The last Shanghai trip was to close out the paper records.
Before she left, the archive called: for the closing day, would she like a small ceremony, two media outlets, an unveiling of the cabinet? She said no ceremony; let the numbers go into the account. The archive asked about a plaque, then. She said no plaque. Hang a plaque, and the people who come after will only ever look at the plaque. A few seconds of silence on the line, then: All right. We'll print an extra copy of the summary page.
The side-light slot came at the end of October: three days, five cells. Light raked across the paper from the lower side, and the bled ink stood up in it, like a handprint held down underwater. Side light was the archive's old conservator's trick; he'd built the lamp frame from a scrapped microscope stand, the angle tuned with a coin slipped under one foot. She verified from the back of the paper with her fingertips, cell by cell. On the verso you can feel the groove the pen nib pressed—grooves are more honest than ink. Ink bleeds; grooves don't.
Four of the five resolved: two 6s, a 4, a 3. All the years were on record. The last cell she examined twice, the light moved through three angles, one more coin under the frame—and the digit only half came out, the strokes broken off at the bottom. She annotated beside it: half value, 1977. The archive asked whether a half value counted. She said it counted: enter it as a half value, state it plainly in the notes column. Numbers in the account don't fear being small; they fear being unexplainable.
Three doubtful cells remained. The archive brought the originals out; three sheets lay on the felt. Two cells everyone took turns at—under the loupe, only pooled ink, no nib grooves. The finding went into the record: ink blot, not a digit; left blank. Lu Weiming looked at those two and said: What's kept blank is also a number.
The third cell was from 1972. She had looked at it once six years ago, once four years ago, and put it back both times. Six years ago she thought there was a digit in it; four years ago she thought there wasn't. This time she lifted the sheet toward the window, no lamp. Daylight came through the back of the paper; in the pooled ink stood a vertical, and at the top of the vertical, a small hook. She matched the rows above and below on that year's page; the gap between them was exactly a 7. She entered it.
Entered, she signed the time in the register. The entry from six years ago was there, the one from four years too—three signatures in a row, same cell, same question, asked over six years. The young woman behind the counter said: This cell's file runs three pages thicker than the others. She said: Those three pages are part of it too.
The summary fell onto the intake form: fourteen thousand seven hundred forty-one numbers. The promise, written all those years back, had been fourteen thousand six hundred; the extra one hundred forty-one had been dug out of the ink-bleed cells one at a time. The year of the promise she had done the arithmetic—twenty a day, done in two years. It took nineteen. The whole back half of the days went into that last hundred and forty-one.
The archive copied the summary page; the original went into the record, the copy went into a frame hung beside the cabinet. The frame was new, the glass well wiped. She stood in front of it a while. Nineteen years, fourteen thousand and more numbers—spread out, just this one page.
The day the cabinet closed, Lu Weiming was seventy-six. He took his own two volumes off the table; the machine had finished scanning them long ago, but he still came every day, sat to one side and watched the others verify. Someone told him to rest. He said: You do the checking. I look at the paper. The feel of paper in the hand—no machine replaces it. He turned the key back in to the archive and signed the register. There was a spare; he put it in her hand and said: You entered the numbers. You keep it. Nothing more. Going out, he looked back once at the cabinet. No writing on the door. He said: That's as it should be. The cabinet needs no words on it; the numbers are all inside.
She was back at the station in November.
The air in the station had changed. The machine room was working overtime; the lights in the tracking room burned all night; people you passed in the corridor walked faster than usual. She went to the handover room for that day's telemetry daily and found a plot spread on the table: forty-four impactors in transit, attitude residual against time, one line per impactor, every line bending upward.
Bending faster than it should. The factory tolerance said 1.5 percent; by the old experience, the first three years in orbit should stay well inside it. But the new batch had been up only three months, and in the first four spot-checked the residual drift had reached 1.2 percent. Extrapolated on that slope to first strike: 8 percent.
She studied the plot twice. She knew the shape of those lines—twenty years ago, before Wangshu-7 was lost, Wei Xiangdong had given her seventy-three lines, an annual drift of 10.3 percent against a factory figure of 1.5. What he'd said then: twelve years in orbit and no one had ever measured it. Now it had been measured, and it was all the same. She sent Wei Xiangdong a message with a photo of the plot. The reply came the next day, one line: My seventy-three lines only rank in the forties. Your forty-four are in better shape than mine were.
The automatic orbit-injection software had the factory tolerances written in stone. A residual out of limits and the software refused to sign the correction, handing the shift over to procedure. Changing the software meant a change process, ninety days; by the time it cleared, first strike would be two months past.
The meeting argued for three nights. The first night was about whether to change the software: ninety days sat there on the table, and no one would sign the expedite—an expedite signed is an error owned. The second night was about whether the extrapolation held; some held the drift would saturate on its own, the slope bending back, and had no evidence either way; both sides were betting. The third night, the engineering group laid out the forty-four impactors by batch, factory inspection sheets, three months of in-orbit residual, side by side: the drift owed nothing to batch, something to attitude, and tracked time in orbit. That 1.5 on the factory sheet had been measured on the ground, not in the sky.
On the third night, Hu Yisu put a single page under the projector: manual orbit injection, machine doing verification only. Seven people, eight hours a shift, one signature per shift. He said: The software's error is that it believes the factory values. People don't believe factory values. People believe their eyes. Someone asked: human eyes on forty-four stars, several hundred quantities a shift—can eyes hold? He said: That's what training is for. This shift, he said, he had been standing for half a year.
The roster was drawn up on the spot. Seven names, seven days a week. His was on Wednesday. Engineer Ma was on the list—the Xiao Ma who had once computed 468,000 years on night duty, now head of shallow-cut data—and he had put himself on it, his remarks column reading: I compute slowly, but I compute to the end. The sheet was printed and taped to the handover-room wall: seven names in a column, seven signature cells trailing after, the paper changed monthly. An old hand passing glanced at it and said: Looks like the boiler-room roster of my young days. No one answered—but the sheet was laminated the next day.
Only when she saw that roster did she understand: the telemetry daily's signature had switched to a rotation half a year ago, seven names a week. That wasn't a division of labor; it was a trial run. Half a year of training, trained for exactly this. Afterward someone asked her: why aren't you surprised. She said: The year I met him, he was counting lost probes. Twenty-seven launched, six lost, sample size six—counted by him. A man like that rehearses shifts six months early. Nothing strange.
As the meeting broke up, someone in the corridor recognized him, a young voice, holding itself down: The streamer's back? He waved a hand: Not a streamer. On duty. The line was out of the building that night; the next day, downloads of the official daily doubled.
Wednesday night she went to the machine room. Hu Yisu stood the first shift. She brought the bone-conduction rig in with her; the gatekeeper logged it by the book: equipment carried in, model, purpose. At the purpose field she thought a moment and wrote: listening. The gatekeeper turned the book around for her signature; she signed. The page lay open, a full page of it—every other line said maintenance, calibration, borrow, return. Hers was one word. The gatekeeper looked at it, asked nothing, and closed the book.
Saturday's call went as usual. Zhou Yao was at the other end carving her block, carving a while, looking up to ask one thing. The last thing she asked was: Busy on your side? Zhou Yan typed: Listening to a star walk. Zhou Yao looked at those words a while and sent: Listen closely for me. She didn't ask which star.
He had asked her there to listen.
Forty-four in transit, one correction per impactor per shift. He took three days of corrections, ordered them by star number into a sequence, and wired it into her bone conduction—one line a second, the size of the correction becoming the height of a tone; forty-four stars, seventy-two hours, unrolled into one long string. He said: Machine verification only catches what's out of limits. What's inside limits but wrong—it can't catch. You listen.
Pitch was hers to choose. She chose the octave down, everything pressed into the band of frequencies her left ear had left. Bone conduction doesn't go through the ear, but she was used to letting what remained follow along, the way lips move over text. Half a column of trial layout and she said: too low—raise it two degrees. Again, and she said: that's it.
She listened three times. The first pass for the whole: long tones, short tones, even. The second at half speed, segment by segment—an hour moved through only half a column. On the third pass one tone came out of the sequence: uneven. Steady steps before it and after; at it, a half step inserted. A line of footsteps, and one step out of step. She said: Twenty-nine. They ran that stretch back alone; she listened again and said: It's not my ear. It's out of step.
They pulled the twenty-ninth impactor's raw telemetry. The corrections themselves were inside limits, but its differentials ran ragged—a quantity that should grow evenly came in stutters. The recomputation ran to dawn; the first two hours turned up nothing, the quantities were good quantities. Past midnight they changed roads and went after where the quantities came from: attitude-control plume had contaminated the sensor. The weight was fine. The weight stone was dirty. They changed the estimator, reran the sequence, and it lay flat. Morning briefing, all seven present; no one spoke; each traced his own name once more on the shift sheet.
The next day a line appeared in the appendix of the operations procedure: manual verification may attach an aural check. The issuing column carried all seven names. Hu Yisu had drafted the procedure; the appendix line was written in by hand, never typeset. Someone asked if that wasn't irregular. He said: The regular channels should have stopped No. 7 twenty years ago. The room was quiet a while. No one took it up.
Before dawn on Thursday, Hu Yisu was pulling old telemetry from the silence period. The in-transit leg of first strike needed a differenced background, and those hundred days of 2022 were the only clean floor the whole system had ever run at low emission; it had to serve as the template. File after file came up, up the uplink corridor. The uplink log's format hadn't changed in twenty years: time, command source, instruction code, basis column, signature column. He paged along line by line and reached February 1: a group send, the instruction code a shutdown code, the basis column a list number.
She sat to one side checking her own numbers. She had drafted that list twenty years ago too—the list of transmission activities not to be stopped during the silence, nineteen hundred and some exemptions, navigation accounting for eight parts in ten. The day the list took effect, the system sent the shutdown order out by attached table: those not listed, shut down.
The uplink log was complete. February 1, 2022, group send, shut down per the attached table. No. 8 stood in the exemption column—navigation benchmark. No. 7 did not. No. 7's daily call, three watts, had been classed as stoppable that year; it was not listed. The command source read: system. The signature column was empty, only a serial number.
The order took effect; No. 7 ran its self-check; the safe-mode switch takes eighteen days. On the nineteenth day, the call stopped.
Twenty years of investigation, all of it into why No. 7 sent nothing. No one checked what the ground had sent. In the early years the case files included one volume on ground-command review, its finding one line: no anomalous commands found. The sentence was true—a shutdown by table isn't an anomaly. It's by the book.
She called up the original list and turned to the end of the attached table. Those five words she had written herself: those not listed, shut down. The signature was her staff number. Below the printed last line of the table stood one more line in her small hand, added that year for fear someone would miss it: stations, please check for omissions and report within three days. The reporting window passed; not one station reported No. 7.
She printed that page, one copy, and put it in the 3t folder. Said nothing. Hu Yisu said nothing either; he copied the log for her and went back to laying out his template. Only the exhaust fans sounded in the machine room.
The template ran into the small hours. The silence-period floor was unnaturally clean—low emission is low emission; a hundred days, not one line of noise. He looked at that flat line and said one thing: It hasn't been broken these twenty years. It's been waiting for one command that would let it speak. Then he went on laying out, head down.
The nineteenth day. She ran the number through her head once. It matched. Matched, and that was all of it.
The station's countdown page changed format. The page was built by station people themselves; at first only one line: how many years left. Then it cut to months, months to weeks, and in mid-November, to days. Every format cut, the one on duty that night added a line at the foot of the daily, each note shorter than the last. The last note was: days. One word.
At night she finished the S table—line 7,230, 0.37, signed—and opened that page in passing. Below the number ran a line of small type, added on November 15, unclaimed: one hundred sixty-five days left. She looked at the small line a while. Song typeface, sixteen point—not the look of something dashed off. Most likely, she thought, another of the night-shift people; a man who has practiced his signature for half a year wants a place to put his half year down.
The desk calendar stood at the corner. The fold in the April page was still there. She pushed the calendar deeper into the desk and left the screen up. The civilian mirror page had put the days in too, laid out differently from the station's: the station's in big white figures, the mirror's in small gray ones trailing the depth column, one number at a time, keeping it company.
165 days left.