The corridor after the steel gate had been built for heat and bad footing.
The west rail ran down its center through a shallow trough. Warm air pushed from vents along the floor and carried the smell of old fat from the jar in Blue’s hands. The walls were close enough that JJ had to turn her shoulders sideways when she moved beside the case.
"This corridor is slick before we add anything to it," JJ said. "I dislike places that prepare their own accidents."
Blue hugged the ceramic jar against her chest.
"The buttered mess got us through the gate," she said. "I am giving it a respectful period before I insult it again."
Balisk pushed from behind for three more feet, then the force left the rail.
The case rolled under its own weight after that. The worker rail sloped down just enough to keep it moving. Its wheels rode the track with a dry scrape that set Ty’s teeth on edge. The old body inside stayed low in the glass, palm turned toward the direction of travel.
Ty walked beside the claimant side with his palm near the rail.
His marked hand still felt connected to the transfer, although the claimant iron was behind him now. The feeling came through pressure rather than pain. When the case scraped, his palm prickled. When it rolled cleanly, the mark cooled.
"The case is dragging along the right rail, and it feels dry under my hand," Ty said.
"Your hand now reports railway maintenance, and that is new and unwelcome," JJ said.
"I preferred when my hands only made bad decisions," Ty said.
Blue lowered the jar and looked at the rail trough.
The dry scrape came from the right guide shoe under the case. The shoe was black metal, worn flat along one edge. It had a small feed groove above it, the kind a worker could fill while the load moved if the worker enjoyed risking fingers.
"The right shoe needs fat under the case," Blue said. "The gate used the jar because the rail expects it."
"How much fat keeps the case moving without making it run away?" JJ asked.
Blue opened the jar and looked inside under the heat.
"Less than panic says and more than dignity allows," she said. "Ty, report the scrape while I feed the groove."
Ty nodded and kept his marked palm near the side rail.
Blue scooped old fat with Marcus’s bit. The stuff had softened from the corridor heat. It clung to the tool in yellow-gray layers with dark herbs or grit suspended inside it. Blue made a face, then worked the bit toward the feed groove.
JJ walked ahead of the case with her sword low.
"If this becomes a kitchen ritual, I am retiring from wall machinery," JJ said.
"You retired from wall machinery three rooms ago," Blue said. "The wall declined your resignation again without appeal."
The first smear of fat touched the guide shoe.
The scrape eased under the first smear of fat.
Ty felt the difference through his palm at once. The mark cooled under his skin. The case rolled smoother, quieter, less angry against the track. Blue fed a second smear into the groove, and the right shoe stopped biting.
"That helped, and the rail feels cleaner now," Ty said.
"Never say cleaner while I am holding old butter from a wall jar," Blue said.
The case picked up speed down the slope.
Not much at first. One inch, then another, then enough that JJ had to lengthen her stride. The corridor sloped down harder after the first bend. The rail trough narrowed, and the walls reflected the wheel sound back at them.
"Blue, your respectful butter has ambition already too," JJ said.
"That means I used too much, and I blame the emergency," Blue said.
Ty moved closer to the side rail and pressed his marked palm flat against it.
"Claimant reports fast load, worker rail greased, load sealed, slow if available," he said.
The rail answered with a click under the trough.
The case slowed by a fraction, then kept rolling.
"It heard you, but the slope is arguing," Blue said.
"The slope can stand in line behind us," JJ said.
She moved ahead and put her sword across the front guide, flat to the case frame. Ty reached for her sleeve, then stopped himself before his hand left the rail.
"Do not brace with your body in front of it," he said. "The case has more votes than your knees."
"I am using the sword as a brake, not my knees," JJ said. "I have learned at least one thing today."
The blade touched the front guide and held.
The case pushed into it. JJ slid backward, boots dragging through old fat on the floor. Ty kept his hand on the rail and reported the pressure while Blue ran beside the right guide shoe with the jar open.
"Pressure rising at the front, worker lock still warm, old body still low," Ty said.
"Good report, bad situation from here for us," Blue said.
She jammed Marcus’s bit into a small side hole above the right shoe.
The hole took the bit and turned. A scraper dropped from beneath the case, dragging against the greased rail. The extra fat peeled away in thick ribbons and fell into the trough. The case slowed enough for JJ to stop sliding.
"The rail had a scraper underneath for this," Blue said. "Stelia’s people thought of the butter problem before us."
"Stelia’s people probably caused the butter problem before us," JJ said.
The scraper held for six yards under load.
Then the trough widened around a heat vent.
The rail split into two parallel lines around a central heat vent. The case shifted toward the right line, pulled by the greased shoe. Ty’s marked palm warmed sharply. The old body’s shoulder rolled inside the glass, and its hand pressed toward the right wall.
"Right rail is pulling the case, and the body is leaning with it," Ty said.
Blue looked ahead toward the vents past the case.
The right line ran past a row of round vents. Each vent had a metal cover with fan-shaped slots. None of the fans moved, but air came through them in steady pulses. The left line stayed dry and straight. The right line looked polished by use.
"Right rail is the butter line for greased loads," Blue said. "That is where loads go when the shoe gets fed."
"Does butter line sound safe in any language?" JJ asked.
"It sounds maintained, and safe is an emotional request," Blue said.
The rail fork had no lever nearby for them.
The case continued drifting right despite Ty’s report.
Ty pressed harder against the side rail and felt the claimant mark pulse back. The mark understood load and motion, not preference. It could report trouble, but the rail had already chosen what it considered a solution.
"Claimant reports unwanted right line, load sealed, worker lock warm, request left rail," Ty said.
The rail clicked once under the trough below.
Nothing shifted under the case or rail afterward.
The case drifted another inch right toward the vents.
"Request denied by butter again from here apparently," Blue said. "I hate that sentence and the physics behind it."
JJ glanced over the case at the shoe.
"Can we scrape the right shoe again before the fork?" she asked.
Blue tried the side hole with Marcus’s bit.
Marcus’s bit turned once and stopped. The scraper under the case had reached the fork and lifted away. The mechanism expected the greased load to choose the butter line. It had no interest in arguing after that.
"Scraper is out, and we need weight left," Blue said.
Ty looked at the old body in the case.
The hand inside pressed toward the right wall, but the skull had turned slightly left. The body wanted the gate earlier. Here, it seemed split between the greased rail and something beyond the dry line. He felt both directions in the claimant mark, a dull pull right and a thinner tug left.
"The old body is split, hand right, head left," Ty said.
"That is horrible information from him right now," JJ said. "Can it pick one like a polite corpse?"
"No ownership language, remember for the body please," Blue said.
"Fine, can the sealed old body with unresolved manners pick one?" JJ asked.
Ty almost laughed, which would have been a waste of breath.
"The left tug is weaker, and it feels like signal under grease," he said.
Blue looked at the jar in her hands.
"Then we buttered the loud path by accident," she said. "The dry path may be correct because it is quieter."
"I am beginning to resent every correct thing being harder," JJ said.
They needed weight left before the fork finished.
JJ moved to the left side of the case and hooked her sword under the frame, flat edge against metal. Ty kept his marked palm on the side rail and leaned left without touching glass. Blue dropped the jar into the trough, wiped her hands on her coat, and grabbed the rear guide.
"On my count, we pull left without tipping the case," JJ said.
"Counting assumes confidence I lack right now badly," Blue said.
"Borrow mine, it is mostly anger today anyway," JJ said.
They pulled against the greased right shoe together.
The case fought them through the greased right shoe.
Ty felt the right pull drag at his palm. His shoulder burned under the bandage. JJ’s sword creaked against the frame. Blue’s boots slipped, caught, slipped again. The case moved left by half an inch and tried to take it back.
"Claimant reports left correction, load sealed, worker lock warm, left rail has living pull," Ty said.
The rail clicked under his hand in answer.
This time the left line rose under the load.
The case bumped across the fork and dropped onto the dry rail with a hard jolt. Everyone stumbled with it. Blue nearly fell into the trough, caught the jar by its rim, and kicked the greased right line as if it had personally offended her.
"Left rail accepted living pull, and right rail can go be slippery alone," Ty said.
"That was almost elegant, and I refuse to say which part," JJ said.
The dry line carried them through the fork.
The corridor narrowed again, then opened into a round chamber where the heat changed direction. Air moved across them from ahead rather than below. The sound came first as a low chopping rhythm, slow and steady, metal blades cutting air somewhere beyond the next door.
Blue wiped fat from Marcus’s bit and held it ready.
"Those are fans, big ones from the sound," she said.
JJ looked at the jar in Blue’s other hand.
"Please tell me the next room does not require us to butter a fan," she said.
The door ahead had a worker sign bolted crooked above it.
The sign above the door read Fan fair.
Behind the door, the blades turned faster inside.