When she opened her eyes, the Weapon was floating above her.

It was a sphere as wide as a human was tall, reflective as a mirror, hovering at waist height above the smooth surface of the Platform. She could see herself in the thing's heavy silver belly, on her back on the heap of blankets, her baby asleep in the cot beside her. A small hatch was open in its flank, an opening with lobed lips, like a mouth. From this hatch a silvery tongue, meters long, reached out and snaked to the back of the neck of the small boy who stood beside the sphere.

Her aunt, her father, the others hung back, nervous of this ma.s.sive presence that dominated all their lives.

The boy attached to the tongue-umbilical took a step towards the cot.

Telni blocked his way. "Stay back, Powpy, you little monster. You were once a boy as I was. Now I am old and you are young. Stay away from my grandson."

Powpy halted. Ama saw that his eyes flickered nervously, glancing at Telni, the cot, the Weapon. This showed the extent of the Weapon's control of its human creature; somewhere in there was a frightened child.

Ama struggled to sit up. "What do you want?"

The boy Powpy turned to her. "We wish to know why you wanted to give birth within a Building."

"You know why," she snapped back. "No child born inside a Building has ever harbored an Effigy."

The child's voice was flat, neutral his accent like her father's, she thought, a little boy with the intonation of an older generation. "A child without an Effigy is less than a child with an Effigy. Human custom concurs with that, even without understanding "

"I didn't want you you to be interested in him." The words came in a rush. "You control us. You keep us here floating in the sky. All for the Effigies we harbor, or not. That's what you're interested in, isn't it?" Telni laid a trembling hand on her arm, but she shook it away. "My husband believed his life was pointless, that his only purpose was to grow old and die for you. In the end he destroyed himself " to be interested in him." The words came in a rush. "You control us. You keep us here floating in the sky. All for the Effigies we harbor, or not. That's what you're interested in, isn't it?" Telni laid a trembling hand on her arm, but she shook it away. "My husband believed his life was pointless, that his only purpose was to grow old and die for you. In the end he destroyed himself "

"Addled by the drink," murmured Telni.

"He didn't want you you to benefit from his death. He never even saw this baby, his son. He wanted more than this!" to benefit from his death. He never even saw this baby, his son. He wanted more than this!"

The Weapon seemed to consider this. "We intend no harm. On the contrary, a proper study of the symbiotic relationship between humans and Effigies "

"Go away," she said. She found she was choking back tears. "Go away!" And she flung a blanket at its impa.s.sive hide, for that was all she had to throw.

The Weapon came to see Telni a few days after the funeral of his mother and grandfather. He was ten years old.

Telni had had to endure a vigil beside the bodies, where they had been laid out close to the rim of the Platform. He slept a lot, huddled against his kind but severe aunt Jurg, his last surviving relative.

At the dawn of the third day, as the light-storms down on the Lowland glimmered and shifted and filled the air with their pearly glow, Jurg prodded him awake. And, he saw, his mother was ascending. A cloud of pale mist burst soundlessly from the body on its pallet. It hovered, tendrils and billows pulsing and then, just for a heartbeat, it gathered itself into a form that was recognizably human, a misty sh.e.l.l with arms and legs, torso and head.

Jurg, Ama's sister, was crying. "She's smiling. Can you see? Oh, how wonderful..."

The sketch of Ama lengthened, her neck stretching like a spindling's, becoming impossibly long. Then the distorted Effigy shot up into the blueshifted sky and arced down over the lip of the Platform, hurling itself into the flickering crimson of the plain below. Jurg told Telni that Ama's Effigy was seeking its final lodging deep in the slow-beating heart of Old Earth, where, so it was believed, something of Ama would survive even the Formidable Caresses. But Telni knew that Ama had despised the Effigies, even the one that turned out to have resided in her.

They waited another day, but no Effigy emerged from old Telni. So the bodies were taken across the Platform, to the center of the cl.u.s.ter of box-shaped, blank-walled Buildings, and placed reverently inside one of the smaller structures. A week later, when Jurg took Telni to see, the bodies were entirely vanished, their substance subsumed by the Building, which might have become a fraction larger after its ingestion.

So Telni, orphaned, was left in the care of his aunt.

She tried to get him to return to his schooling. A thousand people lived on the Platform, of which a few hundred were children; the schools were efficient and well organized. But Telni, driven by feelings too complicated to face, was restless. He roamed, alone, through the forest of Buildings. Or he would stand at the edge of the Platform, before the gulf that surrounded the floating city, and watch the Shelf war unfold, accelerated by its alt.i.tude, the pale blue explosions and whizzing aircraft making an endless spectacle. He was aware that his aunt and teachers and the other adults were watching him, concerned, but for now they gave him his head.

On the third day he made for one of his favorite places, which was the big wheel at the very center of the Platform, turned endlessly by harnessed spindlings. Here you could look down through a hatch in the Platform, a hole in the floor of the world, and follow the tethers that attached the Platform like a huge kite to the Lowland ground half a kilometer below, and watch the bucket chains rising and falling. The Loading Hub was directly beneath the Platform, the convergence of a dozen roads crowded day and night. Standing here it was as if you could see the machinery of the world working. He liked to think about such things, as a distraction from thinking about other things. And it pleased him in other ways he didn't really understand, as if he had a deep, sunken memory of much bigger, more complicated machinery than this.

Best of all you could visit the spindling pens and help the cargo jockeys muck out a tall beast, and brush the fur on its six powerful legs, and feed it the strange purple-colored straw it preferred. The spindlings saw him cry a few times, but n.o.body else, not even his aunt.

When the Weapon came to see him he was alone in one of the smaller Buildings, near the center of the cl.u.s.ter on the Platform. He was watching the slow crawl of lightmoss across the wall, the glow it cast subtly shifting. It was as if the Weapon just appeared at the door. Its little boy stood at its side, Powpy, with the cable dangling from the back of his neck.

Telni stared at the boy. "He used to be bigger than me. The boy. Now he's smaller."

"We believe you understand why," said Powpy.

"The last time I saw you was four years ago. I was six. I've grown since then. But you live down on the Lowland, mostly. Did you come up in one of the freight buckets?"

"No."

"You live slower down there."

"Do you know how much slower?"

"No."

The boy nodded stiffly, as if somebody was pushing the back of his head. "A straightforward, honest answer. The Lowland here is deep, about half a kilometer below the Platform, which is itself over three hundred meters below the Shelf. Locally the stratification of time has a gradient of, approximately, five parts in one hundred per meter. So a year on the Platform is "

"Only a couple of weeks on the Lowland. But, umm, three hundred times five, a year here is fifteen years on the Shelf."

"Actually closer to seventeen. Do you know why why time is stratified?" time is stratified?"

"I don't know that word."

Powpy's little mouth had stumbled on it too, and other hard words. "Layered."

"No."

"Good. Nor do we. Do you know why your mother died?"

That blunt question made him gasp. Since Ama had gone, n.o.body had even mentioned her name. "It was the refugees' plague. She died of that. And my grandfather died soon after. My aunt Jurg says it was of a broken heart."

"Why did the plague come here?"

"The refugees brought it. Refugees from the war on the Shelf. The war's gone on for years, Shelf years. My grandfather says said it is as if they are trying to bring down a Formidable Caress of their own. The refugees came in a balloon. Families with kids. Grandfather says it happens every so often. They don't know what the Platform is, but they see it hanging in the air, below them, at peace. So they try to escape."

"Were they sick when they arrived?"

"No. But they carried the plague bugs. People started dying. They weren't im "

"Immune."

"Immune like the refugees."

"Why not?"

"Time goes faster up on the Shelf. Bugs change quickly. You get used to one, but then another comes along."

"Your understanding is clear."

"My mother hated you. She was unhappy when you visited me that time, when I was six. She says you meddle in our lives."

"'Meddle.' We created the Platform, gathered the sentient Buildings. We designed this community. Your life, and the lives of many generations of your ancestors, have been shaped by what we built. We 'meddled' long before you were born."

"Why?"

Silence again. "That's too big a question. Ask smaller questions."

"Why are there so many roads coming in across the Lowland to the Loading Hub?"

"I think you know the answer to that."

"Time goes twenty-five times slower down there. It's as if you're trying to feed a city twenty-five times the size."

"That's right. Now ask about something you don't know."

He pointed to the lightmoss. "Is this the same stuff as makes the light-storms, down on the Lowland?"

"Yes, it is. That's a good observation. To connect two such apparently disparate phenomena "

"I tried to eat the lightmoss. I threw it up. You can't eat the spindlings' straw either. Why?"

"Because they come from other places. Other worlds than this. Whole other systems of life."

Telni understood some of this. "People brought them here, and mixed everything up." A thought struck him. "Can spindlings eat lightmoss?"

"Why is that relevant?"

"Because if they can, it must mean they came from the same other place."

"You can find that out for yourself."

He itched to go try the experiment, right now. "Did people make you?"

"They made our grandfathers, if you like."

"Were you really weapons?"

"Not all of us. Such labels are irrelevant now. When human civilizations fell, sentient machines were left to roam, to interact. There was selection, of a brutal sort, as we competed for resources and spare parts. We enjoyed our own long evolution. A man called Bayle mounted an expedition to the Lowland, and found us."

"You were farming humans. That's what my mother said."

"It wasn't as simple as that. The interaction with Bayle's scholars led to a new generation with enhanced faculties."

"What kind of faculties?"

"Curiosity."

Telni considered that. "What's special about me? That I might have an Effigy inside me?"

"Not just that. Your mother rebelled when you were born. That's very rare. The human community here was founded from a pool of scholars, but that was many generations ago. We fear that we may have bred out a certain initiative. That was how you came to our attention, Telni. There may be questions you can answer that we can't. There may be questions you can ask ask that we can't." that we can't."

"Like what?"

"You tell me."

He thought. "What are the Formidable Caresses?"

"The ends of the world. Or at least, of civilization. In the past, and in the future."

"How does time work?"

"That's another question you can answer yourself."

He was mystified. "How?"

A seam opened up on the Weapon's sleek side, like a wound, revealing a dark interior. Powpy had to push his little hand inside and grope around for something. Despite the Weapon's control, Telni could see his revulsion. He drew out something that gleamed, complex. He handed it to Telni.

Telni turned it over in his hands, fascinated. It was warm. "What is it?"

"A clock. A precise one. You'll work out what to do with it." The Weapon moved, gliding up another meter into the air. "One more question."

"Why do I feel ... sometimes..." It was hard to put into words. "Like I should be somewhere else? My mother said everybody feels like that, when they're young. But ... Is it a stupid question?"

"No. It is a very important question. But it is one you will have to answer for yourself. We will see you again." It drifted away, two meters up in the air, with the little boy running beneath, like a dog on a long lead. But it paused once more, and the boy turned. "What will you do now?"

Telni grinned. "Go feed moss to a spindling."

At twenty-five, Telni was the youngest of the Platform party selected to meet the Natural Philosophers from the Shelf, and MinaAndry, a year or two younger, was the most junior of the visitors from Foro. It was natural they would end up together.

The formal welcomes were made at the lip of the Platform, under the vast, astonishing bulk of the tethered airship. The Shelf folk looked as if they longed to be away from the edge, and the long drop to the Lowland below. Then the parties broke up for informal discussions and demonstrations. The groups, of fifty or so on each side, were to rea.s.semble for a formal dinner that night in the Hall, the largest and grandest of the Platform's sentient Buildings. Thus the month-long expedition by the Shelf Philosophers would begin to address its goals, the start of a cultural and philosophical exchange with the Platform. It was a fitting project. The inhabitants of the Platform, drawn long ago from Foro, were after all distant cousins of the Shelf folk.

And Telni found himself partnered with MinaAndry.

There was much good-natured ribbing at this, and not a little jealousy in the looks of the older men, Telni thought. But Mina was was beautiful. All the folk from the Shelf were handsome in their way, tall and elegant not quite of the same stock as the Platform folk, who, shorter and heavier-built, were themselves different from the darker folk of the Lowland. They were three human groups swimming through time at different rates; of course they would diverge. But whatever the strange physics behind it, MinaAndry was the most beautiful girl Telni had ever seen, tall yet athletic-looking with a loose physical grace, and blonde hair tied tightly back from a spindling-slim neck. beautiful. All the folk from the Shelf were handsome in their way, tall and elegant not quite of the same stock as the Platform folk, who, shorter and heavier-built, were themselves different from the darker folk of the Lowland. They were three human groups swimming through time at different rates; of course they would diverge. But whatever the strange physics behind it, MinaAndry was the most beautiful girl Telni had ever seen, tall yet athletic-looking with a loose physical grace, and blonde hair tied tightly back from a spindling-slim neck.

They walked across the Platform, through the city of living Buildings. It was a jumble of cubes and rhomboids, pyramids and tetrahedrons even one handsome dodecahedron. The walls were gleaming white surfaces, smooth to the touch, neither hot nor cold, and pierced by sharp-edged doorways and windows.

"This place is so strange." Mina ran her hand across the smooth surface of a Building. Within its bland surface, through an open door, could be glimpsed the signs of humanity, a bunk bed made of wood hauled up from the plain, a hearth, a cooking pot, cupboards and heaps of blankets and clothes, and outside a bucket to catch the rain. "We build things of stone, of concrete, or wood. But this this " "

"We didn't build these structures at all. The Buildings grew here. They bud from units we call Flowers, and soak up the light from the storms. Like the Weapons, the Buildings are technology gone wild, made things modified by time."

"It all feels new, although I suppose it's actually very old. Whereas Foro feels feels old. All that lichen-encrusted stone! It's like a vast tomb..." old. All that lichen-encrusted stone! It's like a vast tomb..."

But Telni knew that the town she called Foro was built on the ruins of a city itself called New New Foro, devastated during the war he remembered watching as a boy. He had naively expected the Shelf folk to be full of stories of that war when they came here. But the war was fifteen Platform years over, more than two hundred and fifty Shelf years, and what was a childhood memory to Telni was long-dead history to Mina. Foro, devastated during the war he remembered watching as a boy. He had naively expected the Shelf folk to be full of stories of that war when they came here. But the war was fifteen Platform years over, more than two hundred and fifty Shelf years, and what was a childhood memory to Telni was long-dead history to Mina.

"Is it true you feed your dead to the Buildings?" She asked this with a kind of frisson of horror.