The dead world blinked at Sairu while she had both arms inside radiator bank seven.
Her helmet display had painted a false hot seam along the bank's shielded edge, and she was halfway through proving it false when a second line appeared far below: green-white, straight for twenty kilometers, then broken into three blocks. The blocks held their proportions while the station rolled and the earth slid beneath her boots.
Sairu braced one knee against the service rail and magnified the radiator sight. The false seam vanished under proper focus. The ground lights did not.
They lay across dark terraces at the edge of a cloud mass, too regular for any lesson she had been given about the surface. Eight hundred and twelve years ago, the last ground habitats had failed. Since then: poisonous air, sterile soil, weather wearing down empty works. Every child aboard learned the sequence before they learned the station's pressure alarms.
Three luminous bars faded. Another set brightened.
Sairu knew the shapes because she spent her shifts obeying them. The old service script survived on isolation collars, pressure doors, and the undersides of panels nobody had thought worth replacing. The first block meant ABOVE. The second meant WORKER.
The third was the question mark stamped beside manual overrides.
"Control, bank seven," she said. "Hold roll compensation on my visor."
"For the hinge test?" the duty operator asked.
"For my eyes. Ten seconds."
"That's not a test category."
"Then call it glare."
The stars steadied. Below, the lights went out in strips from west to east. Darkness remained for six breaths. Then the whole message returned, except that the middle block had changed. Not WORKER now. LIVING WORKER: the little diagonal that distinguished a warm hand from a powered tool.
ABOVE LIVING WORKER?
Sairu's free hand found the tether clip on the service rail and checked it, though it was already closed.
At the southern edge of the terraces, several tiny heat traces moved between the bright strips. The sight could have manufactured one bad pixel, not warm bodies crossing separate rows. Magnification broke each bar into terraced reed beds, thousands of pale tips kindling like a field of stars only after a person reached them. Star-reeds, for lack of a name. A touch at the head of a row lit its whole length, and a second touch put it out, so a handful of people could write across kilometers. The trace cooled; the reeds shone. A mechanism could store and shape living work, never begin it. One trace was smaller than the others and darted twice back to a patch that had failed to shine.
More glyphs opened around it, awkwardly spaced.
PIRU. CHILD. ASK.
The name had been made from service-script sound signs, each one kilometers long.
"Bank seven?" the duty operator said. "Your ten seconds are gone."
Sairu saved the raw frames without classifying them. A contact classification would dispatch the station's survey routines. She knew that. Her thumb still hovered over the tag until the small heat trace crossed a blazing row and vanished into the cooler dark beyond it.
"Glare cleared," she said. "Continuing inspection."
The ground fell behind the horizon. Bank seven waited with its ordinary fault: hinge twelve had taken four-tenths of a second too long to turn.
Mechanisms answered when touched. That was why Sairu liked them. A stuck hinge gave resistance, heat, a measurable delay. You found the cause and worked it until the answer changed.
For the rest of the inspection, the old question stayed at the bottom of her visor.
ABOVE LIVING WORKER?
Lassan watched the frames three times before saying anything. The maintenance archive occupied a narrow compartment between the machine shops, where cabinets built for physical labels stood beside newer storage columns. He kept a bowl of sour yellow berries on his desk. He pushed it toward Sairu without looking away from the ground.
"No, thanks."
"They're going soft."
"That doesn't improve them."
"It improves the urgency."
On the wall, Piru's name burned across a continent of darkness.
Sairu pointed. "You read it."
"I recognize four signs and a question marker."
"You read more than that."
"ABOVE is secure. The distinction between worker and living worker is secure. This could be CHILD, or junior, or restricted access by minors." Lassan enlarged the first and second displays until the terrace boundaries showed. "The change is important. Someone revised a category."
"Piru."
"Likely a name. It could identify a crew, a district, a tool series—"
"A tool series didn't run back to fix a dark row."
Lassan looked at the moving heat traces. He rubbed one thumbnail over the edge of his desk. "No."
"Then why are we talking about tool series?"
"Because the frames can support living operators and an intended question. They do not support a surface census, a history, or the age of the smallest operator. Not yet."
He brought up a service label used on coolant junctions two decks below. Its letter forms had rounded over centuries of recutting, but ABOVE and the living-hand diagonal were there. Beside it he placed a label scan from the station's founding hull. Piru's grammar resembled the older one.
"They preserved it," Sairu said.
"Or inherited something that shares its source. The oldest forms are closest."
"Eight centuries of empty-world instruction, and you want to correct my verb."
Lassan didn't look up. He tapped the founding-hull scan, then the ground frame beside it. "Look at the diagonal. That little hook on the end. Nobody up here has cut it that way since the founding hull. I've only ever seen it in rubbings." His finger stayed on the hook.
The compartment door opened behind her.
Orvek did not ask why a radiator mechanic had put a private optical hold on ground-facing frames. Her wrist slate already showed the access trail.
"You used glare authority," she said.
"There was glare."
"On the night side. Looking down."
Lassan quietly moved the berry bowl away from the edge of the desk.
Sairu showed Orvek the changing message. She watched the supervisor's eyes pause on the heat traces, then return to the time code.
"Next useful night pass?" Orvek asked.
"Fourteen hours, fifty-one minutes. The terraces will be within bank seven's surface angle for ninety-four seconds."
"And you want?"
"To answer."
"That isn't a radiator function."
"It was written to a worker," Sairu said. "Bank seven is mine."
"How?"
Sairu heard herself speed up. "We can give them one packet. Shielded face for dark, emissive face for bright. Their pattern tracks the station. They must have a heat sight. Four vane groups are enough for low-resolution blocks. We confirm we're alive, confirm Piru was seen, ask for receipt."
"Closing four groups stores heat in the spine."
"For less than a minute."
"At current load?"
"Thirty-eight seconds below the conservative limit. Forty-seven below mandatory abort."
Orvek turned to Lassan. "Do we know they'll read it?"
"We can't. The old script gives us a defensible order: ABOVE, LIVING, RECEIVE. Their display suggests the same reading direction."
"Do we know Piru is a name?"
"No," he said. "A name is the best fit."
Sairu pointed again at the small trace. "They asked whether a worker lives up here. We do."
Orvek didn't look at the trace. "The contact tag. Did you apply it?"
"No."
"Did you nearly?"
Sairu rubbed her thumb along the side of her finger and did not answer.
Orvek pulled the thermal record from bank seven. "One packet. No contact tag, no locator request, no networked optics. Local heat-eye only. Thirty-five seconds, because your hinge twelve is already late. If spine temperature crosses yellow, all groups open."
"We can do it in thirty-eight."
"Then remove three seconds of message."
"Which three?"
"You pick them. Put the optical excursion in the maintenance log."
"That will expose it."
"I know." Orvek signed with one thumb. "It goes under my authorization."
Sairu took the slate. On a hinge report the authority field stayed blank; now Orvek's print sat in it, above the thirty-five seconds and the yellow abort. Sairu had been ready to argue for the other three seconds. She let them go.
"Fix twelve first," Orvek said.
Fourteen hours later, hinge twelve still lagged.
Sairu had replaced its drive braid, cleaned the bearing track, and run it through a hundred turns. Unloaded, it matched the rest. Under radiator heat, it came late by two-tenths of a second—better, not good.
"Two minutes to surface angle," Orvek said from the supervisor's board across the radiator hub. "Bank spine at sixty-one."
Sairu floated beside the manual console. Lassan had strapped himself at the script display behind her, a paper copy of the packet tucked beneath one hand as though electrons might become careless.
"Sixty-one is cold," Sairu said. She ran twelve through one more unloaded turn. It landed with the others. It always did unloaded.
Orvek said nothing for a minute, then read the number out again. "Sixty-one."
Lassan pressed the paper copy flatter against the display frame. "The RECEIVE block stays RECEIVE. Not SEE."
"You changed that twice," Sairu said.
"Because SEE implies an eye. RECEIVE allows a sensor, a reader, or a—"
"We have thirty-five seconds."
"Surface angle," Orvek said. "Talk later."
The world's night opened on the hub display. The terraces were dark, a faint ribbed geometry in infrared. The heat-eye's reticle jumped onto the grid without her touching it and locked there, and a coordinate line blinked into temporary memory at the corner of the display. Sairu had no hand free to clear it. She selected four vane groups. Their emissive faces glowed on the station's outer cameras; their shielded backs disappeared against space. From below, through a powerful enough heat-eye, the whole radiator would become a label board crossing the stars.
"Packet one," she said. "Mark."
She closed two groups and left two open: ABOVE.
"Hold three," Orvek said. "Turn."
Sairu moved the next combination through LIVING. The four indicators changed together except twelve, which hung amber and snapped over late.
"Hinge lag point three," she said.
"Spine sixty-seven. Continue."
WORKER took six turns. RECEIVE took eight. Piru's sound signs were worse: the old service script had never been designed to name children, only couplings and hands assigned to them.
"Seventy-four," Orvek said. "Twenty seconds to yellow."
"Piru marker beginning."
"Order error," Lassan said. "Second sound first."
"That's what I have."
"Your lower pair is inverted."
Sairu looked. Hinge twelve had left a bright corner where the block required dark.
"Resetting."
"No reset," Orvek said. "Thirteen seconds. Shorten."
Sairu abandoned the name. She turned the groups through RECEIVE once more and then the service glyph for RETURN SIGNAL. Twelve struck its stop hard enough to send a tremor through the console.
"Yellow," Orvek said. "Open all."
"One confirmation mark."
"Open all."
Sairu's hand stayed on the controls for one hot, stupid beat. Then she obeyed. Emissive faces swung toward space. Heat poured out of the spine in a rising red wash.
Cloud had already reached the western terraces. A pale bank crossed the signal field, swallowing row after row. Nothing lit beneath it.
"Did they receive?" Sairu asked.
Lassan scrubbed through the ground frames. "No display visible."
"That isn't what I asked."
Lassan ran the same forty seconds of cloud back again. "I don't know."
"Bank spine declining," Orvek said. "Hold full emission. Sairu, hinge twelve is now point six late."
Below, the last clear terrace vanished under cloud.
They had said they were alive. They had failed to say to whom.
The station made them wait fifteen hours and nine minutes for another usable angle.
Sairu spent the first three repairing hinge twelve. A hairline distortion in its hot-side stop had escaped every unloaded test. She replaced the stop, ran the group hot, and watched four green indicators turn together. That answer should have satisfied her. It did not.
She found Orvek in the small galley beside radiator control, eating lentils from a pouch while reading the excursion log.
"Any change?" Orvek asked.
"Twelve is clean to point zero four."
"Good," Orvek said. "On the ground."
"Cloud."
Sairu hooked a foot under the opposite restraint. "They repeated before. If they saw us, they'll repeat."
"Probably."
"They will."
Orvek squeezed the pouch flat from the bottom and didn't argue.
"You filed it under radiator maintenance," Sairu said. "Like it's a sticky hinge."
"I put an unplanned thermal excursion under radiator maintenance because it was one. I put the unexplained optical pattern under a safety hold because that keeps the raw frames local until review."
"Review by whom?"
"Someone who isn't running on half a sleep cycle. Have you eaten?"
"Yes."
Orvek waited.
"A roll," Sairu said.
"Get another."
She caught Lassan outside the archive. He carried two label rubbings and had yellow berry juice drying on one cuff.
"The packet was readable," she told him.
"Parts of it."
"We answered."
"We emitted a syntactically plausible sequence toward the observed grid."
"Do you practice making everything sound dead?"
He didn't answer. He pinned the rubbings against his chest and held out his slate. The heat-eye's locked coordinates had filled a standard contact form: the terrace grid centered in a red square. Eight observing systems were listed beneath it, ready to acquire the same coordinates on approval.
"Approval starts the search," he said. "Whoever works those rows never asked to be looked for."
"They made a question twenty kilometers wide."
He left the slate in her hand.
Sairu enlarged the image. Even after the cloud, faint cooling scars marked the rows used twice. The living-hand diagonal was paler than the terraces around it. At several points, the infrared record showed sudden drops where bodies had knelt to the reeds. The lights had not come free. Whoever tended those rows had spent stored sun from the plants and warmth from their own skin.
"I didn't apply the tag," she said.
"I know."
"I knew what it did."
Lassan tucked the rubbings under his arm. "Before or after your thumb stopped?"
She pushed away from the wall too hard and had to catch the next rail.
On the third pass, the cloud broke into long gray islands. Between them, the terraces shone.
This time the blocks came tight and quick, one after another at the grid's northern edge.
ABOVE. LIVING. RECEIVE.
Then Piru's name, its lower pair of sound signs in the order Lassan had drafted, not the one hinge twelve had sent. The child had received enough of their damaged packet to identify its intended recipient and correct their spelling.
"Receipt confirmed," Sairu said.
"Piru attribution strongly supported," Lassan said.
"Bank spine fifty-nine," Orvek said. "Keep watching."
The grid changed. One small mark brightened beside Piru's name. Six marks opened beside LIVING HANDS. The heat-eye showed bodies moving with them: the small trace and several taller ones, one person working two rows when a bleached strip failed.
"Seven operators," Sairu said.
"Seven markers," Lassan said. "Several operators visible."
The marks faded. A new sequence began, using warning terms Sairu had seen on survey mounts.
NO EYE.
Her hands tightened around the console grips.
"They want us to stop looking," Orvek said.
"Then why send again?"
"Wait," Lassan said.
On the surface, two people crossed the lit rows. The first warning vanished. It returned with an extra block, but cloud shadow cut its lower half away.
NO EYE—CENTER.
"No centering," Sairu said. The contact form's red square seemed to float in her memory.
The terraces went dark long enough that Orvek called, "Thirty seconds to our reply angle."
Light returned in a longer, rougher order.
POSITION MARK: NO.
EYE MOVE: BELOW CALL FIRST.
The last terms were not elegant. CALL was the old label beside a manual service summons. FIRST had been inserted after the sequence, forcing three adjacent rows to bleach almost white. The small heat trace—Piru, likely Piru, only Piru if the evidence held—moved out of one cold patch and into another worker's arms.
Sairu took her hand off the reply controls and read the sequence again.
"The heat-eye jumped onto them by itself last pass," she said. "If they had anything looking back, maybe they saw it swing."
"Or they know what centered observation means," Lassan replied. "No coordinate record. No search unless they summon it. That reading fits all three revisions."
"Reply window," Orvek said. "Thirty-four seconds authorized. Same abort. What are you sending?"
Sairu had built six possible messages during the wait. Explanations. Assurances. Questions about the reeds, the language, the people beyond the grid. Every one now felt like reaching past the thing Piru had actually said.
"Manual status," she said. "Position not stored. Eye waits. Next dark pass, surface begins."
Lassan scanned the blocks. "Use READY, not WAITS. We don't know whether their grammar carries duration."
"Fine."
"And omit surface. BELOW is attested."
"Fine. Orvek?"
The supervisor studied the thermal forecast. "Twenty-nine seconds. We come out of shadow earlier this pass."
Sairu loaded the packet.
The vanes began to turn.
"Mark," Orvek said.
POSITION. NOT STORED.
Hinge twelve landed with the others.
"Spine sixty-six."
EYE. MANUAL.
"Seventy-one."
NEXT DARK. EYE READY.
"Fifteen seconds."
BELOW CALL FIRST.
Lassan leaned toward the display. "Third block—"
"I see it." She had thrown the lower pair a beat early. She reversed it without resetting the message. "Mark."
"Seventy-eight," Orvek said. "Open."
This time Sairu opened every group on the word. The radiator brightened into its ordinary uninterrupted sheet. Heat left the station. On the surface, the terrace grid held dark.
For four seconds, Sairu thought that was the answer.
Then a single receipt mark appeared at the northern edge. It shone green-white, dwindled to infrared, and went out. The moving traces withdrew between the rows.
Orvek released her restraint. "I'm extending the safety hold. I'll take the audit when the deferred contact record surfaces." She looked at Sairu. "Disable automatic centering on this optical set. Local manual acquisition only. Put the change in my maintenance entry."
Sairu opened the configuration. The grid's coordinates waited in temporary memory, not yet written to the survey ledger. She cleared them, then removed the acquisition set from automatic ground search. A warning asked whether she meant to reduce observational coverage.
She confirmed.
Lassan began his record beside her. He entered the attested glyphs, the moving heat sources, the number of visible tenders as a range, and the restriction in its three corrected forms. He did not write child after Piru without marking the translation uncertain.
Outside, hinge twelve and all its neighbors turned emissive faces toward the black. Sairu watched their temperatures fall into alignment, one clean gradient across the bank.
The next return window sat fourteen hours away. Until the ground chose to shine, there was nothing more for her hands to do.