The drying room smelled like a wet coat left in a cupboard for a year.
Iven stood in the doorway while the workers lifted a sheet of filter cloth from its frame. Water ran from the bottom edge into a trough. The cloth should have dried overnight in the warm air from the lower fan. Instead it remained heavy enough that two people needed to carry it.
“This is the third batch,” the forewoman said. “The clinic has enough clean dressings for today. The filter crew has enough cloth for two days.”
“Can you hang it outside?” Iven asked.
“In the rain?”
“Under the freight roof.”
“The freight roof is full of people whose rooms fell down.”
He looked at the rows of damp cloth. The problem was no longer a stopped machine in a tunnel. It was the work that stopped with it, spreading outward through a city that had already lost too many rooms and too many hours.
The forewoman introduced herself as Dema. She had a long wooden pointer tucked through her belt and used it to show them the air route. The lower fan drew air from a warm channel, passed it through a dust screen, and pushed it along a duct beneath the drying frames. A second vent near the ceiling carried moist air out.
“We can warm the room with a stove,” she said, “but without the fan the air stays wet. We tried opening both doors. The dust came in faster than the cloth dried.”
Neri examined the upper vent. Its cover moved when she pushed it, but the lower hinge had seized. “Can we use a temporary screen?”
“We can. It won’t give us enough flow for all the frames.”
“Enough for some is better than none.”
Dema pointed to the frames nearest the door. “Those first. The clinic’s cloth goes there.”
Iven helped Jem fit a clean screen over the doorway. Dessa moved the wettest frames farther back while the workers carried the clinic’s batch into the path of the draft. The result was modest. The cloth moved, which it had not done before. Dema held a strip of paper near the screen and watched it lift.
“That buys us a few hours,” she said.
“Can you rotate the frames?” Neri asked.
“Every hour. The workers will hate me.”
“They can take turns.”
“They’ll still hate me.”
A cry came from the passage outside. Brin appeared at the door, his coat wet and his breath short.
“Kesh says the lower duct is open,” he told Iven. “One of the young vent-hooks came out near the channel. It didn’t go back.”
“Where did it go?”
“Toward the service stair.”
“Anyone hurt?”
“Not yet. Kesh sent me to clear the stair.”
Iven took his spanner and followed him. Neri sent Dessa to keep people out of the lower passage and remained with Dema to secure the drying room’s temporary screen. Jem came after Iven with a length of rope and a lamp.
At the stair, a small crowd had gathered behind Kesh. She held her hooked pole across the entrance. The passage beyond her was empty, but a scraping sound moved through the wall to the right.
“There’s another route behind the duct,” she said. “It came through a panel and climbed into the wall.”
“Can it get into the drying room?”
“Possibly. The wall connects to the vent housing.”
Iven looked at the crowd. Two workers carried bundles of cloth. A child held a basket of pegs. If the creature emerged among them, the narrow stair would become a trap.
“Up to the landing,” he told them. “Keep the center clear.”
They moved reluctantly. The child dropped the basket, scattering pegs across the steps. Jem helped collect them while Iven listened to the scraping. It had stopped.
“That worries me more,” Brin said.
“Me too.”
Kesh pointed to a small inspection cover near the floor. Its bolts had been loosened. A dark gap showed at the lower edge.
“Can we close it?”
“Not without getting close.”
“I’m aware.”
Iven seated plate brace, piston strike, and bell pulse. The hook and winch were in the library, but the passage was short and the threat close. He crouched beside the cover while Kesh stood at an angle where she could reach the gap without putting the pole across his face.
He put his hand on the cover. The metal was warm. Something struck it from the other side.
The impact drove the cover against his fingers. He pulled them clear before it struck again. The lower bolt fell out and rolled down the stair.
“It’s trying to open it,” Brin said.
“Or it’s trying to get away from the noise on the other side,” Kesh replied.
“Can we ask it?”
“Not safely.”
Iven picked up the bolt and fitted it into the lower hole. The threads caught, but the cover bulged again before he could tighten it. A hooked limb appeared through the gap.
He raised the brace. The limb struck it, scraping across the invisible surface. Kesh caught the hook with her pole and held it away from the workers. Iven drove the bolt with his right hand until the cover sat against the frame.
The creature pulled. Kesh released the pole before it could drag her into the gap. The hook withdrew. Iven tightened the second bolt and checked the upper edge.
The scraping moved away along the wall.
“That keeps it out of this stair,” he said. “It may find another opening.”
Kesh marked the cover with chalk. “I’ll watch the lower route. You need the fan.”
They descended to the service junction with Jem and two workers from the drying room. The repaired bridge from yesterday held under the temporary supports. The lowered pipe still lay across one side, leaving a narrow path beside it. Iven tested the boards before stepping onto them.
At the fan housing, Vela had already removed the outer screen. The wheel inside was a large metal drum fitted with angled blades. Three blades were bent, and the central shaft had shifted in its bearing. The broken bone had lodged in a gap between the drum and the housing, stopping the rotation.
“Can you straighten them?” Vela asked.
“Two. The third has a crack at the root.”
“We have a spare plate.”
“Not the whole blade?”
“No.”
Neri arrived with the measurements from the drying room. She checked the fan drum, then the duct leading upward. “If we restore this, the air goes straight to the frames?”
“Through the screen and the lower channel,” Vela said. “Unless something is blocking the channel.”
Iven looked toward the duct where the vent-hooks had entered. “We need to check it before we start.”
They opened the lower access panel. Inside lay feathers, wire, and pieces of cloth packed around the bend. A small carcass rested against the far side. Kesh had been right about the predators using the duct as a route.
Jem took a hook and pulled the debris out. The smell was worse than the drying room. Brin held the lamp and tried not to breathe through his nose. He succeeded for almost a minute.
“I’ve had better jobs,” he said.
“You said that while carrying soup,” Iven replied.
“The soup didn’t smell like this.”
They worked until the channel was clear. The carcass went into a sealed sack for Kesh. The wire was set aside separately, because one end carried the same clean cut as the piece found in the kite nest. Someone had been fastening things in the duct, or the predators had been carrying material from a place where wire was cut. Neither possibility could be settled by staring at the pile.
Vela showed Iven the spare plate. It was large enough to replace the cracked blade but too thick to fit the drum’s original mounting. He measured the old blade, then the plate, and marked a section that could be shaped to match.
“We need the forge,” he said.
“The forge is on the upper deck.”
“Then we carry the plate up.”
Neri checked the drum’s shaft. The bearing had been damaged by the sudden stop but had not seized. She suggested replacing its worn sleeve while the drum was open. Iven agreed. They removed the drum together, using a physical hoist to take the weight. The old sleeve came out with a strip of metal worn bright along one side.
“There’s your noise,” Vela said.
“And the reason it will make a worse one if we put it back.”
They carried the cracked blade and spare plate to the upper forge. The smith there was busy making brackets for the collapsed lane. She listened to Dema’s list of damp cloth and clinic supplies, then moved one bracket aside.
“I can shape it this afternoon,” she said. “I can’t temper it until the furnace is at the right heat.”
“How long?”
“Longer if you keep asking.”
Iven accepted that answer and helped prepare the pattern. He laid the old blade on the plate, traced its curve, and marked the mounting holes. The smith checked the marks against the drum’s measurements. One hole was a fraction too close to the edge. She moved it and explained why.
“The old blade was riveted there,” Iven said.
“And it cracked there.”
He looked again. The crack had begun beside the old hole. The new position would leave more material around the fastening.
“Good change.”
“I’m glad you approve.”
They cut the plate and heated it. The smith shaped the curve over a rounded form while Iven held the other end with tongs. Sparks rose when the hammer struck. He watched the metal move, the curve gradually taking the shape needed to push air rather than simply occupy space.
When the blade cooled enough to measure, it was close but not exact. Iven filed one edge while the smith prepared the sleeve. Neri returned from the drying room with news that the temporary screen was helping, but the first batch would still be late.
“The clinic can use the cloth by evening if we finish the fan tomorrow morning,” she said.
“Then we’ll finish it tomorrow morning.”
She looked at the blade. “Is it ready?”
“Almost.”
“That’s not a condition.”
“It will be when we’ve tested it.”
The smith handed him the new bearing sleeve. He fitted it to the shaft outside the housing, turned the drum by hand, and felt it bind at one point. A small burr remained inside the sleeve. He removed it and tested again. The drum turned smoothly.
The work was not complete. The drum had to go back into the housing, the blade had to be secured, the duct had to be checked, and the fan had to move air under its own power. No new pattern settled in his graft merely because a piece had been shaped on a bench.
Kesh arrived before they left the forge. She had followed the wire to a storage recess near the upper channel. Inside were scraps of cloth, two stolen tools, and the missing fan blades from the upper station.
“The creatures were carrying shiny things,” she said.
“Why?” Brin asked.
“I don’t know. They may have used the wire to hold the nest together. They may have collected it because it was near the food.”
“Can we take the blades back?” Vela asked.
“Yes. The recess is empty now.”
Iven looked at the recovered blades. They belonged to the smaller upper fan, not the lower drum they were repairing. Two different machines had been affected by the same animals’ movements. The wire in the kite nest had led them to the vent; the vent had led them to the old plate; the plate had given Elian a place to investigate.
None of that made the predators harmless. The workers they had attacked were still at the clinic, and Kesh had seen two young ones disappear into a duct that connected to other passages.
“Can you keep people clear tonight?” Neri asked.
“I’ve arranged a watch. No one opens the lower hatch alone.”
Dema arrived with a basket of partially dried cloth. She held it up to Iven. “This is what we have for the clinic tonight.”
The cloth was usable, though not as dry as she wanted. Iven helped her carry it to Sera’s clinic. Sera checked the pieces and separated the clean ones from those that needed another pass through the drying room.
“Will the fan be ready?” she asked.
“Tomorrow morning.”
“That’s the same answer you gave Neri.”
“I’m trying to be consistent.”
Sera touched his shoulder. He winced before he could stop himself.
“You said you wouldn’t use it to catch a falling pipe.”
“I didn’t.”
“What did you use it for?”
“A creature.”
She looked at him for a long moment, then handed the basket to Brin. “Sit down.”
Iven sat. She examined the bruise and found no new injury, only the old one made louder by a day’s work. She told him to rest it overnight and return if the pain increased.
“Can I still repair the fan?”
“If you let the other five people lift the drum.”
“I was going to.”
“Good. I’ll ask them.”
Outside, the rain had stopped. The freight line carried Tavin’s message toward the Sill. Elian had copied the paired plates and marked the route through the vent. Iven had a blade cooling at the forge and a fan waiting below. For once, the things he wanted to do tomorrow depended on work already begun rather than a door he had yet to open.