Elian returned the next morning with three maps and a complaint.
“The office wants the cup.”
Brin, who was polishing the cup’s unpainted side with a cloth, drew it closer. “They can’t have it.”
“They haven’t asked you.”
“They will.”
Iven took the cup from him before the blue bird lost its tail. “What does the office want it for?”
“To determine its origin.” Elian laid the maps on Sera’s table. “They also want my notes.”
“Do they know where you found it?” Sera asked.
“I reported an undocumented room. I didn’t give them the route.”
“Why not?”
Elian looked at the cup. “Because the first person I showed it to asked who had authorized me to bring it out, rather than whether there were people in the room.”
“There weren’t people in the room,” Brin said.
“There had been.”
The maps covered the same part of Mercy at different times. The newest showed a solid internal support where the room lay. The oldest showed a ventilation route that stopped near it. On the middle map, a patch of paper had been pasted over the same area.
Neri held it to the light. “Can you read what’s underneath?”
“Not without lifting the patch.”
“Can you lift it?”
“Not if the office intends to take the map back.”
Sera examined the edge. “It’s ordinary paste. Steam might loosen it.”
Elian pulled the map away. “It could also damage the ink.”
“Then we don’t steam it,” Iven said.
Brin looked disappointed. “I could hold it over the kettle.”
“You could,” Sera said. “You won’t.”
Kesh came in carrying a bundle of narrow wooden stakes. She set them against the wall and unwrapped the point of her spear. A small notch had appeared near its tip.
“The creature left the corridor,” she said. “I checked the cut. The cloth is still there.”
“How do you know it left?” Iven asked.
“I followed its tracks to the lower drainage channel. The dust there keeps a good impression.”
“Can it come back?”
“Yes.”
“Good. I didn’t want the morning to become too comfortable.”
They returned with additional rope, a flat board to spread weight across the old floor, and a covered basket for any loose objects they chose to remove. Tavin had arranged a watch at the entrance to the maintenance passage. His crew knew only that a survey was being conducted. They also knew how to stop curious people from wandering into a place where the floor had not been checked.
At the old door, the cloth Sera had tied over the cut was damp but intact. Pale material had begun to gather at its edges. She touched it with a gloved finger, then examined the glove.
“I want to compare this with the sample from yesterday.”
“Is it dangerous?” Brin asked.
“Everything in a body can be dangerous in the wrong place. That’s not the same as knowing this is.”
Neri checked the frame. The upper hinge had sagged slightly since their visit. She wedged it in place before Iven eased the door open. The room beyond looked unchanged: the table, the shelf, the little windowless curve of wall. The space where the cup had lain seemed conspicuous now.
“It’s strange,” Brin said. “It feels as though someone should come back for it.”
“Someone did,” Iven said. “You.”
Brin looked pleased until Sera reminded him that he had removed it without permission.
Elian made a careful drawing of the first room. Iven and Neri went through the second door with the flat board, laying it across the weakest section of floor. The corridor beyond had five doorways. Two were blocked by collapsed shelves. One led to a room with a stone basin and a drain. Another opened on a narrow chamber with hooks along the wall, three of them still holding scraps of cloth.
The fifth door had been painted green. Most of the paint remained on the lower half, where mineral growth had protected it from damp.
Iven pushed it gently. The door swung inward.
The room held two beds built into opposite walls. One was adult-sized. The other was shorter, with a carved rail to prevent a child from rolling out. A piece of red thread hung from the rail. Under the smaller bed lay a wooden animal with one wheel missing.
Brin stopped behind Iven. “Can I look?”
“Watch the floor.”
He stepped past them and knelt beside the toy. The animal had been carved from a single piece of wood, with a broad back and a rounded head. Its remaining wheel was fixed through a hole in its side. Brin turned it over without lifting it.
“It looks like Mercy.”
“It looks like a loaf with legs,” Neri said.
“Mercy looks like a loaf with legs.”
“From a great distance.”
Iven crouched beside the toy. Its missing wheel had left an empty axle hole. He could repair it with a bit of wood and a pin, but the urge felt intrusive. The toy had survived here by being left alone. A repair could wait until someone decided whether it should be moved at all.
Elian entered with his notebook. He wrote down the beds, the hooks, the basin, and the toy’s position. Then he stopped writing.
“What?” Neri asked.
“If these rooms were occupied, the survey should have recorded them.”
“How old is the oldest survey?”
“The copy I brought is a hundred and forty years old.”
“Then the rooms may be older.”
“They may.” He looked at the carved rail. “I wish the map said that instead of saying solid support.”
Sera ran her hand a short distance above the wall without touching it. The pale material behind the wood showed through a gap in the boards. She took a clean probe from her case and pressed it against the exposed surface. The probe came away damp.
“Is it bone?” Iven asked.
“It has a hard outer layer. I won’t call it bone until I know more.”
“Everyone calls these passages bone hollows,” Tavin said from the doorway.
“Everyone can continue doing that. I’m asking a different question.”
A faint tapping came through the wall. Brin straightened. Kesh, stationed at the corridor entrance, listened with her head tilted.
“Not the same sound as yesterday,” she said. “Farther away.”
Neri examined the bed supports. The adult bed had been fastened to a wooden frame that flexed slightly when she put her weight on it. The shorter bed used a different arrangement: a sliding joint with a stop at either end.
“They expected the room to move,” she said.
“Everything on Mercy moves,” Iven replied.
“Not everything is built to admit it.” She pulled the joint gently. It shifted and returned. “This was.”
Elian sketched the joint. Iven looked at the walls again, noticing small gaps where boards met the curved structure. A strip of woven material filled each gap. The room had not simply been carved into a hard surface. It had been designed to accommodate changes around it.
Sera found a second patch of tile in the corridor, mostly hidden behind a fallen shelf. Blue, white, and a dull red showed beneath the dust. Iven helped Neri lift the shelf away. They set it against the opposite wall, careful not to disturb the tiles.
The image was incomplete. A curve of pale pieces crossed the lower section. Above it were several darker shapes, too damaged to identify. A line of tiny blue tiles ran between them.
“A map?” Elian suggested.
“A border,” Neri said.
“A very small river,” Brin offered.
Iven leaned closer. One of the darker shapes had four square tiles arranged like legs. It might have been a person, an animal, or a pattern created by missing pieces.
“We need more of it exposed,” Sera said.
“Not today,” Kesh called from the doorway.
The tapping had grown louder. It came in short sequences, interrupted by a low scraping sound. Kesh moved back into the corridor, spear held across her body. A pale limb appeared through the crack by the entrance door, followed by a second.
“It’s larger than the one yesterday,” she said.
Iven joined her. The creature forced its head through the gap, plates scraping the frame. It was indeed larger, with a blunt ridge over its eyes and a broken piece of armor on one shoulder. It stopped when it saw the people in the corridor.
Neri guided Brin and Elian back toward the green room. Tavin stood beside Iven with a length of rope. Sera closed her case and moved behind them, though her attention stayed fixed on the creature’s damaged shoulder.
“Can it fit through?” Tavin asked.
“I don’t know,” Kesh said.
The creature pushed. The doorframe cracked. Iven set a plate brace against the lower part of the frame, spreading the force across the wood and the hard wall beside it. The brace held, but the creature did not stop. It drove forward again, dragging its shoulder against the opening.
“Why?” Brin whispered.
Iven had no answer. The room contained people, damaged wall, old wood, and several sounds. He could not tell which of those mattered to the creature.
Kesh struck the floor with her spear. The creature’s head turned toward the sound, but its body continued pressing against the door.
“It’s not following that,” she said.
“Can we get out the other way?” Neri asked.
Elian pointed to the far end of the corridor on his sketch. “There may be a service connection beyond the basin.”
“May?”
“The wall curves toward the drainage line. I haven’t seen it.”
Tavin took the rope. “I’ll look.”
He went through the basin room with Brin holding the lamp. They found a low opening behind a panel, partly blocked by collapsed shelves. It led toward the drainage channel Kesh had followed earlier.
“We can clear it,” Tavin called.
The creature pushed again. The doorframe split from top to bottom. Iven’s brace shifted with it, and pain flashed through his left forearm as he adjusted the force. He could hold the frame for a short time; he could not make it into a wall.
Neri and Elian hauled the fallen shelf away from the opening. Sera passed her case through first, then helped Brin crawl after it. Tavin followed, pulling the rope behind him.
Kesh stayed with Iven. “When you release it, step toward the table. I’ll draw it away.”
“With the spear?”
“With the lamp.”
She swung the lamp low, casting light across the opposite wall. The creature’s head followed the movement. Iven released the brace and stepped sideways. The frame burst inward. The creature entered the room, knocked the table onto its side, and turned toward the moving light.
Kesh backed through the basin room. Iven followed, keeping the creature in sight. It struck the table again, sending dust into the air, then paused at the damaged hinge. Its forelimb touched the exposed pale material beneath the broken wood.
“Now,” Kesh said.
They crawled through the service opening. Tavin pulled the shelf back across it from the other side, not sealing it completely but making a barrier. The drainage passage beyond was narrow and damp. Water ran around their boots as they followed it toward a ladder.
At the top, they emerged into a small pump room two levels below Sera’s workshop. The pump keeper stared at them as though a collection of wet ghosts had climbed out of his floor.
“Is that drain open?” he asked.
“It is now,” Tavin said.
The keeper looked down the ladder. “I put a cover on it last week.”
“Your cover did a fine job,” Iven said. “It kept us from coming up somewhere else.”
Sera set her case on a bench. Elian unfolded his damp sketch and checked the lines. Brin still had the red thread from the child’s bed looped around his finger; he had not taken the toy.
Neri examined the rope for damage. “We need a better route if we’re going back.”
“We are going back?” Brin asked.
“We haven’t finished recording the rooms.”
Sera touched the packet containing the pale material. “And I want to know why the creature went to that door.”
Kesh looked at her spear’s chipped point. “So do I.”
Elian spread the map on the pump keeper’s cleanest table. The service opening they had used connected to a drain marked on the old survey, but the rooms themselves still lay inside the solid block.
“Someone changed this,” he said.
“Or someone drew it wrong,” Iven replied.
Elian’s finger rested on the pasted patch in the middle map. “Then tomorrow I’ll ask why the correction was pasted over instead of drawn in.”