had replaced the denser thickets and forest pockets of the past. Even the grasslands were subtly different, great swaths of them dominated by a handful of fire-resistant species. Meanwhile, the great animal communities of the past had imploded. There was not an elephant to be seen across this great dust bowl, not an antelope or giraffe. It was as if life had crashed here. The place was depleted. Far would have been startled by its impoverishment.

But the Brat’s wretched remains had left their mark on the world: a scrap of moisture trapped in that buried, upturned skullcap had been enough to help establish the yam.

Incuriously Pebble closed his fist. The little skull was crushed to thin shards, and he let the dust fall back into the hole. He reached for his digging tool; there was still some root to be dug out.

That was when he glimpsed the strangers.

He crouched down behind a bluff, holding his breath.

They were hunters; he could see that immediately. They were following an old elephant track. Elephants walked to water, and where there was water, there would be many animals, including the medium-sized creatures like deer that people hunted by preference.

There were four of them, three men and a woman, all adults. As they walked the hunters’ legs swung powerfully, with their torsos tipped a little forward. It was a gait built for strength, not elegance or speed: the hunters had none of the fleetness of Far. Thick beards hid the men’s dark faces, and the woman had tied her long hair back with a bit of leather. Unlike Pebble this group wore clothes: just bits of hide, unsewn and tied around the body with strips of leather or plaited bark. Pebble could see the bite marks in the clothes. Leather was treated by chewing and stretching it with the teeth, and a major function of that big ridge of bone on Pebble’s brow was to provide an anchor for the jaws that must do such mighty work.

And they carried weapons: narrow wooden throwing spears, and shorter, stubby thrusting spears, great logs of hardwood with slabs of stone stuck to the end with blobs of resin and leather ties. They were giants’ weapons that a human would have had trouble lifting, let alone wielding in anger.

They were robust folk, people like Pebble’s kind. But Pebble could see ocher markings scrawled on the skin of their faces, hands, and arms. Where Pebble’s own adornment was made up of vertical lines — bars and stripes and bands, all pointing to the sky — these people wore a kind of clumsy Crosshatch, sketched by thick fingers.

They were strangers. You could tell that by the markings. And strangers meant trouble. That was a law that worked as invariably as the rising of the sun, the waxing of the Moon.

Pebble waited until the newcomers had passed out of sight behind a stand of sparse acacia. Then, as silently as his slablike body would allow him, he began to run for home. The yam tubers he had dug up lay abandoned on the ground behind him — with his digging stick.

Pebble’s home was a kind of village, with four large huts set roughly around a clearing. And yet it was not a village, for his people lived not quite as any humans ever would.

Pebble stood, panting, in the central clearing. Nobody was around. Close to the door of one hut a fire smoldered. The trampled ground was scattered with bone, vegetable debris, tools, mattresses of leaves and grass, trays of bark, pegs, wedges, a broken spear, discarded bits of leather. The place was a mess.

The huts were crude and ugly, but serviceable. They had been built of thick saplings set in rough circles in holes in the ground. The gaps between the saplings were filled with rattan cane split into switches, and overlapping leaves, bunches of rushes, bark. The saplings were bent over together and their ends pushed over and under each other. It was a kind of weaving that Capo would have recognized, for five million years earlier he had made his treetop nests in much the same way: Every innovation of necessity was built on what had gone before.

The huts were old. The people had lived here for generations. The dirt beneath Pebble’s feet was thick with the bones of his ancestors. The people felt safe here. This was their place, their land.

But now, Pebble knew, all that might change.

He raised his head to the washed-out sky. "U-lu-lu-lu-lu! U-lu-lu-lu-lu!…" It was a cry of danger, of pain, the first cry any child learned after the feed-me yell.