"But," Bayle said, "if this is a journey of no return, it need not be a journey without an end.

"Look around you! We do not yet know who built this city, and why I have no doubt we will discover all this in the future. But we do know that it is empty it is empty. The spa.r.s.e population of the Lowland has never found the collective will to inhabit this place. But we can turn this sh.e.l.l into a city and with our industry and communal spirit, we will serve as a beacon for those who wander across the Lowland's plains. All this I have discussed at length with Sila.

"Our long journey ends here. This city, bequeathed to us by an unimaginable past, will host our future." He raised his hands; Enna had never seen him look more evangelical. "We have come home!"

He won a storm of applause. Sila surveyed the crowded room, that cold a.s.sessment dominating her expression and again Enna was sure she could smell the cold iron stench of raw meat.

At the end of the dinner, despite her anxiety and determination, Enna still couldn't get to talk to her father. Bayle apologized, but with silent admonishments, warned her off spoiling the mood he had so carefully built; she knew that as Expedition leader he believed that morale, ever fragile, was the most precious resource of all. It will keep until the morning, his expression told her.

Frustrated, deeply uneasy, she left the building, walked out of the city to her wagon, and threw herself into Tomm's arms. He seemed surprised by her pa.s.sion.

Wait until the morning. But when the morning came, the city was in chaos. But when the morning came, the city was in chaos.

They were woken by babbling voices. They hastily pulled on their clothes, and hurried out of the wagon.

Servants and Philosophers milled about, some only half-dressed. Enna found Nool, her father's manservant; disheveled, unshaven, he was nothing like the sleek major-domo of the dinner last night. "I'm not going back in there again," he said. "You can pay me what you like."

Enna grabbed his shoulders. "Nool! Calm down, man. Is it my father? Is something wrong?"

"The sooner we get loaded up and out of here the better, I say..."

Enna abandoned him and turned to Tomm. "We'll have to find him."

But Tomm was staring up at the sky. "By all that's created," he said. "Look at that."

At first she thought the shape drifting in the sky was the Expedition's balloon. But this angular, sharp-edged, white-walled object was no balloon. It was a building, a parallelepiped. With no signs of doors or windows, it had come loose of the ground, and drifted away on the wind like a soap bubble.

"I don't believe it," Tomm murmured.

Enna said grimly, "Right now we don't have time. Come on." She grabbed his hand and dragged him into the city.

The unmade streets were crowded today, and people swarmed; it was difficult to find a way through. And again she had that strange, dreamlike feeling that the layout of the city was different. "Tell me you see it too, cartographer," she demanded of Tomm. "It has changed, again."

"Yes, it has changed."

She was relieved to see her father's building was still where it had been. But Philosophers were milling about, helpless, wringing their hands.

The doors and windows, all of them, had sealed up. There was no way into the building, or out.

She shoved her way through the crowd, grabbing Philosophers. "Where is he? Is he in there?" But none of them had an answer. She reached the building itself. She ran her hands over the wall where the door had been last night, but it was seamless, as if the door had never existed. She slammed on the wall. "Father? Bayle! Can you hear me? It's Enna!" But there was no reply.

And then the wall lurched before her. Tomm s.n.a.t.c.hed her back. The whole building was shifting, she saw, as if restless to come loose of the ground.

When it settled she began to batter the wall again.

"He can't hear you." The woman, Sila, stood in the fine robes Bayle had given her. She seemed aloof, untouched.

Enna grabbed Sila by the shoulders and pushed her against the wall of the building. "What have you done?"

"Me? I haven't done anything." Sila was unperturbed by Enna's violence, though she was breathing hard. "But you know that, don't you?" Her voice was deep, exotic ancient as Lowland dust.

Desperate as Enna was to find her father, the pieces of the puzzle were sliding around in her head. "This is all about the buildings, isn't it?"

"You're a clever girl. Your father will be proud or would have been. He's probably already dead. Don't fret; he won't have suffered, much."

Tomm stood before them, uncertain. "I don't understand any of this. Has this woman harmed Bayle?"

"No," Enna hissed. "You just lured him here didn't you, you witch? It's the building, Tomm. That's what's important here, not this woman."

"The building?"

"The buildings take meat," Sila said. "Somehow they use it to maintain their fabric. Don't ask me how."

Tomm asked, "Meat?"

"And light," Enna said. "That's why they stack up into this strange reef, isn't it? It isn't a human architecture at all, is it? The buildings are competing for the light. The buildings are competing for the light."

Sila smiled. "You see, I said you were clever."

"The light?"

"Oh, Tomm, don't just repeat everything we say! He's in there. My father. And we've got to get him out."

Tomm was obviously bewildered. "If you say so. How?"

She thought fast. Buildings that take meat. Buildings that need light ... "The balloon," she said. "Get some servants."

"It will take an age for the heaters "

"Just bring the envelope. Hurry, Tomm!"

Tomm rushed off.

Enna went back to the building and continued to slam her hand against the wall. "I'll get you out of there, father. Hold on!" But there was no reply. And again the building shifted ominously, its base sc.r.a.ping over the ground. She glanced into the sky, where that flying building had already become a speck against the blueshifted stars. If they fed, if they had the light they needed, did the buildings simply float away in search of new prey? Was that what had become of poor Momo?

Tomm returned with the balloon envelope, manhandled by a dozen bearers.

"Get it over the building," Enna ordered. "Block out the light. Hurry. Oh, please..."

All of them hauled at the balloon envelope, dragging it over the building. The envelope ripped on the sharp corners of the building, but Enna ignored wails of protest from the Philosophers. At last the thick hide envelope covered the building from top to bottom; it was like a wrapped-up present. She stood back, breathing hard, her hands stinking of leather. She had no idea what to do next if this didn't work.

A door dilated open in the side of the building. Fumes billowed out, hot and yellow, and people recoiled, coughing and pressing their eyes. Then Bayle came staggering out of the building, and collapsed to the ground.

"Father!" Enna got to the ground and took his head on her lap.

His clothes were shredded, his hands were folded up like claws, and the skin of his face was crimson. But he was alive. "It was an acid bath in there," he wheezed. "Another few moments and I would have succ.u.mbed. It was like being swallowed. Digested."

"I know," she said.

He looked up; his eyes had been spared the acid. "You understand?"

"I think so. Father, we have to let the doctors see to you."

"Yes, yes ... but first, get everybody out of this cursed place."

Enna glanced up at Tomm, who turned away and began to shout commands.

"And," wheezed Bayle, "where is that woman, Sila?"

There was a waft of acid-laden air, a ripping noise. Philosophers scrambled back out of the way. Cradling her father, Enna saw that the building had shaken off the balloon envelope and was lifting grandly into the air.

Sila sat in an open doorway, looking down impa.s.sively, as the building lifted her into the time-accelerated sky.

Bayle was taken to his wagon, where his wounds were treated. He allowed in n.o.body but his daughter, the doctors, Nool and Tomm, who he said had acquitted himself well.

Even in this straitened circ.u.mstance Bayle held forth, his voice reduced to a whisper, his face swathed in unguent cream. "I blame myself," he said. "I let myself see what I wanted to see about this city just as I pompously warned you, Tomm, against the self-same flaw. And I refused to listen to you, Enna. I wanted to see a haven for the people I have led out into the wilderness. I saw what did not exist."

"You saw what Sila wanted you to see," Enna said.

"Ah, Sila ... What an enigma! But the fault is mine, Enna; you won't talk me out of that."

"And the buildings "

"I should have seen the pattern before you! After all, we have a precedent. The Weapons are technology gone wild, made things modified by time and so are the buildings of this 'city.'"

Once, surely, the buildings had been intended to house people. But they were advanced technology: mobile, self-maintaining. They fuelled themselves with light, and with organic traces perhaps they had been designed to process their occupants' waste.

Things changed. People abandoned the buildings, and forgot about them. But the buildings, self-maintaining, perhaps even self-aware in some rudimentary sense, sought a new way to live and that way diverged ever more greatly from the purposes their human inventors had imagined.

"They came together for protection," Bayle whispered. "They huddled together in reefs that look like towns, cities, jostling for light. And then they discovered a new strategy, when the first ragged human beings innocently entered their doorways."

The buildings apparently offered shelter. And when a human was foolish enough to accept that mute offer "They feed," said Tomm with horror.

Bayle said, "It is just as the wild Weapons once learned to farm humans for meat. We have seen this before. We share a world with technology that has gone wild and undergone its own evolution. I should have known!"

Enna said, "And Sila?"

"Now she is more interesting," Bayle whispered. "She told me exactly what I wanted to hear fool as I was to listen! She cooperates with the city, you see; in return for shelter perhaps even for some grisly form of food she helps it lure in unwitting travelers, like us. Her presence makes it seem safer than a city empty altogether."

"A symbiosis," Tomm said, wondering. "Of humans with wild technology."

Enna shuddered. "We have had a narrow escape."

Bayle covered her hand with his own bandaged fingers. "But others, like poor Momo, have died for my foolishness."

"We must go on," Tomm said. "There is nothing for us here."

"Nothing but a warning. Yes, we will go on. The Expedition continues! But not forever. Someday we will find a home "

"Or we will build one," Tomm said firmly.

Bayle nodded stiffly. "Yes. But that's for you youngsters, not for the likes of me."

Enna was moved to take Tomm's hand in hers.

Bayle watched them. "He may not have a first-cla.s.s mind," he said to Enna. "But he has an air of command, and that's worth cultivating."

"Oh, father "

Outside the wagon there came shouting, and a rushing sound, like great breaths being drawn.

"Go and see," Bayle whispered.

Enna and Bayle rushed out of the wagon.

Displacing air that washed over the people, the sentient buildings of the city were lifting off the ground, ma.s.sive, mobile. Already the first of them was high in the blueshifted sky, and the others followed in a stream of silent geometry, buildings blowing away like seeds on the breeze.

FORMIDABLE CARESS.

Some things are inherently beyond the scope of human experience unless there's a really big loophole.

As the women tried to pull her away, Ama hammered with her fist on the blank wall of the Building. "Let me inside! Oh, let me inside!"

But the Building had sealed itself against her. If the Weapon decreed that you were to have your child in the open air, that was how it was going to be, and no mere human being could do anything about it.

And she could not fight the logic of her body. The contractions came in pulses now, in waves that washed through the core of her being. In the end it was her father, Telni, who put his bony arm around her shoulders, murmuring small endearments. Exhausted, she allowed herself to be led away.

Telni's sister Jurg and the other women had set up a pallet for her not far from the rim of the Platform. They laid her down here and fussed with their blankets and buckets of warmed water, and prepared ancient knives for the cutting. Her aunt ma.s.saged her swollen belly with oils brought up from the Lowland. Telni propped her head on his arm, and held her hand tightly, but she could feel the weariness in his grip.

So it began. She breathed and screamed and pushed. And through it all, here at the lip of the Platform, she was surrounded by her world, the Buildings cl.u.s.tered around her, the red mist of the Lowland far below, above her the gaunt cliff on which glittered the blue-tinged lights of the Shelf cities, and the sky over her head where chains of stars curled like windblown hair. On Old Earth time was layered, and when she looked up she was peering up into accelerated time, at places where human hearts fluttered like songbirds'. But there was a personal dimension to time too, so her father had always taught her, and these hours of her labor were the longest of her life, as if her body had been dragged down into the glutinous, redshifted slowness of the Lowland.

When it was done, Jurg handed her the baby. It was a boy, a sc.r.a.p of flesh born a little early, his weight negligible inside the spindling-skin blankets. She immediately loved him unconditionally, whatever alien thing lay within. "I call him Telni like his grandfather," she managed to whisper.

Telni, exhausted himself, wiped tears from his crumpled cheeks.

She slept for a while, out in the open.