Stacks didn’t want to go to the exhibition. He wasn’t busy, not since the money men had pulled the plug on the skylab, but rubbing shoulders with people who thought shadows burned into concrete counted as art wasn’t his idea of a good time. Still, his carbon balance didn’t care how he felt. It hovered above red, which meant he was a few weeks away from being crewed. He needed a new benefactor fast, so he shaved and put on his only clean suit and hopped onto the uptown transRapid.

       The exhibition, titled Spiritual Ethnos, was in a scraper in Stepney, overlooking a stretch of water where Limehouse had once been. It was a show Stacks would have found pretentious in his twenties and amusing in his thirties. Now, in his forties, the sight of human blood being injected into micrometeoroids failed to elicit any emotion. Perhaps there was significance to be found in the macabre. Or maybe it was indicative of the times. Stacks didn’t care either way.

       At the bar he touched his index finger to a scanner and a rolltender passed him a flute, and he leaned against polished chrome and took in the crowd. A good turnout. Dynamic suits mixed with static textile. Crisped skin looking taut and pure under careful spotlights. The scent of carbon in the air, like how a wad of paper money used to smell.

       These people lived in a different world, thought Stacks. Some knew as well as he that the ship was sinking and no half-baked statement on humankind’s resilience would arrest that. But most believed—truly believed—there was still time to bail out the water and right the ship. To be so dedicated to a mistruth took serious effort.  He admired them for it.

       Stacks raised his flute to the room and drank.

       Amid the faces a familiar one. Elewa Okigbo, head of Church, a quantum machine-learning coalition south of the river. Tall, elegant, serious, a spinner of many plates. She was in conversation with a heavyset man, and Stacks watched as Okigbo frowned in response to something the man said. Okigbo shook her head and the man laughed. Then he walked away, the back of his neck flushed.

       Stacks headed into the crowd. When he was close he said Okigbo’s name, and as she turned to him her severe expression softened.

       ‘Long time, Doctor Stackhouse.’

       She held her palm out in the dead space between them and Stacks did the same. He preferred to shake hands, but he was here to play ball.

       ‘I didn’t think Stepney was your style,’ she said.

       ‘Just checking in to see how the art world is interpreting the horrors of the modern world,’ said Stacks.

       Okigbo flagged a rolltender. ‘Drink?’

       ‘Please. A blacklight.’

       The tender dispensed the flute and he took it. Okigbo ordered a sparkling water. The rolltender scanned her and drifted away.

       ‘I heard what happened with Artsutanov,’ said Okigbo. ‘One in a million.’

       ‘Not quite,’ said Stacks. He’d talked about it so many times already. ‘We should have been able to drag the skylab out of the path of the satellite in time. It was the whole reason the thing was anchored at sea. But systems fail.’

       ‘Quite.’

       ‘How’s life on the quantum circuit?’

       Okigbo’s expression changed. ‘Not good. Church is strapped for carbon. We’re struggling to hold on to the hires we already have.’

       Stacks nodded. He’d always appreciated Okigbo’s directness. ‘There goes my consulting position,’ he said. ‘Is it so bad?’

       Okigbo shifted her sparkling water from one hand to the other. ‘It’s manageable.’ Her tone was unconvincing. ‘One of our key backers pulled out when Athos went bust. We’ve had to cut corners, disappoint stakeholders who’ll have to wait another few quarters before their carbon gets bumped.’

       She cleared her throat and blinked several times and Stacks noted a new intensity in her gaze. ‘Still,’ she said, ‘at least Castheiser will be here soon. When Castheiser arrives, we’ll be saved.’

       Stacks frowned. ‘Castheiser?’

       ‘There aren’t many things I believe in anymore, but Castheiser is one of them.’

       ‘Is that someone on your team? I’m afraid I don’t know who you mean.’

       Okigbo blinked again.

       ‘I’m sorry, Doctor,’ she said. ‘Lost my train of thought.’ She looked at the micrometeoroids being fed their vials of haemoglobin. ‘The strain is getting to me. My assistant encouraged me to take the evening off and dug out the invitation to this shindig.’

       ‘Castheiser?’ asked Stacks.

       ‘I’m sorry?’

       ‘Your assistant.’

       ‘My assistant’s name is Nowak,’ said Okigbo. ‘Hardworking boy.’ She smiled. ‘Keeps an eye on me though it isn’t his job.’

       ‘Then who is Castheiser?’ asked Stacks, trying and failing to keep the annoyance from his voice.

       ‘I have no idea,’ said Okigbo. She folded her arms. ‘If this is one of those modish surrealist jokes, Doctor, I’m afraid you have the wrong audience.’

       ‘You said it just now,’ said Stacks. ‘Castheiser is speeding things up for you.’ He paused. He’d wandered over hoping for a job, but was on the verge of arguing with the woman.

       ‘Perhaps you misheard me,’ said Okigbo. Her tone was dry.

       ‘Yes,’ said Stacks. He withdrew a handkerchief from his suit pocket and dabbed his brow. ‘I apologise. I hear one thing and my brain rushes off in ten different directions at once. Burden of being a scientist. Just the other day I could’ve sworn I heard a dog barking in the pod next to mine. Wouldn’t be able to get it through the front door without being evicted.’

       ‘Remarkable.’ Okigbo looked beyond him. ‘I’ve just spotted an old friend. Do you mind?’

       ‘Not at all,’ said Stacks. ‘Nobody wants a befuddled engineer talking their ear off all night.’ He gestured with his glass. ‘Thanks for the drink.’

       ‘Come to Church sometime,’ said Okigbo, already moving away, and Stacks didn’t bother to respond.

       He drained his blacklight, and a tender rolled over and he placed the glass on its head. The exhibition had been a bust. He took a last look at the rocks on their plinth, then went to retrieve his coat.

 

 

       

A week later, Stacks rode the pneumatic to Birmingham to keep a lunch date with an old colleague. Melchior, an expert in deep adaptation. In his shuttle, he read the news that work on the New Thames Barrier had been halted yet again due to a difference of opinion between the government and the principal contractor. Climate mitigation was one of the few industries left where there was carbon to be made. Even so, he couldn’t bring himself to go for it. Getting paid to put sticking plasters on festering wounds would make him no better than those who inflicted them.

       He emerged at New Street and walked the short distance to the restaurant behind the Bullring. Melchior was already waiting. They had studied together two decades previously, and still saw each other once a year. Melchior’s cheeks showed a whiskey glow, and he was evidently eating well.

       ‘Is it the fashion in London to look so pallid?’ asked Melchior after the two had embraced.

       ‘I’m not sleeping,’ said Stacks.

       ‘Why not?’

       ‘Pick a reason. You heard about the Barrier?’

       ‘Of course,’ said Melchior. ‘Not the first time and it won’t be the last.’

       ‘The prediction models think the next storm will wipe out half of London.’

       ‘Didn’t the last one do that already?’ Melchior laughed when he saw the look on Stacks’s face. ‘Oh, it’s no joking matter, I know. All those dead. But what else can one do? Better to see the humour in the situation than to fret.’

       ‘If you say so.’

       They ordered lunch and found enough conversation to tide them over until the food arrived. When Stacks was halfway through his plate—the cheapest on the menu—Melchior pounced.

       ‘You haven’t been working since Artsutanov went belly-up.’ He phrased it as a statement.

       ‘No,’ said Stacks.

       ‘City’s an expensive place to be without carbon.’

       Stacks didn’t answer.

       ‘I have a proposition,’ said Melchior. ‘You remember the unbearable temperatures last summer? Well, everyone running their air conditioners full tilt burned a huge hole in the carbon budget. The government isn’t going to stand for it this year.’

       ‘Melchior,’ warned Stacks.

       ‘Hear me out. We have more businesses coming to us about earthentecture. They don’t want to be slapped with fines. The demand is there for the rest of our lives, but I need capable hands to get our projects up and running. People I can trust not to drop the ball.’

       Stacks laughed.

       ‘What’s funny?’ asked Melchior.

       ‘I’m sorry.’ Stacks reached for his water glass, drank a mouthful and tasted chlorine. ‘When people talk about the rest of their lives these days, I wonder if they realise how long that is.’

       Melchior wrinkled his nose. ‘Don’t you understand the whole point of innovations like earthentecture and the New Thames Barrier is to create a future which is palatable for the majority?’

       Stacks smiled. ‘We’re just spinning the wheel because the wheel is still there to be spun. Only a matter of time before it’s taken off its axis.’

       Melchior threw up his hands. ‘And what about your skylab? How was that any different?’

       ‘I thought our salvation lay in the stars,’ said Stacks. ‘I was naïve.’

       ‘Correct.’

       Stacks was reminded again why he only saw the man once a year.

       Melchior leaned in, his gaze suddenly intense. ‘I’m about to let you in on the secret of a lifetime. I’m talking about Castheiser. When it arrives, we can cut through the red tape and the bluster and build for a better future. We can save ourselves.’

       Stacks swallowed. ‘Did you just say Castheiser?’

       ‘Castheiser can change the world,’ said Melchior. Then he sat back and blinked.

       ‘Melchior,’ said Stacks. ‘I want you to answer me this question: Who or what is Castheiser?’

       Melchior shook his head. ‘How do you mean?’

       ‘You just said, “Castheiser can change the world”.’

       ‘When?’ asked Melchior, frowning.

       ‘Five seconds ago,’ shouted Stacks. The restaurant fell quiet.

       ‘My dear boy,’ said Melchior, leaning in. ‘Please calm down. Explain to me what you mean and perhaps I can help you.’

       Stacks lowered his voice. ‘About a week ago I ran into someone who used the term Castheiser. Declared it to be some kind of saviour. Then she denied ever saying it. You did the same thing a moment ago.’

       ‘I did?’ asked Melchior.

       ‘Yes,’ said Stacks. He waited. At least the man wasn’t looking at him like he was crazy.

       ‘I’m not sure what to tell you,’ said Melchior. ‘I’ve never heard of any Castheiser. I once worked with a man named Konhauser. Photovoltaics whizz. Haven’t thought about him for years. Can’t imagine why I’d mention him out of the blue.’

       ‘It wasn’t Konhauser,’ said Stacks quietly. ‘It was Castheiser.’

       Melchior peered at him. ‘Are you sure you’re okay, old chap?’

       ‘I’m fine. I know what I heard.’

       ‘You know what you think you heard, in any case.’

       Stacks gritted his teeth. ‘Are you saying I have a screw loose?’

       ‘Not at all.’

       Stacks looked down at his plate. Then he stood. ‘I have to go.’

       ‘So soon? Will you think about my proposal? I’d love to have you on board.’

       ‘Climate mitigation isn’t for me.’

       There was something approaching pity in Melchior’s gaze. ‘Mitigation is all there is, my friend. The sooner you accept that, the easier it’ll be.’ He gestured at the food. ‘This is on me.’

       Stacks could barely bring himself to say thank you. He made for the door.

       ‘Take care, old man,’ Melchior called after him. ‘Get in touch if you change your mind.’

 

 

       

       In his pod Stacks booted the console he’d stolen from the skylab before the collectors had picked it clean. It was a prime model, with track-and-trace software that standard civilian variants didn’t have. He settled into his chair with a mug of ersatz and trawled the text-web for Castheiser.

       The results weren’t promising. Three pages of results, data quality eroding the further he scrolled. The top three hits were obituaries for men long dead, three brothers who had lived in Montana, Nebraska and Utah and died within ten years of one another. Then two listings in German which, when translated, proved to belong to a firm selling brass adapters for piping systems. And several results that contained the words ‘cast’ and ‘heiser’ separately.

       Stacks switched to the visual-web. Blue slabs rose from the console and hung in dead space. After making sure all track-and-trace extensions were activated, he fired off his search. The slabs divided and expanded and changed colour as the console sifted through yottabytes of data at a speed no human mind could comprehend.

       After two minutes, the console blinked. A single result hung suspended before him:

 

       Castheiser – 319-520-5188 – neural response – go-live 21/03

 

       It was buried deep within a concealed subdirectory listing business events in the United Kingdom. Stacks asked the console to trace where the entry had come from, but it came back blank. He ran the ten-digit number without success, then poked around the rest of the directory and found nothing.

       He cut the power and went to the pod’s ballistic windows and looked out at the midtown belt. The windows didn’t open all the way, but they tilted at the flick of a toggle. There was a dull ache in his gut, and it wasn’t because of the ersatz. Two people had mentioned Castheiser without being cognisant of the fact. Two people who didn’t relinquish control of anything if it wasn’t in their interest. The only result he’d found online was hidden so deep he’d needed prime T&T software to find it. Neural response. A string of digits. A date.

       His engineer’s mind blew hot and cold as it tried to find an angle. But either months of inactivity had dulled his senses or there simply wasn’t one. He watched as drones flew between biotecture scrapers, wondered if Castheiser was something to be feared or celebrated.

       He wouldn’t have to wait long to find out, he realised. The date was just over a week away.

 

 

       

       Whenever Stacks let his guard down, Castheiser was there.

       It happened in the transRapid as he headed uptown for an Artsutanov wind-up meeting. Two men, one young, one with salt-and-pepper hair, were in vague conversation near the door. Both had their retinal feeds running. Stacks was dozing, but when he heard Castheiser he jerked awake. The young man wore a now-familiar intense look. The older one nodded, but it was clear his attention was on his retinal feed. As Stacks made toward them, the young man’s gaze lost its lustre.

       ‘Excuse me,’ said Stacks, and when both men turned to him their retinal feeds died. ‘I couldn’t help overhearing you a moment ago. Could you tell me what Castheiser is?’

       The older man stirred. ‘What is it you want, sir?’

       ‘Castheiser,’ said Stacks. ‘He just said it to you. Do you know what it is?’

       ‘I didn’t hear that.’

       Stacks hesitated. ‘It is possible you weren’t listening. With the retinal feed and all.’

       The man bristled. ‘Who are you to tell me what I did or didn’t hear?’

       ‘We don’t want any trouble,’ said the younger man.

       Stacks shook his head. ‘I don’t intend to cause any.’

       ‘May I ask why you were eavesdropping?’ asked the older man.

       Stacks sighed. ‘I wasn’t. My eyes were closed. It was only because he mentioned Castheiser that I—.’

       The younger man interrupted him. ‘What is Castheiser?’

       ‘I don’t know,’ said Stacks. ‘That is my question to you.’

       The transRapid slowed. ‘Look,’ said the older man. ‘Whatever you heard, neither of us can help. We’d appreciate it if you left us alone.’

       Stacks swallowed. They thought either he was crazy or he was hustling. ‘Okay,’ he said. ‘Sorry to have bothered you.’ He backed off, resumed his seat. A couple of other passengers gave him sideways glances. The two men kept him in view until they reached their station, then disembarked. They were replaced by more suits who spoke about everything but the crisis.

       Stacks closed his ears to them all.

 

 

       

       Castheiser came to him again as he was drinking in a bar after the Artsutanov wind-up meeting, during which he’d officially been fired. Even as he left the parent company building, he’d received an alert from the Department of Labour informing him he had five days to find a job before he would be automatically assigned to an environmental clean-up crew.

       After three blacklights Stacks was numb to his plight. He was about to order another when he heard it. A single word snatched from the amorphous babble that flowed from one end of the bar to the other.

       Castheiser.

       His eyes searched the curated gloom for the source, but the bar was the kind of place where privacy came first. Black plastiglass concealed faces and bodies, turned the bar into a hundred exclusive cubicles. In his intoxication Stacks began to laugh, low at first and then more frantic, before dissolving into a coughing fit. A cross appeared on the face of his tender, indicating it would serve him no more alcohol.

       Perhaps, Stacks thought, he was losing it. Maybe his mind was scrabbling to fill the gaps left by the loss of the project into which he’d poured the best years of his life. The skylab had given him hope that a future could be salvaged for humanity. Now that was gone, brought down by a single errant entertainment satellite. And as the world crumbled a little more around him each day, his mind was desperately trying to string up another safety net for his psyche.

       How did one tell one was crazy? Didn’t the act of asking the question prove he was sane? Or was he too far gone to be able to make any such judgement?

       With his head thick and his body clumsy he paid his tab, stumbled out of the bar and walked home through streets that were too warm for March.

 

 

       

       Stacks’s next encounter with Castheiser was different.

       He’d been walking through the city without purpose for hours. He had just one day left before the Department of Work crewed him, but he couldn’t bring himself to scroll through his contacts in the hope of finding a lifeline. Instead of parking himself in front of the stolen console and browsing the DoW’s own meagre listings for a person of his qualifications, his legs had carried him out the pod door and onto the kinetic paving strips that criss-crossed the city.

       The longer he walked, the more astounded he became. The years he’d spent working on Artsutanov had blinded him to the changes happening all over. He barely recognised London.        Everything was new, sleek, spotless. To look at the place, it was almost impossible to imagine that global supply chains were on the brink of collapse, that Europe was groaning under the weight of climate migrants, that the world was succumbing to infernos and rising waters and drought. It was business as usual.

       In an attempt to find the city he remembered, he went south of the river to his old stomping ground of Tooting. Even here, though, something felt off. It took him several minutes to realise what it was.

       Efficiency ruled everything.

       Every window was of the same low-E, double-insulated design because that was the type that saved the most energy. Every newbuild wore the same generic cladding because that generic cladding required the fewest resources to produce. Every shuttle stop was two metres tall and four across. No frills, additions or enhancements. Nothing existed purely for the hell of it.        Beauty, spontaneity and creativity counted for nothing.

       It wasn’t until he reached Mitcham that Stacks finally encountered signs of the old life. Concrete next to red brick. All-in-one rubbish bins. Unkempt grass poking between non-kinetic paving slabs. The people moved slower here; time was still carbon, but it was worth less. Stacks fell in with them, his tired feet relieved by the new pace, and when he saw a bench with wooden slats he took a seat.

       Across the road was a chain-link fence, and beyond that a concrete wall. Sprayed on it in yellow paint was a single word in capital letters.

       CASTHEISER.

       Stacks lurched to his feet and followed the fence to its end, then doubled back to where the word was scrawled. He traced each letter with his finger. The markings were fresh. He stepped back, looked down the length of the wall, saw only bare concrete. He looked to the sky, a silent plea on his lips.

       When he felt a presence at his side, he turned to find a woman wearing too many clothes. She was smaller than him by a head, and her skin was grey. He took her for homeless.

       ‘Know what it means?’ she asked. Her voice was full and clear.

       ‘No,’ said Stacks.

       ‘I do.’

       He shifted so he was face to face with her. ‘If you’re joking, I’m not in the mood.’

       ‘It’s no joke.’

       ‘What do you know?’

       ‘You’ve heard people talk of it, too, haven’t you?’

       ‘Yes.’

       ‘This name is on the lips of the money men.’

       ‘What does it mean?’

       She nodded at the wall. ‘Can’t you see? Look carefully.’

       He did as she said, but saw nothing that hadn’t already occurred to him.

       ‘Tell me.’

       She laughed. ‘The name of Christ is in this word.’

       He looked again, saw she was right. But that didn’t mean anything. ‘So?’

       ‘Don’t you understand?’ she asked, her eyes bright. ‘When the money men speak of Christ without awareness, it can mean only one thing: He is coming. He has seen what we have done to this Earth and He will purge it of those who committed the crimes. Then life will begin again. A better life.’

       Stacks wanted to laugh, but his throat was tight. ‘You can’t be serious,’ he managed to say.

       ‘Why not? You look like a learned man. Do you fear the future?’

       ‘Of course.’

       ‘Why?’

       ‘You know why. Everyone knows why. The only truth in this world today is that we all lie to ourselves about how bad it is.’

       ‘Precisely.’

       ‘But that doesn’t mean Jesus Christ is coming to save us.’

       The woman shrugged. ‘You shall see.’

       She drifted away without another word. Stacks looked at the wall again. The letters jumped out at him. You’re a scientist, he told himself. You don’t believe in things like that. You’re not being rational. She’s just crazy.

       But later, back in his pod, he found he was still thinking about what the woman had said. When he closed his eyes, he saw yellow letters sprayed on concrete, and of them six glowed and rearranged themselves into a name that meant the Redeemer. He saw the word and he saw the world and he saw that they needed a miracle.

       And Stacks was afraid of what March twenty-first might bring.

 

 

       

       It started quietly. No fire and brimstone raining from the sky. No golden haze gilding London’s scraperscape. When Stacks peered out the window, he saw what he always saw: a city in perpetual motion. Roads full, buildings electrified, pedestrians marching. He alone, it seemed, sat unmoving.

       When his wall terminal flashed to inform him he was late for plastic collection detail, he switched it off. He’d done it two days in a row already; the work stretched his back, made his body hurt. His gov-issued tool, a long metal pole with a spike on the end, stood accusingly in the corner, but he ignored it, instead making himself a cup of ersatz using the last of the powder in the tin. He drank it at the window as he looked out at the world.

       Nothing.

       When his cup was empty, he took a shower, trimmed his beard, dressed in his sole clean suit and tidied the pod. With nothing left to take care of, he went to the stolen console and ran a search of the text-web. The news was full of headlines proclaiming doom and distraction. Catastrophic floods in the north, protests that had turned violent in Cornwall, a tiltrotor with three European parliament ministers gone down over the Ardennes. He checked another source. Rolling blackouts, far-right marches, speculation that the downed tiltrotor had been tampered with prior to take-off. He read and read, swiping and zooming and dismissing. No mention of anything that could be construed as the Second Coming.

       Stacks shook his head, smiled weakly. He didn’t know if he should be relieved or disappointed.

       Then, at the bottom of the page, one word in a box.

       Castheiser.

       With trembling fingers, Stacks touched the screen. It faded to black for a moment. Then there was a white woman with perfect teeth beaming at him. A video. It began to play automatically.

       ‘No time to listen?’ she asked through her smile. ‘We hear you. That’s why there’s Castheiser, the new voice of business.’

       Soft music played and an office environment appeared on screen.

       ‘Castheiser is an award-winning holistic software suite that filters out vocal chaff and crafts efficient responses,’ said the woman. ‘Designed for face-to-face and remote business interactions, Castheiser places you in microsleep while it conducts the conversation. Afterwards, you have all the pertinent information from the exchange at your fingertips. Less blah blah, more ta-da! As a subscription-based neural assistant, Castheiser is designed to piggyback on your existing implanted neuro-ID chip, so no additional tissue work is required.’

       A graph appeared.

       ‘A standard business conversation between two human beings lasts approximately six minutes and eight seconds. The equivalent conducted between two Castheiser suites takes just eighteen seconds. Preliminary studies have shown that managers who use Castheiser have improved their work rate by 37.3%, giving them more time for tasks they would otherwise put off. As more users take advantage of Castheiser, conversations will become even quicker thanks to the learning nature of the algorithm.’

       The woman reappeared on the screen, still beaming.

       ‘Welcome to the future of business discourse. Take control of the conversation.’

       The video ended and redirected to a website. In a daze, Stacks swiped through it. More videos about algorithms and data science and efficiency in business. A subscription page that could be accessed using the visual-web. An address of a headquarters in New York. Case studies and reports. A shiny logo of a C with the silhouette of a face inside it.

       Stacks swiped the site away and searched for Castheiser. The web was awash with it. Stories about how the new AI-assisted service had commandeered the chips of prominent entrepreneurs and business minds for periods of five to ten seconds to raise awareness of the company name before its launch. Thinkpieces on how brilliant the gambit was. Editorials about how ethically questionable it was. Guides on which subscription plan was best for specific personality types.        Proclamations about how the neural assistant would revolutionise the business world.

       Stacks read it all.

 

 

       

       By the time Stacks deactivated the stolen console, the day had faded. He retrieved the gov-issued plastic collection tool from its corner, and after he’d flipped the window toggle he pushed the tool into the crack and put his body weight against it until the window bent far enough inward that he could grab it with both hands and wrestle it to the ground. Cool clean air, non-filtered, non-recycled, rushed into the pod and Stacks took in a lungful of it. He leaned his head out into the night, closed his eyes, listened to the city speak to him in a voice that was strong even though it was dying.

       He clambered over the wrecked window and sat on the lip with his legs hanging in the void. Castheiser had done its job, he thought to himself. If only for the briefest time. Salvation made tangible when he’d needed it most. An illusion, just like his skylab, but an enchanting one all the same.

       Stacks looked up, past the curving branch from which his pod hung, to the stars. The glow of the city made them invisible, but he imagined he could see them anyway. A million unblinking eyes gazing down on him and everyone else, watching and waiting to see what their next move would be.

       He was only glad he no longer had to worry about it.