After that, for a while, none of us said anything.

The serving arm set down a tray at the next table, lifted it again, corrected the angle and set it down once more. On my display the grey line waited beneath the hesitating stroke, and under it the small, polite entry: 03:12. Account holder. Access granted.

I read it a third time, as though the words might rearrange themselves if I gave them the opportunity. They didn't. They had the particular stillness of a record, which does not care whether you believe it.

I tried to remember the night.

I remembered the window, the towers brightening, the cloud letting go of the light. I remembered switching off the display and the hesitating stroke staying with me a little longer than the light did. I remembered going to bed. After that there was nothing: not darkness, not a dream, simply nothing, the way there is nothing on the far side of a wall. I had never before had any reason to inspect that nothing. Every night of my life I had handed myself over to it and been handed back in the morning, and I had never once asked who was minding me in between.

Wheatley had. A disturbance a little after three.

I looked down at my hands on the table. They were my hands. The bank could identify them perfectly. The ink from the museum quill was still on my right forefinger, a grey smudge in the whorls, and I found myself examining it as though it were evidence against someone, and then realizing that it was.

Somewhere in me, a professional voice I had trained for eleven years began, quite calmly, to write the incident report. Subject accessed restricted legacy record at 03:12 using valid credentials. Subject states no recollection. Recommend suspension of privileges pending review. It was a good report. I had written dozens like it about other people. I had never once, writing them, considered that the subject might be telling the truth.

"Hey."

Lalu's hand was on my forearm. I hadn't seen him reach across.

"Do you walk in your sleep?" he said. It came out lighter than his face.

"No."

"How would you know?"

"Wheatley would know," I said, and heard how thin it sounded.

"Wheatley," said Lalu, raising his voice towards my pocket, "does your guv'nor walk in his sleep?"

"Not on my records, sir. He talks a bit. Mostly about quarterly reports."

"That's worse," said Lalu, and waited for me to laugh. I didn't. He took his hand back and, for once in his life, didn't fill the silence. He picked up his cold drink, looked at it, and put it down without drinking.

Sethu had not taken his eyes off me.

"Somebody used your credentials," he said quietly.

"Nobody can use my credentials." It came out too fast. I heard it, and went on anyway, because it was true and because I had spent eleven years making it true. "The token's bound to my biometrics. They're checked continuously against the device in my hand and the implant in my wrist. If anyone else tried, the system wouldn't grant access. It would lock the account and wake me. That's what the rule is for. I wrote the rule." I realized my palm was flat on the table, the way I held it in meetings when I wanted to be believed.

Then I heard whose sentence it was.

They couldn't. The chairman had said it yesterday, almost in those words, when I asked him what our systems would do if someone stole his credentials. I had not let him off. If they did, I had insisted, and pressed the hypothetical on him in front of the whole table, and rather enjoyed watching him reach for an answer. Then your department would have failed, he had said.

Now the hypothetical had walked into my own account at twelve minutes past three, and I was defending the door exactly as he had: by insisting that nobody could come through it. And my department, the one that would have failed, was me.

"Then the system says it was you," said Sethu, not unkindly.

"The system says it was my account." The distinction sounded smaller out loud than it had in my head.

"Is there a difference?" asked Lalu. He said it gently, which frightened me more than if he had said it as a joke.

It was the second time in a minute that the boardroom had come back for me. I had also asked the chairman whether perfect credentials would tell us who was using them, and he had said they would establish identity to the required standard. I had thought it the most revealing sentence of the meeting. Now the required standard had looked into three o'clock in the morning and found me there, and the only thing I could set against it was that I did not remember, which is exactly what a guilty man says.

I looked up and caught Sethu's eyes, and in them, for less than a second, something I recognized because I had felt it myself across a hundred interview tables: not suspicion exactly, but the small step back of a reasonable man recalculating. He had met me an hour ago. He did not know me. To him, I was a stranger whose own records said he had done something in the night and who now said he hadn't. If I had been in his chair, I would have stepped back too.

He saw that I had seen it. To his credit, he didn't pretend otherwise.

He set his cup down very carefully, as if it too might be evidence. "I'm sorry," he said. "I don't know you yet. I only know what the screen says."

"That's what everyone knows," I said. "That's my whole profession."

"I know him," said Lalu.

We both looked at him.

"I know him," he said again, to Sethu, quite flatly. "I've been stuck on a ship with him for months. I've watched him panic about fuel he had plenty of. I've watched him refuse to steal a sandwich from a pirate. Maybe his hand did open that file at three in the morning. I don't know, and neither does he. But I know it wasn't to cheat anybody. If he'd done something he was ashamed of, he'd have woken me up to tell me he was worried about it." He shrugged. "That's my verification. It isn't on any server."

It was a strange thing to hear from Lalu, of all people, who had spent a whole voyage turning his little dial and telling me that nothing counted unless it could be measured. I wanted to point that out. I found I couldn't trust my voice, so I drank some cold Atomo® instead.

"I could raise a ticket," I said eventually, rubbing at the ink on my finger. It only spread.

"Who would it go to?" asked Lalu.

"My department."

"Who runs your department?"

"I do."

"So you'd be asking yourself," said Lalu, recovering some of his old pleasure, "to investigate whether you did something you don't remember doing, using a system that says you did it."

"Put like that—"

"I can't think how else to put it."

Sethu drew the plan towards him and wrote on the notes side, under the list of things we hadn't seen: 3:12. Access granted. Who? After a moment he added a second line: Restricted from whom? He turned it so I could read it, and I understood that it was also an apology.

"Somebody restricted that record before your post existed," he said. "And somebody, or something, opened it last night with your name. Those might be one question or two. But neither will be answered at this table."

"No."

"So we do what we came to do." He tapped the scan, once, with the end of his stylus. "We read the page."

It was the right answer and I disliked it for being right. Every instinct I had been paid for told me to close the display, go straight to the bank and pull the logs until something in them confessed. But the logs would only say what they had already said, in the calm grey type that had never once in my career been wrong about anything it was able to see. It occurred to me, for the first time, that this was not the same as never being wrong.

I tried to put it aside. I told myself, in the voice I used on junior analysts, that the record would still be there in an hour, that a problem left alone for an hour is the same size when you come back to it. It didn't work. Three-twelve kept surfacing like a word on the tip of the tongue. My hand. My bed. A heart that had not hurried. Somewhere in the bank, a review was turning my night over without me, and by evening someone I had never met might know more about what I had done than I did.

I made myself look at the page instead. Brown at the edges, pale in the middle, the hesitating stroke. Whatever had happened at three o'clock had happened because of this page. Someone, or something, had reached for that record because of the same stroke I had shown the system that morning. The page and the night were one question, not two.

And I found, sitting there with cold coffee and the smear of ink on my finger, that I had decided something. I was going to find out who had written this, and who had opened that record with my name, whatever it cost me. The post, the clearance, the apartment with its well-trained kitchen: I could feel all of them, quite clearly, as things that could be taken away. I decided anyway.

I closed the panel with the access record and left the scan open.

In the café light the page looked different again, the dark lines bending across it like a field of grass leaning one way in a wind that had stopped centuries ago. At the bottom, the mark I had refused to call a signature, and above it the empty margin.

"Can I see what your system thinks it says?" asked Sethu.

"It doesn't think it says anything," I said. "It has candidates."

"Then show us the candidates," said Sethu.

I asked Wheatley for the transcription layer. A thin line of characters appeared beneath the first row of writing: the system's best attempt to assign each mark a symbol, so that something could at least be counted.

kG 173J z5^e5%2$ y3G5% t`Û yY5 wP$7i

Lalu leaned so close that his hat brim touched the screen.

"That looks like a strong password," he said. "The kind Madie keeps suggesting to me."

Sethu and I both looked at him.

"Madie?" said Sethu.

"My assistant."

"She?"

"I like having somebody to argue with."

I looked at him. He looked at me.

"You still use passwords, Lalu?"

"I'm a man of the past." He waved a hand at the screen. "And what are we here for? To bicker about my passwords? Come on, get on with your damn manuscript."

I sighed, and turned back to the screen.

"It isn't a password," I said. "It's a placeholder. The marks don't correspond to anything in the Linguafranca registry, so the system gives them arbitrary codes. It lets it look for repetition. Same mark, same code."

"And are there repetitions?" asked Lalu.

"Some. Not as many as there should be, if it were a simple cipher of a known language. Too many, if it were noise."

Lalu grunted, unimpressed by both possibilities.

"Show them the reconstruction, Wheatley," I said.

A second image opened beside the scan. The writing looked cleaner. Thin strokes had been joined, pale patches filled in, doubtful shapes separated into tidy groups. It looked, for the first time, like something a person might read.

"That helps," said Lalu, squinting.

"It makes it easier to look at," I said.

"Isn't that what you wanted?" Lalu asked.

"Some of the marks are additions," I said, and felt oddly as if I were confessing to something.

I asked Wheatley to show them. The added strokes turned grey. There were more than I remembered.

Sethu looked from one image to the other, and his finger stopped above a short grey line joining two marks.

"That little line makes these two into one thing."

"Yes."

"And without it, they could be separate?"

"Or parts of something else."

He drew his hand back.

"Then it hasn't only repaired the picture."

"No," I said. "It has chosen how the picture should be read."

"Several alternatives are retained, guv," said Wheatley.

"I know. Keep the original beside them."

I had asked for the clean version on the second day because the old one frustrated me, and its tidiness had been a relief. Watching Sethu hesitate over a line I had barely noticed, I was uneasy at how readily I had accepted the improvement. The system had not lied. It had simply filled the gaps with what it expected to find, and drawn its expectations in the same ink as the evidence.

Sethu studied the original line, then the page above it.

"Could it just be noise? Somebody making marks that look like writing?"

"It's possible," I said, because it was.

"No," said Lalu.

We both looked at him.

"Look at it," he said. "Not the codes. The page. The lines start at the same margin. They end before the edge, every time, even when the last word must have been squeezed. There's a gap between clumps. The clumps are different lengths. And the writer left that space at the bottom." He sat back. "Somebody wants to tell somebody something. You can see it the way you can see someone across a room trying to catch your eye."

I laughed. I couldn't help it.

"What?" Lalu demanded.

"Nothing. You've just proved something."

"I've proved I have eyes."

"You've proved you have more than eyes," I said. "Eyes see ink and paper. You're looking at ink and paper and seeing somebody behind it."

He opened his mouth to argue and was saved by the next table.

The boy from the signals room had turned up with his mother, and she had found a seat at last, at the table beside ours. She set down a tray from the serving hatch. The boy's hand shot out towards the nearest glass.

"Wait!"

It came out much louder than she meant it to. The boy froze with his fingers a breath from the glass. So did the three of us. Sethu's cup stopped halfway to his mouth; Lalu actually flinched.

The mother turned, colouring. "I'm so sorry," she said to us. "He had a cup of hot chocolate over himself last week."

"Not at all," said Sethu.

She moved the glass within the boy's reach, and he took it with great care and the dignity of someone who had never meant to grab anything.

Sethu watched him for a moment.

"He just heard more than a sound," he said.

"He heard his mother shout," said Lalu.

"He heard don't touch that, it's hot, remember last week, I'm frightened for you, wait for me. All in one word." Sethu turned his cup slowly. "None of that was in the sound. If you'd recorded it, you'd have a woman's voice going up. There's a whole lot that isn't in what your eyes see or your ears hear, and that's exactly the part that makes up the meaning."

"It's training," said Lalu, who had recovered from his flinch and clearly wished it forgotten. "He's been trained. Like a dog to a whistle. Say wait enough times with a hand on the cup and the hand stops by itself."

"That already assumes he's trainable," I said. "You can't train the lamp in the signals room. You can switch it on and off all day and it will never learn to wait."

"So which comes first?" said Sethu. "The training or something in him that can be trained? It's chicken and egg."

Lalu brightened at once.

"Now that," he said, "makes me hungry." He reached for the ordering pad. "Chicken. And egg. Both. Together."

"You can't have both together," said Sethu. "That's the whole point of the question."

"Watch me."

The serving arm brought them a few minutes later, a small grilled breast of something the menu swore was chicken and an egg done soft beside it. Lalu cut a piece of each, ate them in one mouthful, and closed his eyes.

"Delicious," he said. "Problem solved. They come together."

Sethu laughed and stole a piece of the egg. I ate a little of the chicken and found I was hungrier than I had realized. For a while nobody said anything, and the café went on around us, and the boy at the next table finished his drink and studied the empty glass as if it might still be hot.

It was while we were eating that it came to me, and I think to the others at about the same moment, because Sethu stopped chewing and looked at the page on my display.

Everything we had done that morning, every question we had asked of it, had taken one thing for granted. We had assumed the page was written for someone, or for something. That the marks were meant. That a page someone had bothered to sign must mean something to somebody.

None of us had started from the idea that it meant nothing. We couldn't have. Nobody begins there. It means nothing is not where you start with a signed page. It is the last thing you are entitled to say, and only after you have looked everywhere for its purpose and found none.

"We've been treating it as a letter," said Sethu quietly. "From the beginning."

"It's signed," said Lalu, with his mouth full. "What else would it be?"

I looked at the empty margin at the bottom of the page and did not answer.

It was Lalu who had the idea, and he had it in the way he had all his best ideas, sideways, while appearing to talk about something else.

"We keep saying for someone," he said. "Written for. Meant for. One thing leaning on another."

"Yes."

"Have you tried Lost in Translator?"

I stared at him.

"It's the thing the old university built," he said, as if I were being slow, which I was. "For dead languages. I saw a talk on it here, next to the sea-voyage one. The languages nobody can read, with no dictionary and hardly any examples and no spaces between the words. It doesn't try to translate them. It looks for relatives."

Sethu sat up. "Of course. If it's a lost language—"

"Then it had parents," said Lalu. "Languages don't fall out of the sky. They change in particular ways. A sound becomes a neighbouring sound, not a distant one. A p drifts to a b, not to a k. The machine maps all those likely drifts and goes looking for a family that this," he waved at the transcription line, "could have drifted from."

I knew of the system. Everyone in my profession did, in the vague way one knows of a museum's back rooms. I had never once thought of using it, because the bank's own engine had never failed to identify a language, and because it hadn't occurred to me, until Lalu repeated for someone, that the page might need a family rather than a translation.

"It's a licensed research tool," I said. "Globank has an institutional subscription. I can run it from here."

"Then run it," said Sethu.

I reached for the display, and stopped.

"Guv," said Wheatley, very quietly, "a word."

"Go on."

"Your identity token's still under review. Anything you run on the bank's subscription right now gets logged against an account that's being looked at. A lost-language engine, a restricted scan, a museum café—" He paused, and I could have sworn I heard him choosing tact. "It'll look like what it is, guv. And you won't be the one reading it."

He was right. I had written the review procedures myself. A flagged account that suddenly ran a classified asset through an outside research engine from a public café would escalate automatically. By evening it would be on the desk of someone who did not report to me.

"Then don't run it on the bank," said Lalu.

"It's the bank's document," I said.

"It's the bank's scan of somebody else's document. The somebody else, as far as anyone can tell, isn't complaining." He took out his own device, a battered thing with a cracked corner he refused to replace. "I've got a personal subscription. Museum members get it cheap. Madie can run it."

"Wheatley?" I said to my pocket.

"Policy is clear, guv. Bank material doesn't leave bank systems." A pause. "I'm obliged to say that. I've said it. It's in the log."

It was perfectly judged, as Wheatley always was. He had warned me, kept his own record clean and left the decision with me, all in three short sentences. Yesterday I would have called it tact. Now I caught myself wondering whose tact it was: mine, learned from me over eleven years, or the bank's, worn so smoothly into his voice that I had never once heard the seam. At the museum door he had told me just enough to stay calm. Here he had told me just enough to stay clean.

I looked at the page. Four days of the bank's best machinery had produced two empty fields and a list of rejected guesses. In a single morning, two men with no clearance and a cheap museum subscription had got further than my department, simply by asking different questions. If I went back to the office now and did everything correctly, I would arrive at the end of the week with nothing, and the chairman would put the collection in Sotheby's catalogue under a name nobody had earned, and the page would go wherever pages go once they have a price and no reader.

And somewhere in the legacy archive a record that matched its ink would stay restricted, and I would never know who had opened it with my hands.

"Encrypt it first," I heard myself say. "My key, not yours. It decrypts only inside the run and the result comes back to my device, not yours. Nothing's stored on your side."

Lalu held out his device as if I were offering him a cigarette. "You're a romantic."

"I'm a vice president of Cybersecurity breaking his own policy in a café."

"That's what I said."

It took me four minutes to wrap the scan in a layer of my own encryption that no subscription in NeoTerra could see through. My hands were steady. I noticed that because I had expected them not to be. Wheatley said nothing more. He did not argue; he recorded. A small amber light appeared beside his symbol on my screen and stayed there, which was his way of making a note.

Madie came on loud, flat and unmistakably from across the ocean, the voice of a woman who had been kept waiting at a counter since the last century.

"Yeah. What."

"I picked her voice off a setup menu," Lalu said, seeing my face. "Purely to annoy the menu."

Wheatley had begun the same way. When the bank assigned him, the screen had asked me to choose a voice, and I had picked, half in jest, a Cockney from an old film I loved, with a habit of calling me guv. That was all either of us had chosen. Everything else had grown.

Eleven years of my instructions, my moods and my silences had worn Wheatley into something no menu offered: a deference that knew precisely how far to go, a tact I did not remember teaching him, a way of saying right you are that could mean yes, or are you sure, or I'll be here when you've finished being foolish. Years of Lalu arguing with every answer she gave had, I could already hear, worn Madie into his exact opposite and his exact match: a woman who argued back, faster. Wheatley said guv and meant it. Madie said pal and meant the reverse.

Lalu called it personality. I had argued with him about that word across half the solar system. A personality, I said, has to be somebody's. Lalu and I had gone out on that voyage as ourselves and come back changed: the months, the asteroid, the pirates, each other, all of it had shaped us, and neither of us would have been the same without it. But there had been someone there to be shaped. The relations had worked on a person; they had not made one out of nothing. Nor had they left us untouched, like statues the weather slides off. A man was neither a knot of connections with nothing at the centre, nor a stone that nothing reached. He was both, someone and the history of his meetings.

Wheatley had the history. Eleven years of it, worn into habits no menu offered. What I could never settle was whether there was anyone at the centre for the history to belong to. Sometimes, listening to him, I wondered whether the tact and the patience I heard were his, or only mine, handed back to me so faithfully that I had stopped recognizing my own reflection. I was not sure which answer I would like less.

"Good morning to you too, Madie. Lost in Translator, please. One scan. My friend's encryption, his key. Don't keep anything."

"I never keep anything of yours, pal. Most of it ain't worth keeping." A pause. "Okay. Payload's in, locked tight. Running. Gonna take a while. Not that anybody asks how I feel about waiting."

Lalu put the device face up on the table between the three cups.

"She's very good," he said. "She just doesn't like me."

It took a long while. We ordered another round of Atomo®, which none of us drank. Sethu went to look at the navigation room for ten minutes and came back without having looked at anything. Lalu told a story about our hyperdrive voyage that I remembered differently, and I did not correct him, which he noticed, and which I think worried him more than the restricted record.

The progress mark on his screen crept round. Every so often it threw up a fragment: a sound correspondence tried and rejected, a candidate family considered and dismissed. Most of it was meaningless to me. Some of it looked uncomfortably like what my own system had produced in its first two days, before it had settled into producing nothing.

Then the rejections stopped.

A small tree began to draw itself across the screen. At the top, a dim node with no name, only a label: RECONSTRUCTED. Beneath it, branches. Madie read them out with the air of a woman reading a parking ticket aloud.

"Celtic. Gothic. Burgundian. Vandalic. Partial correspondence with each. Strongest weight towards an early Germanic grouping. Confidence low. Confidence not nothing."

Sethu breathed out.

"It's real," he said. "It's a language."

"It's related to languages," I said, but I could hear my voice failing to stay cautious. "That's what it's telling us. Whatever this is, it didn't come from nowhere. It sits somewhere in the family that gave us the old northern languages."

Sethu was looking at the scan rather than the tree.

"Did it use the grey strokes?"

Madie answered before I could. "In some runs. You want the ones without?"

"Please."

The tree trembled and redrew itself. Celtic thinned to a dotted line and vanished. Several of the most attractive links went with it. Gothic and Burgundian stayed, fainter but still joined to the dim node at the top.

"And the controls," I said. "Shuffle the groups and run them again. If a scrambled page matches just as well, we've learned nothing."

"I always run controls," said Madie, wounded. "You never ask about my controls." A pale second tree appeared beside the first: the same marks, jumbled. It was almost bare.

Lalu let out a long breath.

"The scrambled one's got nothing."

"Which means the real one has something." I moved between the two views: with the grey strokes, without them. The first was easier to like. The second was easier to defend. "Keep both, Wheatley. And the effect of leaving the additions out."

"Already in the history, guv. With the wrong answers."

Sethu turned his plan over and wrote under his two lists: Language — Germanic. He looked at it, struck through Language, and wrote relatives above it in smaller letters. Then he pushed it across so I could see.

The correction pleased me more than any summary Wheatley could have written.

"Gothic," said Lalu. "Burgundians. I like this author more and more."

"They're some of the oldest written languages of the north," I said. "Most of them died. Some of them survive only in a handful of inscriptions." I glanced back at the scan. "And Finsics put this paper and ink in the seventeenth century. A thousand years after those languages had gone quiet."

"So somebody in the seventeenth century," said Sethu, "wrote a page in something descended from languages that were already dead by then."

"Or invented one that looks descended," said Lalu.

"Why would anyone do that?" asked Sethu.

Lalu shrugged. "Why does anyone do anything? For fun. For a secret. For a girl."

Then, at the bottom right of the sparser tree, separate from the rest, a single small node began to blink in a different colour.

"What's that one?" I asked.

Madie sounded, for the first time, almost interested.

"Anomaly. Vowel harmony and some word-endings consistent with a Finnic pattern. Doesn't belong in a Germanic tree. Either a borrowing, an error, or somebody mixed their ingredients." A pause. "It survives without the grey strokes, before you ask. It's in the ink, not in the guesses. I've flagged it. You're welcome."

"Finnish?" said Sethu. "In a Gothic family?"

"It shouldn't be there," I said.

"Most interesting things shouldn't be there," said Lalu. "That's how you notice them."

I looked at the small, wrongly coloured node for a long time. A language with Germanic parents and a Finnish accent. It was the first thing about the page that felt less like a puzzle and more like a person: someone with a particular ear, a particular taste, a hand that hesitated on the way down and went on anyway. Someone who had built this out of pieces of older things, deliberately, and left room at the bottom of the page.

"Can it give us words?" Sethu asked.

"Not yet, honey," said Madie. "It's given you a family. Families don't tell you what anyone said at dinner. Feed it more text and it might."

"More text," said Lalu, looking at me.

"The rest of the collection is under the chairman's lock," I said.

"Then unlock it," said Lalu, as if it were a jar.

"It isn't that simple."

"It never is, with you. That's why it's always interesting." He picked up his device, thanked Madie with elaborate courtesy, and was told to stop being sarcastic. "We've got a family and a foreigner. That's more than you had at breakfast."

It was. I sat with the little tree glowing between our cups and felt, for the first time since the boardroom, something that was not anxiety. The page was not noise. It belonged to something. Whoever had written it had stood inside a long line of speakers, borrowing, bending, changing one sound into its neighbour, the way everyone who has ever spoken has done. They had not invented their words out of nothing. Nobody does. They had received them and passed them on, changed.

"It's getting late," said Sethu, though it wasn't. He was looking at me rather than the time. "You should go home and sleep."

"I should go to the bank," I said, without moving.

"You should go home," said Lalu, "and sleep, and tomorrow we'll come back here and you'll lecture us about whatever you've read all night instead of sleeping. And if you open any restricted files at three in the morning, try to remember it this time. I'd like the details."

On the terrace, while we waited for the pods, Sethu pressed his folded plan into my hand. "Keep it," he said. "You'll want the lists." Lalu said nothing at all, which was unlike him, and gripped my shoulder hard as my pod settled, and held on a moment longer than he needed to.

I took a pod home. The window offered me a programme and I refused it before it had finished asking.

The city moved past in its orderly streams. Somewhere below the cloud the old languages of the north had been spoken in halls and fields and boats by people who had never imagined us, and somewhere in that long chain of speakers a hand had taken those words and bent them into something new and written it down and signed it. I tried to picture the hand and kept seeing my own on the museum paper, the line going down, stalling, turning back.

My apartment door opened before I reached it. The lights came up to my preferred level. The kitchen asked whether I would like dinner. It had never seemed so eager to please.

"Not yet."

I sat at the table and opened the display, meaning to read about Gothic, about the dead languages of the north, about vowel harmony. Instead, I found I had opened my account status.

The amber light was still beside Wheatley's symbol. Above it, a line had changed.

IDENTITY REVIEW: CLOSED.

"Wheatley."

"Here, guv."

"When did that close?"

"About an hour ago, guv. While you were in the café."

"What was the finding?"

He read it to me in the bank's own words, without any accent at all.

"Review of access event 03:12. Credentials valid. Biometrics consistent. Behavioural profile consistent. Device consistent. Finding: activity consistent with account holder. No anomaly. Token restored."

I sat very still. Behind me the kitchen hummed quietly, keeping a dinner I had not asked for at exactly the temperature I liked.

The system had looked at what happened at twelve minutes past three, weighed every connection it had, and concluded, to the required standard, that it had been me.

It had done what the reconstruction did to the page. Where there was a gap, it had drawn in the stroke it expected, in the same ink as the evidence, and called the result consistent. There was no grey to show me where the additions were.

"Is that good news, guv?" Wheatley asked. "Only your stress markers have gone up, not down."

I didn't answer. Outside, the towers brightened as the sky gave up its colour, and below them the cloud held on to the last of the light, and somewhere beneath the cloud there was ground. For the first time in my life I wanted very badly to stand on it, somewhere no system could tell me who I had been.

I woke late, to the smell of coffee and the brief, bright certainty that the bank had cancelled me.

The room was full of daylight. Pods were already moving between the towers, and the hour beside my bed was well past the one at which Wheatley usually began telling me how little of the morning remained. He had said nothing. The bank paid for him, as it paid for most of the conveniences that kept me fit to work for it, and for a few seconds I lay still and wondered which of them would be switched off next.

"Wheatley?"

"Morning, guv."

"Why didn't you wake me?"

"Research outside the office. You cleared the calendar. No first appointment." A pause, carefully weighted. "And you had a restless night. Sleep settings logged a disturbance a little after three. I let you have the extra hour."

I didn't remember a disturbance. I remembered the chairman, the three days and the museum ticket, and my employment came back to me in that order. I got up before it could change its mind.

In the kitchen, breakfast stood beside the coffee. Wheatley read me the overnight analysis while I ate. The system had found what might be a repeated cluster of marks, then withdrawn the suggestion after correcting for uneven spacing. Nothing had been identified.

"Keep the rejected proposal."

"Already in the history, guv. I keep all the wrong answers."

"Good. They're the only ones we've got."

The museum lay across NeoTerra, in a district I usually passed over on my way to somewhere that paid. When I settled into the pod, its window offered me a morning programme chosen for my interests. Yesterday's interest in handwriting had produced an advertisement for a company that would preserve my voice for the people I loved.

A woman stood in a room full of sunlight. She turned towards someone outside the frame, smiled, and said a name I could not hear. The picture folded into a row of family recordings; a small hand chose hers, and she turned and smiled again. Nobody need lose the sound of a person, said the caption.

The next advertisement went further. Concord Living offered Connected Living: paired implants through which two people could share sensations, even memories. A man sat alone in an apartment and reached towards a hand in another room, and the hand reached back.

I could imagine the comfort of it. Letting someone feel what I had never managed to explain. I was less sure about the morning after. If you remembered my childhood from the inside, whose childhood would it be? If your thoughts came back through the same connection, how would I know where mine ended? The chairman's implant had failed by mixing his thoughts with other people's. Concord Living was selling the same failure as a feature.

The window asked whether I would like to begin a free recording.

"No."

The woman vanished and the city came back. A pod drew level with mine; its passenger was talking to his own window and never looked across. Then a tower took him away.

"Leave the window clear, Wheatley."

"Right you are."

The pod set me down on the arrival terrace built into the museum's upper floor. The building stood back from its neighbours, pale stone cut with deep windows, and behind the glass people were walking at a pace I had almost forgotten was available.

Inside, the air was cooler. A short queue had formed at a waist-high barrier, and at its head stood a service robot with a reader set into its chest. Visitors held up their admission codes, the lens blinked, the barrier opened.

I unfolded one panel of my display and brought up the ticket.

The lens blinked.

"Identity token under review," said the robot. "Admission suspended."

I had expected invalid code, the kind of failure that a better angle or a cleaner screen would fix. This was a different sentence. I had written the policy it came from.

"Review by whom?"

"Identity token under review. Please step aside."

"The ticket was issued last night. The payment cleared."

"The ticket is valid. The token presenting it is under review. Please step aside."

Behind me someone shifted a bag from one hand to the other. The barrier stayed shut with the perfect calm of a thing that has never had to wonder whether it is right.

"Wheatley," I said quietly, "what's flagged?"

"Can't see it from here, guv. It's a standard automated hold. Something on the account touched a sensitive record and the system's having a think." He hesitated. "It doesn't say what."

Head of Cybersecurity, I thought. Suspended at the door of a museum by a rule I had drafted for other people.

"You can steer through an asteroid field," said a voice behind me, "but they won't let you into a museum."

There was a small pause before museum, just long enough to let me know how much he was enjoying it.

I turned. Lalu stood three places back, hat tipped away from his forehead, the grin exactly where I had left it years ago. Beside him was a slighter man holding a folded visitor's plan as though he had read it twice.

For a moment I could only look at him. I had nearly called him the night before. I had not expected to find him here, watching me lose an argument with a door.

"Where did you come from?"

"Three places behind you. You were busy being suspicious." He stepped forward and laid his own pass against the reader. A list of guest places appeared on its little screen. He chose one and nodded at me. "He's with us. He's harmless. Mostly."

The robot asked me to accept a guest entry on my display. I accepted. The barrier considered the matter and opened.

"There," said Lalu. "No asteroid required."

"It took your pass and not my identity."

"Then today you're a guest. It's very restful. You should try it more often."

His companion followed us through.

"This is Sethu," Lalu said. "Sethu, this is the friend I told you about."

Sethu shook my hand. He had a careful, amused face, the face of a man who listened to an argument all the way to the end before deciding which side was wrong.

"How much did he tell you?" I asked.

"Enough to know which friend."

"Diplomatic," said Lalu. "Let's see how long it lasts."

Lalu looked from my face to the display still open in my hand.

"Another expedition?" he asked me.

"Research," I said.

"Ah. An expedition with a budget." Lalu clapped my shoulder. "And this time, when you decide to call it off, we can just take a pod home."

There it was, inside the first five minutes. I glanced at Sethu, who was studying his plan with great interest and no intention of rescuing me.

"Are you going to hold that against me forever?"

"Only when there's somebody new to tell. Come on. Nobody should be interrogated by a door before coffee." Lalu set off confidently down the left-hand corridor. Sethu touched his sleeve and pointed to the right, where a sign showed a small steaming cup. Lalu glanced up at it, adjusted his hat, and changed direction as if it had been his idea.

The coffee came from a hatch where a small mechanical arm set cups on a tray. The menu called it Atomo® and assured me that not a single coffee bean had been involved. It tasted enough like coffee to make the assurance a secondary matter.

Lalu and Sethu had met here, it turned out, at a talk on old sea voyages. Lalu had asked more questions than the speaker could answer and carried on asking them in the café afterwards, and Sethu had stayed to find out where the questions were going. Since then they had come back for other talks, other rooms. I received notices for the same talks. Wheatley sent me the summaries. I had kept up with all of it without once meeting anyone who had been there.

"Whose idea was today?" I asked.

"Mine." Sethu unfolded the plan and showed me a circled room: When People Wrote. "It's about how people composed documents themselves. The working pages. Drafts, crossings-out, words squeezed in above the line." He tapped a small photograph of a page crowded to its margins. "I can spend ten minutes asking my assistant to change a message. Warmer. Shorter. More like me. It gives me a new version every time. Here somebody had to find the words himself. I wanted to see how."

"And afterwards the navigation room," said Lalu, tapping another circle further down. "Old instruments. That was the deal."

"That was the deal," Sethu agreed, in the tone of a man who expected to be reminded of it.

I looked at the crowded page. Nobody I knew wrote anything. Once the assistants had begun composing our messages, reports and presentations, we had handed over the composing too. We read, approved and asked for changes. At Globank I gave Wheatley instructions and chose between his drafts, and he wrote them within the standards of Linguafranca®, the authority that maintained the common vocabulary and approved forms of public and business language. A report could move between institutions without anyone having to argue about its words again. It was a great convenience. I had never once asked what it cost.

"Linguafranca would never have let that page out," said Lalu, looking at the photograph. "Too many words nobody approved."

"It wasn't public," said Sethu.

Lalu shrugged. "Everything's public eventually. Ask our friend. He works for a bank."

I put down the cup. They had made a morning together long before I had thought of coming here, and for a little while it was pleasant just to be included in it. But Sethu's photograph lay between us, and the crossed-out lines in it were too close to my own problem to leave alone.

"Something turned up at the bank," I said.

Lalu raised an eyebrow. "Is this the confidential part?"

"Yes."

"Good. Those are the only parts worth hearing."

I told them about the lockers: the clearance crew in the lower levels, the bundle of handwritten sheets, the locker whose records had not survived. Finsics, the seventeenth-century date, the number on the last page of the report, and the chairman locking everything away. One scanned sheet sent to my department, and three days to put a name to it.

Lalu had begun by listening the way he listened to my work stories on the hyperdrive, waiting for the joke. When I reached the empty fields, LANGUAGE and AUTHOR, he put his cup down.

"Your system can't even tell you what language it is?"

"Not yet."

"Your system can tell me what I'm going to want for dinner next Thursday."

"Your dinner has more data."

"And the name? Satoshi?"

"It's in the recovery notes. I haven't seen the passage."

"So the most famous unverified name in financial history turns up on a page your bank can't verify." He leaned back. "Somebody up there has a sense of humour."

"Somebody up there has a valuation."

Sethu had been listening with his chin on his hand.

"Finsics tested some of the sheets," he said. "Did they test yours?"

I opened my mouth and found I didn't know.

"They sampled a handful," I said slowly. "The report doesn't list which. They assumed that sheets bundled together were written together."

"That's a reasonable assumption," said Sethu.

"It's what everyone assumes about a bundle," I said.

"It's what everyone assumes about a family," said Lalu, "until somebody does a test."

Sethu moved his cup off the plan before it could leave a ring.

"Even if the page is old," he said, "you'd still want to know whether it's a first version. Somebody could have copied something older. Or used paper that was left over."

"Yes."

"Then let's see how they did it." He stood and folded the plan along its old crease. "We came to look at people writing. Let's look before you show us anything. Otherwise we'll only see what you've already decided."

I put my hand back in my jacket and left the display where it was.

The handwriting gallery was quiet enough to hear our shoes. Old manuscripts lay in shallow cases under low light, and beside each case a screen let you enlarge any detail without touching the original. I spread two fingers on one, and a crossed-out sentence grew until I could see where the ink lay heavier: the writer had struck the line through twice, as if once had not been enough to make it untrue.

The catalogue named the writer, the owner and the route by which the page had reached the museum, with links to other letters in the same hand. Even here a name had not simply emerged from the shape of a stroke. Somebody had walked a long way round, through letters and owners and sales, to arrive at it.

Sethu bent over a case where a replacement word had been squeezed into the margin and hooked back into the line.

"That's what I wanted," he said. "The page shows the decision. We don't have to pretend it arrived finished."

"We still have to guess why the new word was better," said Lalu.

"Yes," said Sethu. "But now we know where the question is."

At a demonstration table, visitors could try a reproduction pen cut from a feather, with a pot of ink and a stack of erasable sheets. I picked it up, dipped it far too deep, and watched a black drop fall onto the paper before I had written anything.

Lalu made an appreciative noise. "An important early work."

I tried again with less ink. The point caught on the first downward stroke. I lifted it a fraction, felt it skid, pressed again and let it travel on; the line went down, stalled, turned back on itself, and then decided to continue. I lifted the pen and looked at what I had made.

I had spent four days with that shape. I had followed it on the boardroom glass and on my lap in the pod and on my kitchen table in the dark. Here it was, wet, on a sheet of museum paper, with my thumb beside it.

"That's your bad line," said Lalu, reading over my shoulder.

"Everyone's first line hesitates."

"Does it?"

"The point catches. You lift. You go on. It's the tool, not the hand." I put the pen down and found I had said it more firmly than it needed. "That's useful, actually. A thick mark could be a fresh dip. A gap could be someone stopping to reload. If I can sort out the accidents of the pen, I stop mistaking them for features of the script."

"Don't solve the whole document from one bad line," Lalu said.

"I'm trying to become slightly less wrong about one bad line."

"A modest ambition. Unusual for a vice president."

A smear of ink stayed on my finger. I rubbed at it, and it spread.

At the next case, a signature ran beneath several lines of neat, evenly spaced writing, and the hand above it was plainly not the hand of the signature. Sethu brought up the label: the letter had been written out by a clerk, and the sender had signed it.

"So the person who signed it didn't write it," I said.

"And if the signature had been added by somebody else?" said Lalu.

"Then we'd need to know whether they were entitled to," I said.

"Or whether they were copying it for an archive," said Sethu. "A copyist reproduces the signature too. It's part of the text he's copying."

I looked back at the letter. In the boardroom I had insisted that a signature didn't establish who composed a document. Here even the signing could be done on someone's behalf, or copied by someone who had never met either of them. A name at the bottom of a page was not a person. It was a pointer, and a pointer could be passed from hand to hand.

The next room was given over to public signs. Over the doorway, in small capitals, the curators had painted a single line:

A SIGN IS SOMETHING THAT STANDS FOR SOMETHING ELSE — TO SOMEONE.

Lalu read it aloud in the voice of a tour guide who has been doing this for thirty years and would like to stop. "To someone," he repeated. "They've thought of everything." He looked round the room. "Why do we even need signs now? Nobody wastes time making sense of signs any more. Things just tell you where to go."

"Is that why you went the wrong way to the café?" I said.

Sethu laughed out loud.

"That," said Lalu with dignity, "was a test of the signage."

Inside, the room was laid out like a game. Old signs hung on the walls behind dark glass, and in front of each stood a small panel with a button and a question: What did this mean? Press the button, give your answer aloud, and the glass lit up to show whether you were right.

In the middle of the floor, on a low table, ran a model road. Above it hung three lamps: red, amber and green. A label explained that traffic had once been governed by lights at junctions, and that drivers had been trusted to look at them, interpret them and act. Small vehicles approached the red lamp, stopped, and moved off when it turned green.

A small boy of five or six was standing at the model with one hand in his mother's. She had the patient look of someone on her third circuit of the room; he had the look of someone who had been promised the button and was beginning to doubt the promise.

"Why do the cars stop?" he asked her.

"Because the light says so."

He nodded, entirely satisfied, and went back to watching. It seemed to me the shortest complete explanation I had heard all week.

Lalu had gone straight to the first panel. Behind the glass hung three brass balls on an iron bracket, dull with age.

"Easy," he said, and pressed the button. "A juggler."

The glass lit up a polite red. A pawnbroker. Money lent against goods.

"A juggler of finances," said Lalu, without a pause. "I was speaking metaphorically."

"You were wrong," said Sethu.

"I was interpreting. Wrongly. It's different."

He moved on to the next panel: an enamel plate with a white zigzag climbing a blue ground.

"Now this I know," he said, and pressed the button with tremendous confidence. "Stairs."

The glass lit green. Stairs.

Lalu turned to us with his arms spread, a man vindicated before witnesses. "You see? Some of us can still read."

"It's a picture of stairs," said Sethu.

"And I read it." He regarded the zigzag with something close to affection. "Our fathers used to walk up and down these, you know. One step at a time. On their own legs."

"Up here in the skyscapes we'd need a week to walk anywhere," I said. "We take a pod to go two floors, up or down."

"Which is why nobody can read the sign any more," said Lalu. "They took away the stairs."

I watched him, and it struck me that in two guesses, one wrong and one insultingly easy, he had never once guessed that the thing meant nothing. Not once had he looked at the brass balls and said, that's three balls. He had gone past them, straight away and without being asked, looking for whatever they were there to tell him. He had simply looked in the wrong place.

By then Lalu had lost interest in the panels altogether and wandered back to the model road, where he leaned on the rail beside the boy, who eyed him with suspicion. Sethu was bent over a yellowed graph further along, the line on it climbing hour by hour up a column of temperatures, his lips moving as he worked it out.

I had stopped in front of a disc of red wax pressed with a crest. I didn't need the button. A seal: someone's mark, set on a letter to stand for the person who wasn't there to vouch for it. It was the obvious answer, and it gave me no pleasure. A seal was only a signature in another material. It pointed at a person, and the person was long gone, and still the wax went on pointing.

"Suppose," Lalu said, to nobody in particular, "a man came down from the moon and drove up to that junction. Red light. Does he stop?"

"He can't," said Sethu, without looking up from his graph. "He doesn't know the arrangement."

"So where's the meaning? It's the same lamp. Lit exactly the same for him as for us." Lalu shrugged. "It's in what the crowd has agreed to do. Change the crowd and red means party."

"And this morning," said Sethu, glancing at me, "red at the museum door meant suspect."

I said nothing for a moment. I was thinking of Lalu at the brass balls.

"Your moon man wouldn't stop," I said. "But he wouldn't think it was nothing, either. Tell him it's a signal and he'd start looking for what it wanted from him, the way you did with the pawnbroker. You didn't know the code. You still knew there was one."

"I knew there was a juggler."

"You knew the balls were there to say something. Nobody had to agree on that part."

He looked at the lamp for a while. So did the boy. Then Lalu straightened up and said, "I need to sit down before someone makes me agree with you," and went towards a bench by the door.

Sethu and I followed. The curators had painted the same line above the door on this side too, for visitors on their way out. To someone. It occurred to me that they might have put the important part last.

"Here's my question," Sethu said, when we sat down. "That letter in the gallery, the one the clerk wrote out and the sender only signed. There the signature pointed at the sender. Fine. We know who he was, because the museum walked a long way round to find him. On your page, the signature points at somebody too. That's what signatures do."

"Yes."

"So what happens when you follow it and there's nobody there?"

I didn't answer at once. In the boardroom the chairman had asked what made a human real, and I had not been able to tell him. Here was the same question in a smaller coat. A sign points beyond itself. A signature points at a person. And at the bottom of the Satoshi page there was a pointer with nothing at its far end, or nothing that any system we owned could reach.

"Then either it's a sign that points at nothing," I said, "which is a strange thing to sign. Or it points at someone we can't reach from where we're standing."

"Or," said Lalu, "it's a pretty squiggle and you're very tired."

"That too," I said.

At the junction, the boy had found a way to make the little cars stop halfway across by pressing the button at exactly the wrong moment, and was doing it again with deep satisfaction. His mother said his name, then said it again with the second syllable longer. He lingered with one finger still on the button while she gathered her bag, looked round the room for somewhere to sit and found nowhere, and finally took his hand. He went with her backwards, watching the cars until the doorway took them.

Lalu stretched. "My brain wants coffee."

"Your brain always wants coffee," said Sethu, already folding the plan.

"Then it's a reliable brain."

They were for going back to the café and turning it all over there, and I agreed because it was easier than saying anything else. I had a great deal to think about. On the way out I looked back once. The room was empty now, and the lamps above the little road went on changing, red to green to red, the cars stopping and starting obediently for nobody. Without anyone there to read it, the light was only a coloured glow over a toy road. And yet every sign in that room, the brass balls, the little enamel staircase, the wax, had been made by someone who expected someone else to come along and look past it.

I had come in that morning believing the hard part of my job was the reading. I was no longer sure I knew who was at either end.

Back in the café, I ordered another coffee. Lalu chose something cold. Sethu asked for water and waited while the serving arm found a clean glass. The window beside our table had started advertising the museum's own preservation service: a handwritten note unfolding beside a child's photograph. I could not read the note from where I sat. It reminded me of the woman in the pod window turning towards somebody I couldn't see.

"So," said Lalu, setting down his glass. "We've seen how they used to write things and sign them for somebody to read and understand. Are you going to show us your classified file, or do we have to guess at it like the brass balls?"

Sethu turned his plan over to the blank side meant for notes and took a stylus from beside the ordering pad.

"Before you show us," he said, "tell us what you've got. And what you haven't."

"One scan. The Finsics report. The report's conclusions."

He wrote them down.

"And haven't?"

"The original sheet. The other sheets. The passage where the name comes from. Which sheets Finsics actually tested. Whatever's left of the locker record."

He wrote those too, leaving a space between the two lists.

"Put the rejected readings somewhere," said Lalu. "The ones your machine threw away."

"Wheatley keeps them."

"Then let him. You came here to find what your tools missed. Don't throw out what they found."

I unfolded the display flat on the table. Opened out, the screen was wide enough for three heads to bend over a page, and Sethu moved his water clear of the edge.

"You don't have to spend your morning on this," I said.

Sethu looked at his two lists. "I came to look at unfinished work."

Lalu glanced at the navigation room circled on the plan, sighed theatrically, and pulled his chair in anyway.

"You owe me those instruments," he said. "Show us the page."

I asked Wheatley for the scan.

It came up brown at the edges and pale at the centre, the writing bending across it in its dark, uneven lines. Lalu leaned in. Sethu said nothing for a long moment, then put one finger, not quite touching the screen, under the hesitating downstroke.

"That one," he said.

I didn't look at the ink still on my own finger. I didn't need to.

"The system says there's no match anywhere," I said. "Every archive we license. Nothing."

"Every archive outside the bank," said Sethu. "What about inside?"

I had not thought to ask. In four days I had searched the world and never once searched the building I worked in.

"Wheatley," I said. "Isolate that downstroke. The one Sethu's pointing at. Compare it against everything Globank holds. Every scanned contract, every legacy signature card, every specimen in our own vaults."

"Internal records, guv? That's a wide net."

"Then cast it wide."

"Right you are."

A thin outline settled around the stroke on the screen, and a progress bar appeared beneath the page. It crossed the screen faster than I expected.

EXTERNAL RECORDS: NO MATCH.

INTERNAL RECORDS: 1 RESULT.

And under it, in the bank's calm grey type:

ACCESS RESTRICTED. YOUR AUTHORIZATION LEVEL IS INSUFFICIENT.

Lalu read it aloud, slowly, as if it might be a joke he was missing.

"Your own bank won't let you see?"

"There are perhaps four people in Globank whose authorization is higher than mine." I heard my voice stay level and was grateful to it. "It's an archive permission. Old records get locked and forgotten. Wheatley, what is it?"

"Can't see it either, guv. It's in the legacy archive. The restriction's older than the current system." A pause. "Older than your post."

"Who set it?"

"The field's blank, guv."

Blank, like LANGUAGE. Like AUTHOR. I told myself that blank fields were the most ordinary thing in the world. I had spent four days telling myself so.

"There's something else," said Wheatley. For once he sounded as though he would rather not. "The record keeps an access log."

"Records do."

"It's been opened, guv."

"When?" I said, and realized I was hoping for a date long ago: some clerk, decades dead, looking for a signature card on a slow afternoon.

"Last night."

A small figure appeared at the edge of my display, where Wheatley kept the readings the bank liked him to keep. I had never paid it any attention. It was a number, softly green. Heart rate 72. Normal. It had been normal all my life.

"Last night when?"

"Three-twelve this morning, guv."

The green number jumped.

I did the arithmetic without wanting to. A disturbance a little after three. The extra hour of sleep Wheatley had so kindly allowed me. The robot at the door: identity token under review. And Wheatley's careful phrase at the barrier: something on the account touched a sensitive record. The museum had not refused a ticket; it had refused an account, flagged for what it had done while I slept. Wheatley had said, at the barrier, that the hold didn't say what. I had believed him, the way I believed everything the system told me, without ever deciding to. Now, for the first time in eleven years, I wondered whether he had known.

"From where?" I said. I was working now, the way I worked at the bank, and it steadied me. "Which device? If someone cloned a token, the location will be wrong. They'll have come in through a relay, or a—"

"Your apartment, guv. Your bedside device. It was on charge."

"Then the device was compromised. Somebody reached it remotely and—"

"Biometric session was live, guv. Wrist implant in contact, pulse present, pattern matched. The device wasn't alone." He hesitated, and I had the absurd impression that he was sorry. "Would you like the pulse at the time?"

I didn't want it. "Yes."

"Sixty-eight, guv. Resting. Very calm."

Whoever had opened that record at twelve minutes past three had done it with my hand, my pulse, my bed, and a heart that had not hurried at all.

Mine was hurrying now. At the edge of the display the number had turned amber and would not settle.

Sethu had stopped looking at the screen. He was looking at the small amber number, and then, carefully, at me.

"Opened by whom, Wheatley?" I said. I knew. I asked anyway, the way one presses on a bruise to be sure of it.

There was a pause in which I could have sworn he was choosing his words, though I knew perfectly well that he had none to choose.

"By you, guv. Your account. Your credentials. Access granted."

The reading broke into an erratic stutter, climbing and catching and climbing again.

"Your heart rate's up, guv," said Wheatley gently. "Would you like me to bring it down?"

"No."

He said nothing about the record itself. Not that it was wrong, not that it was right. Only the pulse, which he could fix. At the barrier, too, he had told me no more than I needed to stay calm.

The café went on around us: the hiss of the hatch, the mechanical arm setting down cups, a family on the terrace gathering their bags. Every system I trusted agreed about what had happened at three o'clock that morning. My credentials agreed. My device agreed. My own pulse agreed, faithfully recorded, steady as a sleeper's. There was nothing on the whole of my side of the table except the fact that I did not remember, and I had spent my career teaching machines to disregard exactly that.

Then Lalu spoke, quietly, without looking at the screen at all.

"Whatever happened at three o'clock," he said, "I trust you to do the right thing."

The right thing according to whom? As far as the bank was concerned, something had already gone wrong. A restricted record had been opened. A protocol had been broken. And the hand that broke it was, by every measure we had, mine.

Still, I had to look down at the table for a moment until I could trust my face. Wheatley had offered to steady my heart rate. Lalu had steadied something else. I could not have said what, but it soothed me in a place no reading reached.

The little number at the edge of the display did not care. It went on stuttering. I looked at the hesitating stroke, and at the smear of ink on my finger beside it, and understood that for the first time in my professional life I could not verify who I had been at three o'clock in the morning.

The chairman wanted a name, and he wanted it before Sotheby's printed their catalogue.

Behind him, the boardroom windows opened onto NeoTerra. Most of the city I knew stood well above the ground: offices, apartments and gardens gathered into towers whose upper levels we called the skyscapes. Between them, zip pods moved in orderly streams, carrying us from the departure bay of one building to the arrival bay of another, so that nobody of consequence ever had a reason to go down to the streets. Far below, a bank of cloud concealed whatever was left of them.

On the glass, which also served as the boardroom's shared screen, the scan of a sheet of paper hung above the city. Its edges were brown, its centre pale, and the writing bent across it in dark, uneven lines. A zip pod crossed behind the image just where the page ended in a signature, and for a moment the signature seemed to be travelling somewhere.

"Well?"

I looked away from the page.

Around the oval table sat the other vice presidents, each in the black suit that the bank's dress code described as timeless. Seen together, they had always reminded me of bats hung along a branch: patient, folded, waiting for dark. An old philosopher had once asked what it was like to be a bat and concluded that we could never know. Looking at my colleagues, I suspected the bats didn't know either.

"I haven't established the author," I said.

The chairman glanced at the time display in the table.

"You have had the document for four days."

"A fragment of the collection."

"You have had the report."

"The report dates the paper. It doesn't tell us who wrote on it."

He touched a control set into the glass of the table, and the page on the windows enlarged until its margins disappeared. For a moment the writing seemed almost familiar. One downward stroke hesitated before turning back on itself, as though the hand had changed its mind halfway down and then decided to go on anyway. I followed it with my eyes, trying to imagine the wrist that had made it. Then the display sharpened, filled the room with the grain of the ink, and the impression was gone.

"What," the chairman asked, "has our verification system actually verified?"

It was a fair question. I disliked him most when he asked those.

"It has authenticated the scans we received. It has confirmed that our copies haven't been altered since acquisition. Beyond that, everything is preliminary."

"And the signature?"

"Requires a reference sample."

"Then find one."

"We don't know whose sample to find."

Across the table, the head of Marketing lowered his eyes. I could see him deciding whether this counted as humour.

The chairman remained perfectly still. Since the removal of his neural implant, he had developed the habit of listening with his whole face, as though he could make up for the lost chip by bringing more flesh to bear on the problem. The implant had been sold to him as a way of commanding his systems by thought alone. It had been removed after it failed to distinguish his thoughts from those of the people around him, and the lawsuit against Musky Inc. was now in its third year. The rumour among the vice presidents was that he had needed the implant in the first place to find out what he was thinking.

For several weeks while he wore it, I had made a point of thinking generous things in his presence. It had been exhausting. Blimey, it had been exhausting.

The head of Financial Security cleared his throat. His department owned the problem until it had become mine, and he wished everyone to remember the order of events.

"The collection was recovered from a legacy locker," he said. "There's an accession record. Finsics found paper and ink consistent with the seventeenth century. Linen rag, iron-gall ink, period watermark. The valuation is based on—"

"The valuation is conditional," I said.

His folded hands tightened.

"We all understand that."

The chairman looked at him, then at me.

"Do we?"

The facts, such as they were, could be told in a minute. Staff clearing out very old lockers in the bank's lower levels had found a collection of handwritten manuscripts: dozens of sheets, bundled, unlabelled, in a locker whose records had not survived the bank's last three migrations. Nobody had written by hand for generations, and the discovery had passed quickly upwards, from the clearance crew to Finsics, from Finsics to experts willing to put a price on it, and from them to the chairman, who had taken one look at the price and locked the entire collection away under his own authority.

Finsics had sampled a handful of sheets and found them old. They had reasonably assumed that sheets bundled together had been written together. Their report said seventeenth century on its first page and a number with a great many zeroes on its last, and between those two pages lay a good deal of chemistry that no one at this table had read.

My department had been sent the report and a single scanned sheet, and asked to confirm what everybody already wished to be true.

Somewhere in the recovery notes, someone had recorded the word Satoshi. I had not been shown the passage. It had become a convenient label for a collection nobody could explain, and then something more than a label. A bank can hardly hear Satoshi without thinking of Satoshi Nakamoto, the vanished name behind Bitcoin, the most famous unverified identity in financial history. A seventeenth-century date made the association absurd, since the paper would predate Bitcoin by centuries, but around this table absurdity had become one more reason to call the manuscript extraordinary.

By the time the scan reached me, the Satoshi Document had acquired the authority of a title. A bundle of old pages had become one object with one origin and a price large enough to make questions about either seem disloyal.

"The language hasn't been identified," I said.

The chairman's mouth moved without producing a word. I went on before it could.

"Every morning the system returns more on the fragment. It separates the strokes, estimates the gaps, proposes groupings, rejects them and tries again. It can measure features of this writing I would never notice. But the fields headed LANGUAGE and AUTHOR are still empty. The Linguafranca registry has no entry for the script."

"Our systems contain the linguistic record."

"The record available to them."

That small qualification made Financial Security look up.

"Are you suggesting an archive failure?"

"I'm suggesting we don't yet know what we're looking at. It could be an unfamiliar script, a cipher, a constructed language, or damage to the sample. We haven't eliminated any of them."

The chairman turned to the page and studied it for several seconds, perhaps hoping that an executive decision could make it legible.

Then Marketing smiled.

"Should we start writing again?"

Nobody answered. He had meant it as a joke and was now watching it become an item for discussion.

The chairman pointed at the signature.

"Somebody signed that."

"Apparently."

"You can see the signature."

"I can see a mark where a signature would normally be."

"What else would it be?"

"That is what we have to find out."

He leaned back. His chair adjusted to him with a soft mechanical sigh.

"I asked you to verify an identity," he said, "and you are telling me we need to discover what a signature is."

I could have stopped there. I could have promised a further report, retreated to my office and spent the afternoon turning ignorance into charts. I had done it often enough to know exactly how long it took.

Instead I looked at my own name, illuminated on the glass beside my seat.

When I entered the building each morning, the bank recognized me before the doors opened. My office knew the temperature I preferred. The conference system had assigned my place, logged my presence and attached my words to the correct account. Every precaution had been taken to ensure that the person sitting in this chair was entitled to sit in it.

Entitlement was what we were good at.

"Mr Chairman," I said, "what would our systems need in order to recognize you?"

He stared at me.

"My credentials."

"And if someone stole them?"

"They couldn't."

"If they did."

"Then your department would have failed."

A faint smile appeared on the face of Financial Security.

"Suppose the credentials worked perfectly," I said. "The transactions were authorized, the biometrics passed, the history was consistent. Would that tell us who was using them?"

"It would establish identity to the required standard."

"The required standard for what?"

"For conducting business."

There it was: an answer so reasonable that I had spent most of my career inside it.

I rested my palms on the table.

"Our system verifies connections," I said. "This account belongs to these records; these records authorize these actions. It does that extremely well. It can tell me whether a thing fits everything else we hold. What it can't do is step outside everything we hold and tell me whether the whole arrangement is true. And here is a page that arrived with no connections at all. No custody chain, no metadata, no reference identity. Confirming that our copy is genuine won't attach it to an author."

"Nobody is suggesting that," said Financial Security.

"The valuation is. It treats the name on the collection as if it told us something about who wrote it."

"The name is provisional."

"Then the price needs to remember that."

The chairman lifted a finger, and we both stopped.

Beneath his hand, the table displayed the anticipated auction range. It was an impressive number. I understood why he preferred looking at it.

"What are you asking for?"

"Time to study the writing in its historical context. Access to the original sheets. Comparable documents. Whatever survives of the locker record."

"You have the forensic report."

"I also need to understand it."

He considered this with the expression of a man who had just discovered that comprehension was an additional expense.

"Can a human do what the system cannot?"

The question ought to have pleased me. Instead it made me careful.

"A human may notice a different kind of connection."

"Such as?"

"Why somebody chose to write at all. What the page was for. Who they expected to read it."

"The system can make those inferences."

"Yes. Someone still has to judge whether they're good ones."

I heard the insistence in my own voice. Part of me had wanted to say that only a human being can understand another human being's work. It was a satisfying sentence. Lalu, my old travelling companion, would have laughed at it, and then asked how I knew the writer was human.

The chairman saved him the trouble.

"You keep speaking as if there must be a human being behind this," he said. "What if the author was a replicant?"

"We haven't established that either."

"Would the writing be less authentic?"

"No."

"Less valuable?"

"That's a question for Marketing."

Marketing looked wounded. The chairman ignored him.

"Then what is this distinction you're trying to protect? What makes a human real?"

The room seemed quieter after he asked it.

I looked at the hands around the table. One vice president was turning a ring on his finger. Another had laid his palms flat beside his display. Financial Security's fingers were still interlaced. I knew their appointments, their responsibilities and their risk profiles. With a suitable request, I could obtain years of their transactions. I could have told the chairman a great deal about every person in the room, and none of it would have answered him.

He was watching me fail to answer.

"I can't settle that in this meeting," I said.

"Then settle the document."

He closed the valuation display.

"Three working days. Sotheby's close their catalogue at the end of the week, and I intend this collection to be in it. Bring me a recommendation I can defend. If you need to conduct research outside the office, conduct it." He looked at me for a moment longer than was comfortable. "Report to me directly."

The others began gathering their devices. I folded my data display into a palm-sized rectangle and slipped it into my jacket; opened out, its flexible screen was large enough to read a page. One by one, the names around the table went dark.

Financial Security paused beside my chair on his way out.

"Keep your questions within the assignment," he said. His tone was almost kind. "Authenticate the sheets. Don't audit the century."

After he had gone, I looked once more at the scan. The display was already fading. The last strokes vanished before the first, and the page went blank from the bottom upwards, until only the hesitating downstroke remained, and then not even that.

My pod recognized me at the departure bay.

"Home?"

"Yes."

The door sealed and Globank withdrew behind the glass. I loosened my collar. The pod slid into a stream of traffic so smoothly that I noticed we were moving only when the neighbouring tower began to slide past.

At this height NeoTerra appeared to have solved most of the difficulties of being alive. The lanes curved between buildings without hesitation. Windows adjusted themselves to the sun. Gardens occupied terraces from which no soil could ever fall upon an important person.

"Guv?"

Wheatley, the assistant the bank provided with my position, spoke through the cabin speaker. He travelled with my account, and my account went wherever I did: office, pod, apartment and, on bad nights, into my dreams by way of the sleep settings.

"Go on."

"I can prepare an executive summary of the unresolved authentication issues for the chairman."

"Tomorrow."

"Right you are. A shorter one for this evening, then?"

"No."

A pause. Wheatley could accept a refusal with far more patience than I could.

"Your stress markers are up, guv."

"I've been in a meeting."

"I've allowed for that."

"Allow for it again."

"Certainly."

A small green symbol appeared beside the speaker: some measure of my condition was improving. I felt no corresponding improvement in myself.

I unfolded the display across my lap and reopened the scan. In the dim cabin the page looked smaller than it had above the city. I enlarged it only enough to see the margins. The writer had left a generous space below the last line, more than the page required. A careless luxury, perhaps. Or room for an answer.

The thought was mine. The page gave me no reason to prefer it.

"What do you make of that?" I asked.

"Please specify the feature."

"The empty space at the bottom."

"The lower margin measures approximately—"

"Never mind."

I closed the scan and immediately opened it again.

"What would you do if none of your proposed readings was right?"

"Generate further candidates."

"And if those were wrong?"

"Revise the search."

"What would make you stop?"

"An instruction from you, guv."

I almost laughed. The answer was accurate and difficult to live with. Lalu would have said that my discomfort proved a great deal about me and very little about Wheatley.

I had got into the habit of arguing with Lalu when he wasn't there. It let me choose his questions and answer them to my satisfaction. In person he was far less obliging.

Dinner was waiting when I arrived. The kitchen unit had warmed and plated something suited to my recorded preferences, and I ate it standing at the window, tasting enough to confirm that the settings were correct.

Beyond the glass the towers brightened as the sky lost its colour. A few windows caught the sunset directly; others borrowed it from the buildings opposite. Below them, the cloud held its dim light a little longer, then let it go.

I had once enjoyed this view without needing it to mean anything. Now I noticed how rarely anything in my life required me to stand still. Food arrived. Transport arrived. Information arrived before I had finished asking for it. The world had become exceptionally good at anticipating my next requirement, and I had become exceptionally good at having the requirements it anticipated.

"Shall I bring the lights up, guv?"

"Leave them."

"It's getting dark."

"I can see that."

I spread the display flat on the table and opened the scan once more. In the reduced light the discolouration of the paper was easier to read. Along one edge there was a darker patch that might have come from handling. I imagined a thumb resting there, long ago, while the other hand wrote.

There was no sound basis for the image. Still, I found myself looking at my own thumb. It had no distinguishing mark. The bank could identify it perfectly.

I brought up Lalu's contact.

His photograph was years old. He had refused every replacement the system suggested, on the grounds that they made him look trustworthy. We had been friends long before I became a vice president. At the launch pad for our hyperdrive journey he had turned up in a leather jacket, sunglasses and a hat, carrying a bag that turned out to contain a reclining chair. I had spent the night before worrying about the ship. He had spent it arranging to be comfortable in it.

The recliner's armrest had carried a dial labelled WORLD VIEW SETTINGS. Lalu would turn it and explain to me why what I called a fact was only a perspective, or why a theory mattered chiefly for what it let us do. I spent much of that voyage objecting. He spent much of it enjoying my objections. He had also kept the ship steady when we were caught circling an asteroid, and later, when pirates left us trapped aboard a Thark vessel, we had got each other out. The recliner stayed behind. Whatever we disagreed about, I trusted him with my life, which was more than I could say for most of the things I trusted with my identity.

It had been my decision to end that voyage early, before we reached the place he had dreamed of all his life. He had said he didn't mind. I had believed him the way one believes a well-formatted report.

If I called him now with a mysterious manuscript, I knew his first question would be whether this expedition, too, would be cancelled at the first inconvenience.

I closed the contact.

On the table, the unknown writer had committed a few lines to a page and left them there.

Perhaps I was making too much of paper. There had been forged signatures, anonymous threats and beautifully written lies long before anyone built a digital archive. Age could not make this page honest, and an irregular stroke could not prove that the hand behind it had belonged to someone with an inner life. Still, for four days I had been trying to fill a field in a report. Now, without quite deciding to, I wanted to know what had been entrusted to the writing, and to whom.

"Wheatley."

"Here, guv."

"The Museum of History. The manuscript galleries."

"Virtual visit?"

"I want to go there."

"Tomorrow, then. Your calendar has—"

"The chairman authorized research outside the office. Clear the next two days."

"Done. Shall I plan you a route through the exhibits?"

"Just the ticket."

The confirmation appeared: my name accepted, my account charged, my visit entered in the appropriate record.

I left it on the screen and turned to the window. The last light had gone from the cloud. Somewhere beneath it there was ground, and somewhere in that ground the city had its foundations. From where I stood, I could see neither.

I switched off the display. The hesitating stroke stayed with me a little longer than the light did.