The next morning, the creatures ignored the wound.
Iven watched two pale shapes cross the chamber through the door’s viewing panel. One paused at the covered mounting, touched the edge of the plate, and moved on. The other went directly to the old drill stand. It pulled at the bent guard until a strip of metal came free, then carried the strip toward the low opening.
Neither approached the uncovered drain where dark fluid had collected in a shallow tray.
Kesh stood beside him with her notebook. “That isn’t what I expected.”
“What did you expect?”
“A line of them arriving to inspect the damage.”
“You didn’t write that down.”
“I didn’t want it to become the answer before we looked.”
Brell had arranged another controlled observation after Neri’s longer brace was installed. The pipe was running at the reduced setting. The cover remained in place. Sera had examined the previous samples and found living fibers in both, but she could not say whether the pale strands were produced by the tissue or deposited by the creatures.
The new observation was supposed to compare the guarded mounting with a second damaged site on the forward saddle. Instead, the first site had produced behavior that did not fit Kesh’s neatest expectation. Iven considered that a useful beginning, though he would have preferred useful information that did not come with teeth.
Elian stood at the junction with a copy of the time sheet. Neri had gone to the forward saddle with Sera to inspect the wash-platform frame. They would record any creature movement there while Brell’s team watched the heat line. A runner would carry messages between the two sites; the distance and the lift schedules meant the observations would not be simultaneous to the minute, but they could be compared afterward.
The smaller creature disappeared into the low opening with the strip of metal. The larger one remained beside the drill stand. It shifted its weight from one forelimb to the other, scraping the grating.
“Could it be collecting material?” Iven asked.
“Could be,” Kesh said. “Could be moving the guard away from the pipe. Could be chewing it because it likes the taste.”
“Do you think it likes the taste?”
“No. But I don’t know.”
Brell came to the panel. “The foreman on the next line says his crew saw one near an intact wall. No drill. No leak.”
“Did they see it attack?” Kesh asked.
“They closed the door before they found out.”
“A sensible crew.”
“They’re proud of it.”
Brell unfolded a scrap of paper. The other foreman had written the location and time. Elian added it to the sheet, marking it as a report rather than a direct observation.
“Maybe they’re patrolling,” he said.
“Maybe,” Kesh replied. “If the other wall is intact.”
“Do you want to see it?”
“Yes. After this interval.”
Iven shifted aside so Brell could look through the panel. The creature beside the drill stand had stopped moving. Its head rested on the bent guard. For several moments it looked almost asleep.
Then the pipe above the mounting gave a hard knock.
The creature’s head came up. The longer brace flexed, returned, and held. A second knock followed, sharper than the first. The washer Iven had placed on the plate jumped and fell to the floor.
Brell blew once. The people in the junction stopped talking. Through the panel, Iven saw the creature turn away from the stand and run toward the mounting.
“The pipe’s under the same setting,” he said.
“Unless someone changed it again,” Brell replied.
She sent a worker to the valve room. Iven watched the plate. The frame did not appear to be failing. The movement came from behind it: a slow inward pressure that had increased enough to push the plate against the pipe.
The creature reached the cover and struck it with a forelimb. The metal rang. It struck again, then began scraping at the lower edge.
A dark line appeared beneath the cover and spread across the wall.
“The tear opened,” Sera would have said. Iven could not know that from the line alone. He could see that fluid had escaped where it had not escaped before.
The creature pulled the cover’s lower corner. The bolt held. It tried again, using its jaw this time. The corner bent outward.
Brell brought the whistle to her lips, though no one was inside. “If it tears that plate loose, the pipe can move again.”
“We can’t stop it from out here,” Iven said.
“We can close the branch.”
She sent another worker to the local shutoff. The wheel turned smoothly now that Iven had cleared the old paint from the spindle. The pipe’s hum softened. The creature kept pulling at the cover.
Kesh touched the panel. “It didn’t react to the fluid in the tray. It reacted after the pressure changed.”
“Or after the wall moved,” Iven said.
“Or the sound.”
“Yes.”
The cover’s lower bolt gave way. The creature carried the bent piece toward the low opening, but it was too wide to fit. It pushed once, backed up, and left the piece on the floor.
The runner from the forward saddle arrived out of breath. “Sera says the wash platform moved too. The block under the frame shifted, and the split got wider.”
“When?” Elian asked.
The runner checked the note she carried. The time was close to the first knock in Brell’s chamber. It was not exact; the two watches had been set together that morning, but the runner had spent time getting through the lift queue.
Neri had added a line beneath Sera’s note: Do not increase pressure. Bring a longer support.
Brell read it. “The other wall moved at the same time.”
“Perhaps,” Elian said. “Close enough that we should compare the full records.”
“Meanwhile the pipe is shut,” Brell replied. “The workshops on this branch have no heat.”
Iven looked through the panel. The creature had returned to the exposed mounting. It pressed its head against the damaged edge, then scraped at a strip of sealant hanging loose. The sealant came away. More dark fluid ran down.
He did not know whether the creature was cleaning the wound, enlarging it, or doing something unrelated to either. He knew the mounting could not remain exposed while the wall continued to move against the frame.
“We need to support the wall without trapping it behind the plate,” he said.
Brell gave him a look. “That’s a good sentence. Can you build it?”
“With Neri.”
“She isn’t here.”
“Then we wait for her drawing.”
The creature turned toward the door. It moved closer, stopping only a pace beyond the threshold. Its mineral plates were not smooth. Fine ridges crossed them, and small patches of dark material filled the gaps where the armor had cracked and grown together again.
Kesh lifted her notebook and sketched the head. The creature touched the door with one forelimb. Its hooked foot scraped down the metal, leaving a pale line.
“Does it know we’re here?” Elian whispered.
“I would,” Iven said.
The creature struck the door. The frame shook. Brell moved the workers back toward the stair. Iven remained at the panel long enough to see the creature turn away and go back to the mounting.
“It isn’t trying to get through,” Kesh said.
“It could change its mind.”
“Yes.”
The runner returned to the forward saddle with Brell’s note. Iven went to the workshop to find material for a movable support. He chose two lengths of flat bar, a hinge, and a pair of padded blocks that could be adjusted without reaching behind the wall. Jem helped him cut the bars. The hinge came from a storage cabinet whose door had been replaced; Iven cleaned it but did not acquire an imprint from a functioning part merely because he handled it.
“That’s a lot of work for something we may not use,” Jem said.
“That’s how I like my emergency equipment.”
“Unused?”
“Available.”
They assembled the bars with ordinary bolts. Neri’s runner returned before the work was finished, carrying a sketch of a similar support and a note that the wash-platform frame had shifted again. Sera had seen a small amount of fresh fluid at the split. No creature had appeared while she watched.
Kesh read the note twice. “The two sites moved at nearly the same time. One drew creatures, one didn’t.”
“Could be different passages,” Iven said. “Or different damage. Or the creature at the second site was somewhere we couldn’t see.”
“Could be all three.”
Jem tightened the hinge bolt and tested the movement. The bars opened and closed without binding. Iven added a stop so they could not fold under load. The support was not elegant, but it could be installed from the chamber side and adjusted as the wall moved.
When they returned, Brell had made a decision. “We aren’t opening the door until Neri gets here. The pipe is shut. The workshops have temporary heat for the afternoon.”
Iven set down the support. “Good.”
“You were going to argue.”
“I was going to offer this.”
“Then you can offer it when she arrives.”
Kesh went to inspect the intact wall on the neighboring line with Elian. Iven stayed at Brell’s chamber. He used the quiet to repair the bent base of the maintenance jack: remove the screw, straighten the plate against an anvil block, check the threads, and reassemble it. The repair restored a tool he already knew. It did not produce a new imprint. He preferred having a working jack to inventing a story about why the graft should reward every turn of a spanner.
Neri arrived with Sera and a worker carrying the forward site’s measurements. She examined the movable support and changed the placement of one padded block.
“The wall needs room to move,” she said. “If we hold it rigid, the force goes somewhere else.”
“Where?” Brell asked.
“Wherever the next weak piece is.”
“Useful.”
“It’s the most useful answer I have.”
They fitted the support while the chamber was clear. The creature had retreated through the low opening, leaving the bent cover on the floor. Iven and Neri worked quickly but did not rush the bolt threads. The new support contacted the frame at two points and left a gap around the damaged surface. Sera checked the gap before they withdrew.
The next inward movement pressed against the padded blocks. The support yielded slightly, then returned. The plate stayed clear of the pipe.
Brell opened the branch valve one step. Heat began moving toward the workshops again. The pipe hummed. The support held.
A pale limb appeared at the upper seam. It remained there for several breaths, then withdrew. No creature entered the chamber.
Kesh and Elian returned from the neighboring line with another inconvenient result. The wall described as intact had a crack behind a layer of old insulation. It was small and dry, but it existed.
“Which doesn’t prove the creature saw it,” Kesh said.
“And doesn’t mean every creature is looking for damage,” Sera added.
Elian laid the records side by side. “But we have three sites where damage and sightings occur near each other.”
“Near each other is useful,” Iven said. “It’s not the same as because.”
Brell handed the time sheet to Elian. “Write that down too.”
He did.
At the end of the shift, the crew restored the tools to their rack and left the chamber door closed. The pipe supplied heat at a reduced but workable rate. The wall still moved. The creatures still used the passages behind it. The tests had not delivered the clean answer Kesh had hoped for.
They had delivered a narrower one: damage and changes in pressure deserved attention, but a creature could appear without an active drill, ignore an exposed tray, and remain dangerous after the machine stopped.
Iven carried the repaired jack back to the workshop. The handle was warm from his hand. Behind him, Mercy’s slow movement passed through the deck as a familiar rise and fall. The wall below had moved on a different rhythm.
He wondered how many other rhythms the city had learned to call machinery because no one wanted to ask what else they might be.