The drill had stopped, but the pipe behind it had not.
Iven felt the vibration through the soles of his boots before he saw the machine. The maintenance passage sloped beneath the occupied decks, past damp beams and a row of inspection lamps. Its walls changed as they descended. Riveted plate gave way to a pale, uneven surface crossed by dark lines, some thicker than his wrist. Moisture gathered in the hollows and ran toward a grated channel.
Kesh led them around a bend where the passage widened into a work chamber. Four workers stood beside a rack of tools. None looked pleased to be waiting. A fifth sat on a crate with his hand wrapped in cloth and his boot braced against the wall.
“That him?” Sera asked.
Kesh nodded. “The one who pulled at the tool.”
The man raised his bandaged hand. “It was my tool.”
“An important distinction,” Iven said.
The man gave him a wary look. “I wasn’t trying to fight it. I thought the guard had caught on the pipe.”
Sera knelt beside him and unwrapped the cloth. Two shallow cuts crossed his palm. She cleaned them with water from a flask while he described what had happened.
The creature had come out of a side opening while the drill was cutting into an old mounting. It had seized the vibrating guard in its jaws. When he pulled, it had struck the back of his hand with a mineral edge. Another worker had shut off the drill, and the creature had withdrawn into the opening with a strip of bent metal.
“You saw a second one?” Kesh asked.
“Behind the first. Smaller, I think.”
“Did it come into the chamber?”
“I saw legs. That’s all.”
Sera wrapped his hand again. “The cuts need cleaning tonight. Tell someone if the swelling increases.”
“I’ve got a wife who’ll tell me before I know.”
“She sounds useful.”
“She is. Don’t tell her I said so.”
Iven went to the drill. Its long cutting arm rested against a mounting plate on the wall. The machine was off; the flywheel had stopped, and the crank handle was secured. A steel guard had been torn away from one side. The broken edge bore parallel grooves, as if something hard had bitten through it and dragged it sideways.
Beyond the mounting plate, a thick pipe ran into the wall. It trembled against two brackets. Each vibration sent a faint rattle through the tools in their rack.
“The pipe’s still under load,” he said.
The foreman, a stocky woman with a red scarf tied over her hair, joined him. “Heat circulation. We were replacing the mounting because the old bolts had pulled loose.”
“Who controls the flow?”
“Upper valve room. We asked for a reduction.”
“And?”
“They said the terraces need the heat.”
Iven put his fingers on the pipe. It was warm rather than scorching. The movement was regular, but the left bracket let it travel farther than the right. Every few strokes, the pipe tapped the edge of the loosened mounting.
“That bracket’s feeding the vibration into the wall,” he said.
“Then fix it,” the foreman replied.
“I’d like to know what’s behind it first.”
The foreman looked toward the side opening. “I’d like that too. But the pipe won’t wait because we’re curious.”
She was right. A loose pipe under continuous load could break its remaining bracket. If it did, the chamber would gain a much larger problem than an unfinished experiment.
Kesh crouched near the opening. It was low and irregular, about wide enough for a large dog. Pale flakes lay on the floor at its mouth. She pointed to a dark smear on the wall beside it.
“That wasn’t there before the drill started,” she said. “The crew cut into the mounting and found a soft layer under the plate.”
Sera joined her. The smear had dried at the edges but remained wet near the center. She touched it with a clean probe and examined the tip.
“Living tissue,” she said. “Or material from it. I need a sample to say more.”
The foreman folded her arms. “You think we drilled into the Marcher?”
“I think the wall isn’t only wall.”
“Everything here belongs to the Marcher. The pipes run through it.”
“Some things belong to it in a more immediate way.”
The foreman studied the smear, then the drill. “We were told the mounting was dead shell.”
“Who told you?” Iven asked.
“The drawing.”
He looked at the plate again. It had been installed long before this crew arrived. A repair drawing could accurately describe a plate and still say nothing about the material behind it. He knew that from experience. He preferred not to know it this well.
A scratch came from the side opening.
The workers moved back from the rack. Kesh raised a hand, and everyone stopped. The noise came again: a hard edge against stone, followed by a brief click.
Iven seated plate brace, piston strike, and spring step. He did not want to spend charge before he knew what was coming, but he wanted the patterns ready. Sera stepped away from the opening and took the injured worker with her. The foreman held a lantern high enough to throw light across the floor without putting herself in front of the hole.
A pale limb emerged. It ended in a hooked foot that gripped the edge of the opening. Another limb followed, then a low head armored in overlapping mineral plates. The creature’s body was long and compact, with six legs folded close beneath it. One plate along its shoulder was broken. The raw edge matched the fragment in Kesh’s bundle.
It did not look at the people first. Its head turned toward the vibrating pipe.
“Don’t move,” Kesh said quietly.
The creature advanced into the chamber. Its hooked feet clicked on the metal grating. It approached the loose bracket, raised its head, and touched the damaged mounting with the edge of its jaw.
The pipe knocked against the plate. The creature recoiled, then struck the bracket. Metal rang. One of the workers flinched and caught the tool rack before it tipped.
The sound drew the creature’s head around. It moved toward him.
Iven stepped between them with his forearm raised. He did not make the brace visible until the creature lowered its body. Then he spread a compact plate of pressure across his arm and the short length of pipe beside him.
The creature lunged. Its shoulder hit the brace hard enough to drive him back a step. He turned with the force instead of meeting it squarely, guided the armored head past his hip, and pushed the worker toward the door with his free hand.
“Out,” he said.
The worker did not argue.
The creature wheeled. Iven had seen the speed of its first attack and did not wait for the second. A short spring step carried him sideways. He struck the exposed joint behind its forward leg with a piston impulse. The creature stumbled but did not fall. Its armor scraped sparks from the grating as it turned again.
He could kill it. The joint was exposed, and he had enough room to drive the next blow through it. Behind him, however, the other workers had reached the doorway. The creature’s attention shifted back toward the pipe as soon as they were clear.
Iven held his position.
The foreman stared at him. “Why isn’t it coming after you?”
“Ask it.”
Kesh edged along the wall toward the tool rack. “It changed direction when the rack moved.”
“Or when the man moved,” Sera said.
“Or when I stepped closer,” Iven added. “We’ve got choices.”
The creature struck the loose bracket again. A bolt dropped and rolled across the floor. The pipe jerked against the remaining support, harder this time.
“That bracket goes, the pipe tears loose,” the foreman said.
She took a wrench from her belt. Iven caught her sleeve before she could advance.
“We can do it,” he said. “Not while it’s standing under the pipe.”
The creature pressed its jaw against the mounting. It did not appear to be trying to eat the steel. It scraped at the edge where the plate met the wall, tearing away a thin strip of material. A dark fluid welled out and ran down behind the bracket.
Sera’s expression changed. She did not announce a conclusion. She simply watched the fluid and the creature’s broken shoulder.
Kesh looked toward the drill. “If we move the guard away from the pipe, it might follow.”
“Or attack the person moving it,” Iven said.
“I’m aware.”
She picked up a long rod from the rack and hooked the torn guard. The creature’s head rose. Kesh drew the guard across the grating, producing a harsh scrape.
The creature came after it.
Iven moved with Kesh, keeping between the creature and the workers. She dragged the metal toward the far side of the chamber, away from the pipe. The creature followed for three steps, then stopped. Its head turned back toward the vibration.
“Not enough,” Kesh said.
The pipe knocked again. The creature ran beneath it, and the foreman swore.
Iven looked at the remaining bracket and the open space above it. He could reach the mounting from the opposite side if someone kept the creature from lunging at him. The job required a new fastener, a wedge, and a hand steady enough to work while the pipe moved.
“I need two minutes,” he said.
“You’ll get one if it decides it doesn’t like you,” the foreman replied.
“Then don’t waste any of it.”
She produced a bolt and wedge from her belt pouch. Kesh took a position near the opening with the torn guard on her rod. Sera moved the injured worker farther back and told another to keep the path clear. The foreman took the drill’s hand wheel and turned it until the cutting arm was well away from the wall.
Iven crossed to the pipe. The creature watched him. He kept his movement slow until he reached the bracket, then set a small brace between his forearm and the mounting to keep the pipe from striking his hand.
It lunged.
Kesh slapped the torn guard against the grating. The creature twisted toward the noise. Iven seized the moment to push the wedge into the bracket. The pipe kicked against it. He tightened the bolt one turn, then another.
The creature came back. Its broken shoulder hit the brace. Iven felt the impact in his elbow. He drove a piston strike into the side of its head, not hard enough to break the armor but enough to turn it. Kesh pulled the guard again. This time the creature followed for a full body length.
The foreman reached around Iven and held the wedge while he tightened the bolt. The bracket pulled snug against the mounting. The pipe still vibrated, but it no longer struck the plate.
The creature stopped. It stood with its head low, facing the wall. For a moment no one moved.
Then a second creature appeared in the opening.
It was smaller, as the injured worker had said, but its legs were longer in proportion to its body. It crossed directly toward the dark fluid beneath the mounting. The first creature gave a short, rasping sound. The second did not retreat. It began scraping at the damaged edge of the plate.
“It’s still coming,” the foreman said.
“Yes,” Kesh replied. “The drill stopped. The pipe’s quieter. Something is still damaged.”
“That doesn’t prove why it’s here,” Sera said.
“No. It doesn’t.”
Iven backed away from the bracket. He had done the immediate repair, but he did not want to discover whether the second creature would treat his retreat as an invitation. The first followed him two steps, then turned toward the opening.
The foreman took a whistle from her pocket and blew one short note. The workers filed out through the door in the order they had practiced for a pipe failure. Iven went last with Kesh. The two creatures remained beside the mounting.
At the bend in the passage, the foreman leaned against the wall and let out a breath. “I have a schedule. If I don’t finish that mount, someone else will send another crew.”
“You’ve got a reason not to restart yet,” Sera said. “I’ll write what I saw.”
“You’re an expelled doctor.”
“Still able to write.”
The foreman gave her a sharp look, then smiled despite herself. “I need someone they’ll listen to.”
“Elian can record the location,” Iven said. “Neri can look at a mounting that doesn’t cut farther into the wall. And I can ask the valve room for a proper reduction.”
“You think they’ll give you one?”
“No. I think they’ll have to tell me why they won’t.”
Kesh wrapped the torn guard in canvas. “I want to come back when the pipe is quieter and the mounting is covered. Not to prove the creatures are harmless. To see what changes.”
The foreman rubbed the bridge of her nose. “One test. With a way out.”
“Agreed,” Kesh said.
Sera glanced back down the passage. “And no one touches the tissue until we know how to do it without making the wound larger.”
“Agreed to that too,” the foreman said. “Can we go somewhere I can’t hear the pipe?”
They climbed toward the occupied decks. The vibration faded gradually, replaced by the clatter of carts and the ordinary voices of people going about a day that had already contained more than one disaster. Iven’s left forearm felt warm from the brace and strikes, but his hand was steady. He flexed his fingers once and followed the foreman into the light.
Above them, Mercy continued to walk. Below them, something had come to a damaged wall and refused to leave simply because a human machine had stopped.