Xeelee: Endurance

The Lowland Expedition

AD c.4.8 Billion Years

Enna relished her flights in the spotting balloon.

She loved to see the Expedition train strung out across the Lowland’s arid plain, with its spindling-drawn wagons, the chains of servants and bearers, the gleaming coach that transported her father and his precious books, even the small flock of runner-birds. If the weather was fine the Philosophers themselves would walk alongside the wagons, marching into the Lowland’s mysteries, arguing endlessly. The Lowland Expedition was a grand gesture of the civilisation of the Shelf that had spawned it.

And it was brave too, for all the explorers knew that they could never go home again, whatever they discovered. Already the communities they had left had been whisked by stratified time into the deep past; the explorers would bring home their treasure of knowledge to their own remote descendants in an unknowable future.

Down there on the ground was Tomm, one of the junior cartographers. Whenever Enna flew, Tomm always wore a special red cap so she could pick him out, a bright-red dot in the dusty line of Philosophers. At twenty-one he was just a year older than Enna herself – and he was her lover, though that was a secret to all but her closest friends, and certainly to her father, or so she hoped. When he saw her, he waved.

But his waving was sluggish, like an old man’s. When she rode her balloon up into the air, Enna was ascending into quicker time. If Tomm’s ears had been sensitive enough he would have heard her heart fluttering like a bird’s, and conversely when she looked down at him she saw him slowed, trapped in glutinous, redshifted time.

The balloon flights were invaluable aids to navigation, but Bayle, Enna’s father, had strictly ordered that flights should be short, and that his party should take it in turns to man them, so that no one fell too far out of synchronisation with the rest. ‘This trip is challenging enough for us all,’ he insisted, ‘without the cogs of time slipping too.’ Enna accepted this wisdom. Even now, despite the joy of the flight, she longed to break through the barriers of streamed time that separated her from her love.

But when she spied the city on the horizon she forgot even Tomm.

The light of the Lowland was strange, shifting. Storms of light constantly swept across its surface, silent and flaring white. These founts of brightness were in fact the major source of daylight on Old Earth, but they made the seeing uncertain. Enna thought at first that the bright white line she spied on the horizon must be weather: a low cloud, a dust devil, even a minor light storm. But in a rare instant of clear seeing, the bright band resolved into a cluster of geometrical shapes, unmistakably artificial. It must be a city, stranded in the middle of the Lowland, where nobody had expected to find any signs of humanity but the meanest degradation. And Enna had discovered it.

She turned immediately to the pilot. ‘Do you see it? There, the city, can you see? Oh, take us down! Take us down!’

The expedition’s chief pilot was a bluff good-humoured fellow called Momo. A long-time military-service companion of her father, he was one of the few people to whom Bayle would entrust his daughter’s life. As he had lost one eye in the wars he ‘couldn’t see a blessed thing’, he told her. But he believed her, and began to tug on the ropes that controlled the hot-air balloon’s burner.

Enna leaned over the descending gondola, yelling out news of her discovery. As the time differentials melted away, faces turned slowly up towards her.

The Philosophers entered the city in wonder. Enna walked hand in hand with Tomm.

The city was a jumble of cubes and rhomboids, pyramids and tetrahedrons – even one handsome dodecahedron. The buildings towered over the explorers, immense blocks of a geometric perfection that would have shamed even the grand civic centre of New Foro, Enna thought.

There were no doors, though, and the windows weren’t glazed. And there were plenty of other peculiarities. Without inner partitions, each building was like ‘one big room’, as Tomm put it. Between the buildings the ground was just dirt, not paved or cobbled as were the streets of New Foro, back on the Shelf. It was more abstract than any city Enna had seen before, more like an art installation perhaps. And yet these great structures were clearly habitable.

‘And there’s nobody here,’ Enna whispered. ‘Not a soul! It’s so strange.’

‘But wonderful,’ Tomm said. He was tall, strong but sparsely built, with a languid grace that disturbed her dreams. ‘This must be a terribly ancient place. Look at the finish of these walls – what is this stuff, stone, ceramic, glass? Far beyond anything we are capable of. Perhaps the builders were Weapon-makers.’

‘Maybe, but don’t you think it’s all rather eerie? And the layout is such a jumble—’

‘A cartographer’s nightmare.’ Tomm laughed.

‘And why are there no windows or doors?’

‘We can make windows,’ he said. ‘We can hang doors.’ He took her hands. ‘Questions, questions, Enna! You’re worse than all these grumpy old Philosophers. This is your discovery. Relish the moment!’

There was a deep harrumph. Bayle, Enna’s father, came walking towards them, trailed by acolytes, lesser men but Philosophers themselves. Tomm hastily released Enna’s hands.

‘But Enna is right,’ Bayle said. ‘There is some familiarity about the place, and yet perhaps that merely blinds us to how much is strange . . .’

Bayle wore his dress uniform, topped off by his cap of spindling fur and feathers. Though he had devoted the last three decades of his life to science, Bayle had retained an honorary rank in the army of New Foro, and ‘for the sake of general morale’, as he put it, he donned his uniform to mark moments of particular significance during their long journey. But Enna knew that no matter how extravagant his appearance, her father’s mind was sharper than any of those around him.

He tapped the walls of the nearest building with his stick. ‘Certainly the layout follows no obvious rational design, as does the centre of New Foro, say. But there are patterns here.’ He walked them briskly through the narrow alleys between the buildings. ‘Can you see how the largest buildings are clustered on the outside, and the smaller huts are in their shade?’

‘It almost looks organic,’ Enna said impulsively. ‘Like a forest, dominated by its tallest trees.’

Bayle eyed her appreciatively. ‘I was going to compare it to a bank of salt crystals.’ Salt had become something of an obsession of Bayle’s during their journey. There was salt everywhere in the Lowlands; there were even plains covered with the stuff, the relics of dried-up lakes. Bayle was gathering evidence for his contention that the Lowland had once been the bed of a mighty body of water. ‘But I admit, daughter, that your analogy may be more apt. This city is not planned as we think of it. It is almost as if it has grown here.’

Tomm seemed confused. ‘But that’s just an analogy. I mean, this is a city, built by human hands – though maybe long ago. That much is obvious, isn’t it?’

Bayle snapped, ‘If everything were obvious we would not have needed to come out here to study it.’ He gave Enna a look that spoke volumes. The boy has a pretty face but a shallow mind, said that withering expression. You can do better.

But Tomm was Enna’s choice, and she returned his glare defiantly.

They were interrupted by a raucous hail. ‘Sir, sir! Look what I’ve found!’ It was Momo. The burly, one-eyed pilot came stumbling around the corner of a building.

And walking with him was a woman. Dressed in some kind of scraped animal skin, she was tall, aged perhaps fifty, in her way elegant despite her ragged costume. She eyed the Philosophers, detached. In that first moment Enna thought she seemed as cold, strange and hard-edged as her city.

Bayle stepped forward, his gloved hand extended. ‘Madam,’ he said, ‘if you can understand me, we have a great deal to discuss.’ The woman took Bayle’s hand and shook it. The subordinate Philosophers applauded enthusiastically.

It was yet another remarkable moment in this unprecedented trek of discovery. This was Bayle’s first contact with any of the ‘lost souls’ believed to inhabit the Lowland, stranded here from ages past; to find such people and ‘rehabilitate’ them had been one of his stated goals from the beginning.

But Enna caught a strange whiff about the woman, an iron stink that at first she couldn’t place. It was only later that she realised it was the smell of raw meat – of blood.

As night fell, the explorers and their attendants and servants dispersed gladly into the city’s bare buildings. After the dirt of the plain, it was going to be a relief to spend a night within solid walls.

Bayle himself established his base in one of the grander buildings on the edge of the city, bathed in light even at the end of the day. It seemed he planned to spend most of the night in conversation with the woman who was, as far as anybody could tell, the city’s sole inhabitant; he said they had much to learn from each other. He kissed his daughter goodnight, trusting her safety to his companions, and to her own common sense.

So it was a betrayal of him, of a sort, when in the darkest night Enna sought out Tomm’s warm arms. It wasn’t hard for her to put her guilt aside; at twenty she had a healthy awareness of how far her father’s opinions should govern her life.

But she dreamed. She dreamed that the building itself gathered her up and lifted her into the sky, just as she was cradled by Tomm’s arms – and she thought she smelled that iron tang again, the scent of blood.

The dream became disturbing, a dream of confinement.

Bayle had formulated many objectives for his Expedition.

Always visible from Foro, Puul and the other towns of the Shelf, the Lowland, stretching away below in redshifted ambiguity, had been a mystery throughout history. Now that mystery would be dispelled. Cartographers would map the Lowland. Historians, anthropologists and moralists hoped to make contact with the lost people of the Lowland plains, if any survived. Clerics, mystics, doctors and other Philosophers hoped to learn something about Effigies, those spectral apparitions that rose from dying human bodies, or some of them, and fled to the redshifted mysteries of the Lowland. Perhaps some insight would be gained into the cause of the Formidable Caresses, the tremendous rattlings that regularly shook human civilisation to pieces. There were even a few soldiers and armourers, hoping to track down Weapons, ancient technology gone wild, too wily to have been captured so far.

There had already been many successes. Take the light storms, for instance.

Old Earth’s blueshifted sky was a dome of stars that spun around the world. Day and night, and the seasons of the year, were governed not by the sky but by the flickering uncertainties of the light that emanated from the Lowland. Now Bayle’s physicists had discovered that these waves of light pulsed at many frequencies, ‘like the harmonics of a plucked string,’ as one mathematician had described it. Not only that, because of the redshifting of the light that struggled up to higher altitudes, the harmonic peaks that governed the daily cycles here were different from those to be observed from Foro, up on the Shelf, where time ran faster.

Enna was walked through the logic by her father. The effects of time stratification, redshifting and light cycling subtly intermeshed, so that whether you were up on the Shelf or down in the Lowland the length of day and night you perceived was roughly similar. This surely couldn’t be a coincidence. As Bayle said, ‘It adds up to a remarkable mathematical argument for the whole world having been designed to be habitable by people and their creatures.’

That, of course, had provoked a lively debate.

Forons were traditionally Mechanists, adhering to a strand of natural philosophy that held that there was no governing mind behind the world, that everything about it had emerged from the blind working-out of natural laws – like the growth of a salt crystal, say, rather than the purposeful construction of a machine. However, there were hard-line Creationists who argued that everything on Old Earth required a purposeful explanation.

After centuries of debate a certain compromise view had emerged, it seemed to Enna, a melding of extreme viewpoints based on the evidence. Even the most ardent Mechanists had been forced to accept that the world contained overwhelming evidence that it had been manufactured, or at least heavily engineered. But if Old Earth was a machine, it was a very old machine, and in the ages since its formation, natural processes of the kind argued for by the Mechanists had surely operated to modify the world. Old Earth was a machine that had evolved.

At the heart of Bayle’s expedition was a deep ambition to reconcile the two great poles of human thought, the Mechanist versus the Creationist – and to end centuries of theological conflict over which too much blood had been spilled. He and his companions would see through this goal, even though they could only return to a distant future.

In the morning Enna and Tomm were among the first to stir. They emerged from their respective buildings, and greeted each other with a jolly innocence that probably fooled nobody.

Cartographer Tomm had been detailed to take up the balloon for a rapid aerial survey, to provide context for the more painstaking work on the ground. Enna, free of specific chores, decided to ride up with him.

But there was a problem. They couldn’t find Momo. The pilot was a habitual early riser, like Bayle himself – a relic from his military days, it seemed. He was always up for Enna.

Tomm was unconcerned. ‘So old One-eye treated himself to a party last night. He won’t be the only one—’

‘That isn’t like Momo!’ Enna snapped, growing impatient. When Tomm treated her like a foolish child, Enna had some sympathy for her father’s view of him. ‘Look, this is a strange city, which we barely explored before splitting up. You can help me find Momo, or use the hot air you’re spouting to go blow up the balloon yourself.’

He was crestfallen, but when she stalked off to search, Tomm, embarrassed, hurried after her.

She thought she remembered the building Momo had chosen as his shelter. She headed that way now.

But something was wrong. As she followed the unpaved alleys, the layout of the buildings didn’t quite match her memory of the night before. Of course, she had only had a quick glimpse of the city, and the light of morning, playing over these crisp creamy walls, was quite different. But even so, she wouldn’t have expected to get as lost as this.

And when she came to the place where she thought Momo’s building should have been, there was only a blank space. She walked back and forth over the bare ground, disoriented, dread gathering in her soul.

‘You must be mistaken,’ Tomm insisted.

‘I’m good at direction-finding, Tomm. You know that.’

Playfully he said, ‘You found your way to my bed well enough—’

‘Oh, shut up. This is serious. This is where Momo’s shelter was, I’m sure of it. Something has changed. I can feel it.’

Tomm said defensively, ‘That doesn’t sound very scientific.’

‘Then help me, o great cartographer. Did any of you make a map last night?’

‘Of course not. The light was poor. We knew there would be time enough today.’

She glared at him. But she was being unfair; it was a perfectly reasonable assumption that a city like this wouldn’t change overnight.

But the fact of the matter was, Momo was still missing.

Growing increasingly disturbed, she went to her father’s room. That at least was just where it had been last night. But her father wouldn’t see her; a busybody junior Philosopher barred her from even entering the door. Bayle was still deep in discussion with Sila, the ragged city woman, and he had left strict instructions to be disturbed by nobody – not even Enna, his daughter.

Tomm, apologetically, said he had to get on with his flight, Momo or no Momo. Distracted, Enna kissed him goodbye, and continued her search.

In the hours that followed, she walked the length and breadth of the city. She didn’t find Momo. But she did learn that he wasn’t the only missing person; two others had vanished, both servants. Though a few people were troubled, most seemed sure it was just a case of getting lost in a strange city. And as for the uncertain layout, she saw doubt in a few eyes. But the Philosophers, far better educated than she was, had no room in their heads for such strange and confusing notions as an indeterminate geography.

When Tomm went sailing over the city in his balloon, a junior pilot at his side, she dutifully wore the red cap so he could see her, down here on the ground. Time-accelerated, he waved like a jerky puppet. But still she couldn’t find Momo, or dispel her feeling of disquiet.

That evening, to her astonishment, her father let it be known that he was hosting a dinner – and Sila, the ragged city woman, was to be guest of honour.

Enna couldn’t remember her father showing such crass misjudgement before, and she wondered if he had somehow been seduced by this exotic city of the Lowland, or, worse, by the woman, Sila, of whom Enna knew nothing at all. But still Bayle’s entourage would not let Enna near her father; he was much too busy for mere family.

Enna made the best of it. She put on the finest dress in her luggage, and decorated her hair with her best jewellery, including the pretty piece her mother had given her when they bade their tearful goodbyes. But as she brushed her hair by the light of her spindling-fat lamp, the blank walls of the city building she was using seemed to close in around her.

She met Tomm outside the building. He was still in his travelling clothes; he had not been invited to the dinner.

‘You look wonderful,’ he said.

She knew he meant it, and her heart softened. ‘Thank you.’ She let him kiss her.

‘Do you suppose I’m allowed to walk you over?’

‘I’d like that. But, Tomm—’ She glanced back at the building, the gaping unglazed windows like eye sockets. ‘Put my luggage back in one of our wagons. I don’t care which one. I’m not spending another night in one of these boxes.’

‘Ah. Not even with me?’

‘Not even with you. I’m sorry, Tomm.’

‘Don’t be. As long as you let me share your wagon.’

When they got to her father’s building she was stunned by the sight. Inside, three long trestle-tables had been set up and laid with cloths and the best cutlery and china. Candles glowed on the tables, and finely dressed guests had already taken their seats. At the head table sat Bayle himself, with his closest confidantes – and his guest of honour, Sila, dressed now in a fine flowing black robe, sat beside him. From a smaller building co-opted as a kitchen, a steamy smell of vegetables emanated, while five fat runner-chicks slowly roasted on spits. Enna had grown up in a world shaped by her father’s organisational skills, of which the Expedition was perhaps the crowning glory. But even she was impressed by the speed and skill with which this event had been assembled. After all, the party had only reached this mysterious Lowland city a day before.

When he saw Enna, Bayle stood up and waved her forward. Led by Nool, Bayle’s sleek manservant, Enna took her place at her father’s right-hand side. Sila sat on his left.

Enna leaned close to her father. ‘I’ve got to talk to you. I’ve been trying all day.’

‘I know you have. Priorities, my dear.’

That was a word she had heard all her life. But she insisted, ‘Something isn’t right here. People are missing. The geography—’

He cut her off with a wave of his hand. ‘I know you’re no fool, my daughter, and I will hear you out. But not now. We’ll make time at the end of the dinner.’

She wasn’t going to get any more from him. But as her father sat back, she caught the eye of the city woman, Sila. She imagined there was a calculation in Sila’s deep gaze as it met her own. She wondered what Sila truly wanted – and what it would cost them all if she achieved it.

The food was good, of course; her father would have allowed nothing less, and the wine flowed voluminously, though Enna refused to touch a drop. She longed for the meal to be over, so she could talk to Bayle before another night fell. At last the final dish was cleared away, the glasses refilled for the final time.

And, to Enna’s intense frustration, Bayle got to his feet and began to make a speech.

He had spent the night and much of the day in conversation with Sila, he said, and a remarkable experience it had been.

Everybody had expected to find people down here on the Lowland. For generations the judges of Foro had used ‘time pits’ as a punishment measure. The logic was simple. The deeper you fell, the slower time passed for you, so by being hurled into the time pits you were banished to the future. Only a handful had ever climbed back up, bewilderingly displaced in time. But as time had gone by, rumours wafted up to the Shelf that some, at least, of the criminals of the past had survived, down there in their redshifted prison.

‘The time pits have long been stopped up,’ Bayle said now, ‘and we look back on such methods with shame. Now we long to discover what had become of our exiled citizens, and their offspring – and we long to reach out to them a hand of reason and hope. Our consciences would permit nothing less.

‘And now we have found those lost souls, in the person of Sila. She is the daughter of an exile, whose crime was political. Sila grew up almost in isolation with her mother, her only society a drifting, transient collection of refugees from many ages. And yet she is educated and articulate, with a sound moral compass; it would take very little grooming indeed for her to pass as a citizen of Foro.

‘There may be no society as we know it here, no government, no community. But the inhabitants of the Lowland are not animals but people, as we are. In her person Sila demonstrates the fundamental goodness of human nature, whatever its environment – and I for one applaud her for that.’

This was greeted by murmured appreciation and bangs of the tables. Sila looked out at the Philosophers, a small smile barely dissipating the coldness of her expression.

Now Bayle came to the emotional climax of his speech. ‘We all knew when we embarked from Foro that this would not just be an Expedition to the Lowland, but into time. We are all of us lost in the future, and with every day that passes here, the further that awful distance from home grows.’ He glanced at Enna, and she knew he was thinking of her mother, his wife, who had been too ill to travel with them on this journey – and who, as a consequence, Enna would never see again. ‘All of you made a sacrifice for knowledge, a sacrifice without precedent in the history of our civilisation.

‘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 place, and why – I have no doubt we will discover all this in the future. But we do know that it is empty. The sparse population of the Lowland has never found the collective will to inhabit this place. But we can turn this shell into a true 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. Oh, we will send emissaries back to our home on the Shelf – or the daughter civilisations of those we remember. But 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 assessment 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 apologised, but with silent admonishments, warned her about 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 passion.

Wait until the morning, Bayle had said.

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 alike milled about, some only half-dressed. Enna found Nool, her father’s manservant; dishevelled, 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, Tomm! My father—’

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, like a slanted cube. With no sign of doors or windows, it had come loose from the ground, and drifted away on the wind like a soap bubble.

‘I don’t believe it,’ Tomm murmured.

Enna said grimly, ‘Believe it or not, we have to find my father even so. 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. 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 wandering outside, 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 doorway had been last night, but it was seamless, as if the doorway 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 snatched her back. The whole building was shifting, she saw, as if restless to leave the ground. Still she called, ‘Father! Father!’

‘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.

Tomm looked bewildered. ‘Meat?’

‘Somehow they use it to maintain their fabric. Don’t ask me how.’

‘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? They are more like a forest. The buildings are competing for the light.’

Sila smiled. ‘You see, I said you were clever.’

‘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 scraping 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 structure, but Enna ignored wails of protest from the watching 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.

And 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, and collapsed to the ground.

‘Father!’ Enna knelt, 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 succumbed. 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. And Sila sat in an open doorway, looking down impassively, as the building lifted her into the time-accelerated sky.

Bayle was taken to his wagon, where his wounds were treated. He allowed in nobody but his daughter, the doctors, Nool – and Tomm, who, Bayle admitted grudgingly, had acquitted himself well.

Even in this straitened circumstance 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 did! After all, we have a precedent. The Weapons are technology gone wild, made things modified by time, grown into a kind of ecology – 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 habitats. 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 new 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 looked 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 whenever a human was foolish enough to accept that mute offer—’

‘They feed,’ said Tomm with horror.

Bayle said, ‘It is just as the Weapons of the plain once learned to farm humans for meat. 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 travellers, 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 for ever. 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-class 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 Tomm hurried out of the wagon.

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