The foreman brought a whistle, a chalk line, and a disagreement about the word safe.
“Safe enough to do the work,” she said, drawing the chalk across the floor of the chamber. “Not safe enough to invite my children.”
“That’s a useful distinction,” Iven said.
The foreman’s name was Brell, and she had been working the lower heat lines for eleven years. She knew the pipe’s rhythm by ear, could distinguish a bad bracket from a bad pump through a wall, and did not intend to let an expelled doctor and an unlicensed restorer turn her crew into a demonstration.
Sera seemed equally determined not to allow a demonstration that would get anyone hurt. Kesh wanted to observe the pale creatures without pretending she understood them. Iven wanted to keep the pipe attached to its mounting and everyone in the chamber alive. The four goals overlapped, but not so neatly that a chalk line could make them one thing.
At the chamber entrance, Tavin had parked a small maintenance cart carrying two folded barriers, a tool chest, and a coil of rope. He had agreed to bring the equipment because the line served Cage Seven’s heat supply. He had not agreed to stay.
“I’ve got a passenger run in an hour,” he said. “If you need the cart after that, you can push it yourselves.”
“We’ll try to finish before your excellent company becomes indispensable,” Sera said.
Tavin inspected the low opening in the wall. “I’d settle for finishing before one of those things decides my cart looks edible.”
The pipe had been running at reduced pressure since Iven had gone to the valve room. The reduction had cost him two hours, three explanations, and the pleasure of hearing a clerk describe a pipe failure as an inconvenient possibility rather than an emergency. He had finally found the shift engineer responsible for the valve and shown her the broken bracket. She had signed a temporary reduction herself.
The creature’s scrape marks were still visible around the mounting. Neri had examined the wall from the outside and suggested a plate that would bridge the damaged area without driving more bolts into the soft layer behind it. She had sent Dessa with the plate and clear instructions: no one was to install it until the tissue Sera wanted to inspect had been sampled, and no one was to call a plate a cure for a hole.
Dessa stood by the tool chest with the plate in both hands. “If it doesn’t fit, I take it back. I don’t bend it around something alive.”
“Agreed,” Sera said.
Brell pointed to the chalk line. “The drill stays here. The opening stays there. If I blow once, everybody stops. Twice, everybody leaves. No arguing until we’re through the door.”
Kesh nodded. “What if the whistle doesn’t work?”
“Then I shout.”
“And if you can’t shout?”
“Then you use your eyes.”
Iven liked Brell. He suspected she would find that less flattering than he intended.
The plan was small. They would observe the chamber with the pipe at its reduced setting, record whether any creatures appeared, and then briefly operate the drill against a separate, already damaged piece of scrap bolted to a stand. The scrap stood several paces from the wall. It was not a new hole in Mercy. If the noise or vibration alone brought the creatures, that would be useful to know. If nothing appeared, it would not prove the opposite. They would stop before anyone approached the opening.
Elian had brought a notebook and a watch. He stood where he could see both the opening and Brell’s hand. Kesh carried no spear today; she had a shield of layered leather and wood, a lantern, and a short hook for moving equipment without putting her fingers near it. Iven had his spanner, hammer, wire, and ordinary rope. He seated plate brace, spring step, and piston strike before entering the chalked area.
Sera stood nearest the mounting, but still behind the line. She wanted a sample from the dark fluid beneath the plate. Brell had allowed it only after the first observation and only if no creature was in the chamber.
“Ready?” Elian asked.
Brell lifted her whistle. Everyone settled into position. The pipe gave a quieter, regular pulse behind the wall. Drops of moisture collected on the grating and fell into the drain.
For the first ten minutes, nothing emerged.
That was long enough for Iven to become aware of the weight of his own breathing. He watched the opening, then the mounting, then the passage behind the workers. He disliked watching a single hole for too long. Dangerous things had a way of finding the places a person had decided not to look.
“Record that,” Sera said.
Elian wrote. “No movement observed. Reduced flow, drill inactive.”
“Record what we could see,” Kesh said. “Not what wasn’t there.”
He scratched out the first sentence and wrote another.
Brell gave the sign to start. One worker turned the drill’s crank slowly. The bit touched the scrap on the stand, producing a metallic chatter. The sound echoed against the curved wall. Dust shook loose from the drill guard and drifted through the lamplight.
Iven watched the opening. Kesh watched the wall around it. After perhaps thirty seconds, a clicking sound answered from somewhere behind the surface.
Brell raised one hand. The worker stopped the crank. The bit spun down.
The clicking continued for a few moments, then faded.
“Again?” Elian asked.
“Not yet,” Sera said.
She looked at Kesh. Kesh had moved her lantern toward a narrow seam above the opening. A pale foot appeared between the seam’s edges, gripped, and disappeared.
“There,” Kesh said.
Elian wrote the time. He looked up. “It may have been there already.”
“Yes.” Kesh kept her voice level. “And it may have heard the drill. We don’t know which.”
Brell lowered her hand. “We’ll run it once more. Same speed.”
The worker turned the crank. The bit chattered against the scrap. Iven felt a faint vibration travel through the floor, separate from the slow pulse of the pipe. The seam above the opening widened. A pale head appeared, followed by a long jointed forelimb.
Brell blew once. The drill stopped.
The creature did not immediately withdraw. It gripped the seam and lowered itself until its head was level with the opening beneath it. Its armor was mottled with mineral dust, and the ridge along its back had a dark break near the shoulder. It could have been the larger creature from the previous visit, though Iven would not have sworn to it.
The creature climbed down the wall.
Nobody moved toward it. It crossed to the damaged mounting and pressed its jaw against the edge of the plate. The scrape of mineral on metal sounded unnaturally loud after the drill had stopped.
“That’s enough,” Brell said. “We have what we came for.”
Sera had taken one step forward without seeming to notice. She stopped when Brell spoke.
The creature turned toward her.
Iven shifted his weight, ready to block. It did not lunge. Instead, it retreated beneath the pipe, then moved toward the drill stand. It touched the scrap with one forelimb and struck it once. The stand rattled.
The creature recoiled, but only for a heartbeat. Then it struck again, harder. One of the bolts holding the scrap to the stand jumped free and skittered across the floor.
Brell put the whistle to her lips. A second shape appeared in the low opening.
Two notes cut through the chamber.
The workers withdrew in the order they had agreed. Iven moved behind them with Kesh. The first creature remained by the stand, its head lowered. The second emerged only far enough for the light to catch its forward legs.
Tavin had left his cart just beyond the door. The workers reached it without incident. Sera came last except for Iven and Kesh, carrying the sample case she had not yet opened.
“Do we close the door?” a worker asked.
“Not on the cart,” Tavin said. “And not on anyone’s hand. Pull it clear.”
He and the worker shifted the cart into the side passage. Brell closed the chamber door and slid the bolt into place. The sound of the creatures beyond it was faint, but Iven could hear something striking the drill stand.
Elian leaned against the wall and checked his watch. “We were in there eighteen minutes.”
“Long enough to see one come out when the drill ran,” Kesh said.
“And long enough to see it didn’t leave when the drill stopped,” Sera added.
Brell took the whistle from her mouth. “Long enough for my crew to decide they don’t want to run that machine again today.”
No one argued. The test had produced an observation and also shown how little space there was between observing a creature and standing in front of it.
Tavin checked the passage behind them. “My passenger run leaves in twenty minutes. If we want the cart out, now would be an excellent time to become less scholarly.”
They pushed it up the incline. Iven took the rear handle with his left hand and used the right only to steer; his knuckles were better than the previous day, but the cart’s wooden grip found every sore place. At the next landing, a woman in a blue work apron stood beside a service hatch with a lamp held over her head.
“Brell,” she called. “The valve room sent me.”
Brell stopped. “What changed?”
“They want the heat flow restored before the evening cycle.”
“We aren’t finished.”
“I’m not the one who asked.” The woman handed her a folded note. “The shift engineer says she can hold the reduction for another hour. After that, the upper line will start losing pressure.”
Brell read the note, then gave it to Iven. The engineer had written a pressure estimate and signed her name. It was not a threat. It was a statement of what the system would do if one part remained restricted while another continued to draw heat.
“We can put the bridging plate on the mounting,” Iven said. “If the chamber’s clear.”
Dessa looked down the passage. “And if it’s not?”
“We wait.”
“The upper line won’t.”
“No.” He folded the note. “But we can ask the engineer whether she can reduce the draw at the terraces for one cycle.”
The woman in the apron gave him a skeptical look. “You can ask.”
“I’m getting good at it.”
Sera took the note and read the numbers. “If the flow returns before the mounting is covered, the damaged tissue may take another impact.”
“May,” Brell said. “We don’t know what the creatures are doing to it either.”
Kesh’s face tightened. “Then we find out without sending someone in to make it worse.”
They agreed on a second inspection after the shift engineer had answered. Brell sent two workers upstairs with the request. Tavin left with his cart, taking the barriers and tool chest; he promised to send a handcart back if they needed one. Dessa kept Neri’s bridging plate and carried it to a shelf outside the chamber, where it could be reached quickly without being dragged through the narrow door.
Iven and Elian returned to the chamber door. A small viewing panel had been cut into the upper section long ago, its glass clouded with grime. Iven wiped a clear patch with his sleeve.
The drill stand lay on its side. The first creature stood over it, worrying at the torn guard. The second was no longer visible. The dark fluid beneath the mounting had spread into a narrow line across the wall.
“Can you see the opening?” Elian asked.
“Only part of it.”
“Then we can’t say the second left.”
“Correct.”
Elian made a note. He had begun doing that without trying to make every observation fit a conclusion. Iven appreciated the habit. It was slower than confidence, but it tended to break fewer things.
Behind them, a series of knocks came from the service hatch. The woman in the blue apron had returned.
“The engineer can hold the reduction for two hours if the terrace kitchens switch to stored heat,” she said. “She’s arranging it now.”
Brell let out a breath. “Good.”
“She also wants a written plan for the mounting before anyone puts the flow back.”
“Even better,” Neri said from the stair. She had arrived carrying a smaller packet of bolts and a roll of cloth. “Someone upstairs has discovered the joy of asking before opening a valve.”
Iven stepped away from the panel. “The creatures are still inside.”
“Then we make the plan while they think about leaving.” Neri set the bolts on the shelf. “Dessa says the plate fits the measurements. I brought a second set of brackets in case the first set hits something we didn’t see.”
She listened as Kesh described the observation. She did not tell them what the creatures meant or why they had appeared. She asked where the pipe moved, how much space remained around the plate, and whether a worker could reach the mounting without standing in front of the opening.
“From the right,” Iven said. “There’s a narrow ledge behind the tool rack.”
“Then we’ll clear the rack first. If the chamber isn’t clear, we don’t go in.”
Brell looked at the note from the valve engineer. “And if it stays occupied for two hours?”
“Then we tell the engineer and decide what to protect first,” Neri said. “We don’t pretend a clock makes the creatures disappear.”
That answer did not please anyone. It was still the best one available.
Iven looked through the panel again. The first creature had moved away from the drill stand. It stood beside the damaged mounting with its head pressed against the wall. The pipe pulsed once beneath it. The creature did not move.
He could not tell whether it was listening, feeding, guarding, or simply resting. He could tell that the crew would need a better plan than opening the door and hoping.
“Let’s draw the approach,” he said.
Neri unrolled a clean sheet on the shelf. Elian held one end down with the valve note while Iven marked the pipe, the mounting, and the narrow ledge. Kesh added the low opening and the seam above it. Brell marked the door and the point where her crew would stop if the whistle sounded.
The drawing looked small compared with the chamber. It contained enough room for a pipe, two creatures, and several ways for people to be hurt.
It also contained a path out. Iven made sure that line was the darkest one on the page.