She could just walk off into the dust, alone.

Why live in a world without Silent?

But in the end she came out of the worst of her darkness.

Once again she started to gather food, eat, and drink. She had to: If she had not, she would have died. This was not a rich society. Though care was taken of the weak, the injured, and the elderly, there was little energy to spare for those who would not help themselves.

She had always been a skillful hunter and sharp-eyed forager. With the tools she invented, modified, or improvised, she was actually more effective than some of those younger and stronger than she was. She recovered rapidly. But the confusion in her head didn't dissipate.

She wasn't sure what first gave her the impulse to make the markings in the rock.

It wasn't even conscious. She was sitting beside an outcropping of soft, buttery sandstone, with a basalt scraper in her hand; she had been preparing a goat hide. And there, incised neatly into the rock, was a pair of zigzag lines, running crisply parallel to each other.

At first the marks puzzled her. But then she saw a scattering of sand grains under the scraping. She understood, the causal connections linking up as they always did. Without thinking, she she had used the scraper; the scraper had made the markings. So had used the scraper; the scraper had made the markings. So she she had made the markings. had made the markings.

What sparked her interest was that they were like the lines in her head.

Dropping the bit of leather she had been working, she knelt before the rock. She felt peculiarly excited. She turned the blunted scraper over to expose a fresh edge and dug it into the rock, tracing a line. She managed a neat spiral, circling to nothing at its center. It wasn't as clean and bright as the shapes in her head; it was clumsily scratched, the depth of line uneven, the curve angular and awkward.

So she tried again. She had always had a delicate skill when crafting tools from stone or wood or bone. This time the spiral was a little smoother, a little closer to the ideal inside her eyes. So she did it again. And again and again, until the unprepossessing lump of rock was covered in spirals, loops, whorls, and tracks.

It really was just like what she saw when she closed her eyes. It seemed miraculous to find that she was able to make the same shapes outside her head as she saw inside.

Later it occurred to her to try ocher.

People still used the red iron ore as a crayon to mark their skin with tribal scribbles, just as they had in Pebble's day. Now Mother experimented with the soft stuff, and found it much easier to use on rock than a scraper. And it could be applied to other surfaces as well. Soon her arms and legs- and the bits of skin she wore or draped over her shelter, and her tools and scrapers of stone and bone and wood- were all covered with loops and whorls and zigzags.

It was the flower that sparked the next stage of her peculiar development.

It was a kind of sunflower: not spectacular, its seeds neither edible nor poisonous, of no great interest. But its petals surrounded a neat spiral of yellow, twisting down toward a black central heart. She fell on the flower with a cry of recognition.

After that she started to see her shapes everywhere: the spirals of shells and cones, the lattices of honeycombs, even the spectacular zigzags of lightning that arced from the sky during storms. It was as if the contents of her dark skull were mapping themselves on to the world outside.

It was a girl who was the first to emulate her.

Mother saw her walking past, a rabbit over her shoulder- and a crimson spiral on her cheek, coiled under her eye. Next it was Sapling, with wavy lines on his long arms.

After that she started to see the lines and loops appearing everywhere, like a rash spreading over the surfaces of the encampment and the people's bodies. If she came up with some new design, a lattice or a nest of curves, it would quickly be copied and even elaborated on- especially by the young.

It was oddly satisfying. People were not avoiding her now. They were copying copying her. She became a kind of leader, in a way she never had been before. her. She became a kind of leader, in a way she never had been before.

But Sour was less pleased with Mother's new status. She kept her distance from Mother. In fact the two women had scarcely acknowledged each other's existence since the death of the boy.

Still, none of the designs, drawn by herself or others, came close to the glowing geometric perfection that came drifting silently through her head. It got to the point when she almost wished for the pain to return, so she could see them again.

At times, the changes in her consciousness scared her. What did this mean mean? She instinctively sought connections; that was her nature. But what connection could there be between a flash of light in her eyes and a towering storm in the sky? Did the storm cause the light in her head- or the other way around?

Life continued, the endless cycles of drawing breath, gathering food, the arcing of sun and Moon, the body's slow aging. And as the months wore by Mother sank deeper into the strangeness of her sensorium. She was beginning to see connections everywhere everywhere. It was as if the world were crisscrossed by causes like the threads of a vast, invisible spider's web. She felt as if she were dissolving, her sense of self dissipating.

But in all her inward wandering she clung to the memory of her son, a memory that was like an unending ache, like the stump of an amputated limb.

And gradually Silent's death began to seem to her the focus of all those causal tracks.

A wordless consensus was reached that the encampment should be broken up. The people prepared to move on.

Mother came with them. Sapling and others showed relief. Some had thought she might insist on staying beside the hole in the ground that contained the bones of her son.

After a long trek they reached a new camp, close to a mud-rimmed lake. They set up their hides and made their pallets. But as the dryness continued, life remained hard, and the children and old ones suffered.

One day Sapling brought Mother the head of a young ostrich. Its neck had been severed a hand's length below the jaw, and the head neatly punctured by a spear.

To bring down a fleet ostrich- to aim for the tiny head of a running bird, from fifty or seventy meters, and to bring it down- was a feat indeed. After months of practice Sapling and the other young hunters had learned to use the spear-thrower to hurl their weapons across unprecedented distances and with stunning accuracy. Mother's invention was a powerful one. With growing confidence the hunters had begun to penetrate further into the savannah, and soon the prey animals of the plains would learn to fear them greatly. It was as if the hunters had suddenly been given guns.

Today Sapling seemed bursting with the memory of his kill. Before the woman who had first showed him how to use the spear-thrower, he mimed how he had hurled the spear, how it had flexed and leapt, how it had flown to its precise target. "Bird fast, fast," he said, his feet paddling the ground. "Run fast." He pointed to himself. "I, I. Hide. Rock. Bird fast, fast. Spear..." He leapt out from behind his invisible rock and mimed hurling his triumphant spear once more.

Mother had little time for people these days. She was becoming increasingly absorbed in her own new perceptions. But she tolerated Sapling, who was the nearest thing to a friend she had. Absently she listened to his babbling.

"Wind carry smell. Smell touch ostrich. Ostrich run. Now, here. Stand, stand, hide. Wind carry smell. Ostrich here, wind there, wind carry smell away away..."

His language was something like a pidgin. The words were simple, just nouns, verbs, adjectives with no inflectional endings. There was still much use of repetition and mime for emphasis. And with little real structure, there was a linguistic free-for-all: It didn't help communication that no two people, even brought up as siblings, ever talked quite alike.

But still, Sapling now occasionally used sentences. He had picked up the habit from Mother. Each sentence was a genuine subject-verb-object compound. The people's protolanguage was quickly developing around this seed of structure. Already the chattering people had had to invent pronouns- you, me, him, her you, me, him, her- and different ways of expressing actions and their outcomes: I did kill, I am killing, I did not kill I did kill, I am killing, I did not kill... They were able to express comparatives and negatives, explore alternatives. They could consider going to the lake today, or not going to the lake, all in a universe of words, where before they would have had to pick one path or another, or split into factions.

It wasn't yet a full language. It wasn't even as rich as a creole. But it was a start, and it was growing fast.

And in a sense Mother had discovered, not invented, that basic sentence structure. Its central logic reflected hominids' deep apprehension of the world- a world of objects with properties- which reflected in turn a still deeper neural architecture common to most mammals. If a lion could have spoken, or an elephant, it would have spoken this way too. This central underpinning would be shared by almost all the myriad human languages that would follow in the ages to come, a universal template reflecting the essential causality of the world and the human perception of it. But it had taken Mother's dark genius to give that deep architecture expression, and to inspire the linguistic superstructure that rapidly followed.

And now it was time for another step.

Sapling said something that grabbed her attention. "Spear kill bird," he said excitedly. "Spear kill bird, spear kill bird..."

She frowned. "No, no."

He stopped in midflow. Wrapped up in his performance he seemed to have forgotten she was there. "Spear kill bird." He mimed the spear's flight. He even picked up the ostrich's ragged head and arced his outstretched hand toward it just as his spear had flown, straight and true.

"No!" she barked. She got up and grabbed his hand. "You lift hand." She slapped the spear-thrower into his grip. "Hand push stick. Stick push spear. Spear kill bird." lift hand." She slapped the spear-thrower into his grip. "Hand push stick. Stick push spear. Spear kill bird."

He pulled back, baffled. "Spear kill bird." Isn't that what I said? Isn't that what I said?

Irritated, she went through it again. "You lift hand. Spear kill bird. You You kill bird." There was a causal chain, but the kill bird." There was a causal chain, but the intention intention resided only in one place; in Sapling's head. She could see it clearly. resided only in one place; in Sapling's head. She could see it clearly. He He had killed the bird, not the spear. She slapped his head. had killed the bird, not the spear. She slapped his head. This is where the bird died, dummy. Inside your mind. The rest is detail. This is where the bird died, dummy. Inside your mind. The rest is detail. They argued for a while, but Sapling grew increasingly confused, his simple boyish pleasure in his kill waning now that his boasting had degenerated into this peculiar philosophical discussion. They argued for a while, but Sapling grew increasingly confused, his simple boyish pleasure in his kill waning now that his boasting had degenerated into this peculiar philosophical discussion.

Then a bolt of pain stabbed through Mother's temples, as sharply and suddenly as Sapling's spear of hardened wood must have slammed through the head of that hapless ostrich. She stumbled to her knees, her fists pressed to her temples.

But now, suddenly, in that instant of pain, she could see a new truth.

She imagined the spear arcing through the air, like the bright lightning in her head, piercing the bird's skull and extinguishing its life. She She knew that Sapling had thrown the spear. He had willed the bird dead, and everything else that followed was irrelevant. knew that Sapling had thrown the spear. He had willed the bird dead, and everything else that followed was irrelevant.

But what if she hadn't hadn't seen Sapling throw the spear? What if he had been hidden by a rock, a tree? Would she have believed that the spear was the ultimate cause- that the spear itself had intended to kill the bird? No, of course not. Even if she couldn't see the whole causal chain, it must exist. If she saw the spear fly, she would seen Sapling throw the spear? What if he had been hidden by a rock, a tree? Would she have believed that the spear was the ultimate cause- that the spear itself had intended to kill the bird? No, of course not. Even if she couldn't see the whole causal chain, it must exist. If she saw the spear fly, she would know know somebody must have thrown it. somebody must have thrown it.

Her peculiar vision of the world, the spiderweb of causes stretching across the world and from past to future, deepened further. If an ostrich fell, a hunter had willed it. And if a person died, another was to blame. As simple as that. She saw all this immediately, understood it on a deep intuitive level below words, as new connections opened in her complex, fast-developing consciousness.

The logic was clear, compelling. Appalling. Comforting.

And she knew how she had to act on this new insight.

She became aware that Sapling was kneeling before her, holding her shoulders. "Hurt? Head? Water. Sleep. Here..." He took her arm, trying to help her stand.

But that flash of pain had come and gone in an instant, a meteor leaving a trail of shattered and remade connections in her mind. She stood up and pushed past him, stalking back toward the settlement. There was only one person she needed now, one thing she had to do.

Sour was in her shelter, a rough lean-to of palm fronds, sleeping off the heat of the day.

Mother stood over her. In her arms she held a massive boulder, the largest she could carry; she cradled it as once she had cradled Silent.

Mother had never forgotten the day when Silent had first fallen ill. On that day everything had changed for her, as if the land had pivoted around her, as if the clouds and rocks had exchanged places. It had been the start of the pain. And she hadn't forgotten Sour's half smile. If I can't have a kid of my own, If I can't have a kid of my own, she had been saying, she had been saying, I'm glad you will lose yours. I'm glad you will lose yours.

Now she saw everything clearly. Silent's death had not been random. Nothing happened by chance in Mother's universe: not anymore. Everything was connected; everything had meaning. She was the first conspiracy theorist.

And the first person she indicted was her closest surviving family member.

Mother didn't know how how Sour had committed her crime. It might have been a look, a word, a touch- some subtle way, an invisible weapon that had brought the boy down as surely as a spear of carved wood- but Sour had committed her crime. It might have been a look, a word, a touch- some subtle way, an invisible weapon that had brought the boy down as surely as a spear of carved wood- but how how didn't matter. All that mattered was that Mother now knew who to blame. didn't matter. All that mattered was that Mother now knew who to blame.

She raised the rock.

In her last moment Sour woke, disturbed by Mother's movement. And she saw the rock falling toward her head. Her world ended, as thoroughly and suddenly extinguished as Cretaceous Earth's by the Devil's Tail.

The hominid brain, fueled by the need for increasing smartness, fed by the people's new fat-rich diet, had grown rapidly. It was more complex than any computer that humans would ever build. Inside Mother's head were a hundred billion neurons- interacting biochemical switches- a number comparable to the number of stars in the Galaxy. But each of those switches was capable of taking a hundred thousand variable positions. And this whole suite of complexity was bathed in a fluid laced with more than a thousand chemicals that varied with time, season, stress, diet, age, and a hundred other influences, each of which could affect the functioning of the switches.

Before Mother, people's minds were compartmented, with their subtle consciousness restricted to their social dealings while specialized modules dealt with such functions as toolmaking and environmental understanding, as well as more basic physiological functions such as breathing. The various functions of the brain had developed to some degree in isolation from one another, like separate subroutines not united into a master program.

It was all very jury-rigged, though. And this hugely complex biochemical computer was prone to mutation.

The physical difference between Mother's brain and those of the people around her was tiny, the result of a minor mutation, a small change in the chemistry of the fat in her skull, a slight rewiring of the neuronal circuitry that underpinned her consciousness. But that was enough to give her a new flexibility of thinking, a breaking-through between the different compartments of her intelligence- and a hugely different perception.

But the rewiring of so immensely complicated an organic computer inevitably had side effects- not all of them desirable.

It wasn't just the migraine. Mother was suffering from what might have been diagnosed as a kind of schizophrenia. Her symptoms had been triggered by the death of her son. Even in this first flowering of human creativity, Mother foreshadowed many of the flawed geniuses who would illuminate, and darken, human history in the generations that lay in the future.

There was no police force here. But random killers were not welcome in such a small, close-knit community. So they came to seek her out.

But she had gone.

Alone, she walked for days across the savannah, back to the place they had last camped, the place of the dry gorge. The patch of ground was now so weathered and overgrown that surely only she could have recognized it.

She cleared away the vegetation, grass, and scrub. Then she took a digging-stick and, like long-dead Pebble digging for yams, she began to beat her way into the earth.

At last, a meter or so deep, she glimpsed the white of bone. The first fragment she retrieved was a rib. In the harsh sunlight it gleamed white, utterly cleansed of flesh and blood; she was struck by the awful efficiency of the worms. But it wasn't ribs she wanted. She dropped the bone and dug her hands into the soil. She knew where to look, remembered every detail of that terrible day when Silent had been flung into this bit of ground, how he had fallen with head lolling back and limbs splayed, the stains of his death shit still showing on his thin legs.

Soon she closed her hands on his head.

She lifted the skull into the air, the gaping eyes facing her. A scrap of cartilage held the jaw in place- but then the rotting cartilage gave way, and the jaw creaked open, as if the fleshless child were trying to say something to her. But the gaping smile kept widening, grotesquely, and a fat worm wriggled where the tongue had been, and then the jaw fell off, back into the dirt.

That didn't matter. He didn't need a jaw. What were a few teeth? She spat on the cranium and polished it clean of dirt with the palm of her hand. She cradled the skull, crooning.

When she returned to the lake, the people were waiting for her. They were all here, all but the youngest children and the mothers with infants. Some of the adults carried weapons- stone knives, wooden spears- as if Mother were a rogue bull elephant who might suddenly turn on them. But as many of the group were dismayed as were overtly hostile. Here was Sapling, for instance, his spear-thrower slung over his back on a length of sinew, his pale eyes clouded as he watched the woman who had taught him so much. Many of them even wore the markings she had inspired on their flesh or clothes.

Sour's only surviving child was a girl, thirteen years old. She had always been prone to chubbiness, and that had gotten worse now that she was coming into womanhood; already her breasts were large, pendulous. And her skin was an odd yellow-brown color, like honey, the legacy of a chance meeting with a wandering group from the north a couple of generations back. Now this girl, Honey, Mother's cousin, stared at Mother with baffled anger, her dirty face streaked with tears.

Hostile, sad, pitying, or confused, they were all uncertain. When she recognized that uncertainty Mother felt a kind of inner warmth. Without yelling, without using violence, without so much as a gesture, she was in control of the situation.

She held up the skull and swiveled it so that its sightless eyes turned on the people. They gasped and flinched- but most looked more baffled than frightened. What use was an old skull?

But one girl turned away, as if the staring skull were looking at her accusingly. She was a skinny, intense fourteen-year-old with wide eyes. This girl, Eyes, had a particularly elaborate spiral design sketched on her upper arms in ocher. Mother made a mental note of her.

One man stepped forward. He was a huge fellow with a ferocious temper, like a cornered ox. Now Ox pointed back at Sour's shelter. "Dead," he said. He pointed his ax at Mother. "You. Head, rock. Why Why?"

For all the control she was exerting on the situation, Mother knew that what she said now would determine her entire future. If she was driven out of the camp she could not expect to survive long.

But she was confident.

She looked at the skull, and smiled. Then she pointed at Sour's body. "She kill boy. She kill him him."

Ox's black eyes narrowed. If that was true that Sour had killed the boy, then Mother's actions could be justified. Any mother, even a father, would be expected to avenge a murdered child.

But now Honey pushed forward. "How, how, how?" Struggling to express herself, her plump belly wobbling, she mimed stabbing, strangling. "Not kill. Not touch. How, how, how? Boy sick. Boy die. How, how?" How is my mother supposed to have done this? How is my mother supposed to have done this?

Mother raised her face to the sun, which sailed through a cloudless dome of white-blue sky. "Hot," she said, wiping her brow. "Sun hot. Sun not touch. She She not touch. not touch. She She kill." kill." Action at a distance. It isn't necessary for the sun to touch your flesh for it to warm you. And it wasn't necessary for Sour to touch my son to kill him. Action at a distance. It isn't necessary for the sun to touch your flesh for it to warm you. And it wasn't necessary for Sour to touch my son to kill him.

There was fear in their faces now. There were plenty of invisible, incomprehensible killers in their lives. But the notion that a person could control control such forces was new, frightening. such forces was new, frightening.

Mother forced herself to smile. "Safe. She dead. Safe now." I killed her for you. I killed the demon. Trust me. I killed her for you. I killed the demon. Trust me. She held up the skull, stroking its cranium. "Tell me." And so it had been. She held up the skull, stroking its cranium. "Tell me." And so it had been.

Ox glared at Mother. He growled and stamped, and pointed at her chest with his ax. "Boy dead. dead. Not tell. Boy dead." Not tell. Boy dead."

She smiled. She nestled the skull in the crook of her arm, like the head of a baby. And as they stared at her, half-believing, she could feel her power spread.

But Honey wouldn't accept any of this. Crying, jabbering meaninglessly, she lunged at Mother. But the women held her back.

Mother walked away toward her shelter. The people shrank back as she passed, eyes wide.

III.

The dryness intensified. One hot, cloudless day gave way to another. The land dried quickly, the streams shriveling to brownish trickles. The plants died back, though there were still roots to be dug out with ingenuity and strength. The hunters had to range far in search of meat, their feet pounding over dusty baked-dry ground.

These were people who lived in the open, with the land, the sky, the air. They were sensitive to the changes in the world around them. And they all quickly knew that the drought was deepening.