The first flakes hit the glass case and stuck.
JJ looked down at the white smears spreading under her hands. The powder had climbed through the vents dry, but the case had warmed enough to turn it tacky. Each burst from below slapped more of it against the runners, the hinges, and the small guide teeth along the track.
"That is paste now, nowhere near dust anymore," JJ said. "It is packing itself into every rail tooth."
Blue kept Daemon’s dead fuse pinned in the cut and shifted her weight away from the nearest vent.
"It was track stabilizer before the fire woke it up," she said. "Now it is hot paste with bone grit inside it."
"I liked dust better than hot paste with bone grit inside it," JJ said.
Rusuf kept both hands on the maintenance sword beneath the stone lip. Heat had reddened his palm around the grip. He changed nothing. The buried body’s wrist ring sat half a finger from the loose hook, and Yun-Jin still had the hook dragged back with the folded cloth.
The fire channel under the bridge punched again.
White powder shot up through the rail slots and hit Ty’s ribs. It hurt differently from a blade. It clung. Fine grains caught in every crack along his chest and shoulder, then hardened as the heat breathed over them. His left arm dragged lower by a small weight that should have meant nothing.
In this room, small weights became verdicts before anyone noticed.
Ty brushed the powder from his ribs with the back of his wrist. Half of it came away. The rest stayed inside the cracks and pulled when he moved.
"The grit is setting wherever the heat touches," he said.
Blue glanced at him once, then back to the fuse.
"Keep it from sealing your joints and hinges," she said. "If it packs inside a hinge, I may have to break clean bone to free you."
JJ tightened her grip on the case frame.
"Nobody gets to call any part of this clean," she said. "The case is already grinding itself sideways under me."
The case shifted under her hands and bit against the guide.
It moved a little, still short of falling.
Enough for the right runner to climb over a clot of white paste and land crooked. The glass body inside slid one finger against the panel, slow and patient. The sound came through the frame as a dull scrape that made JJ bare her teeth.
"It is using the lift to steer itself," she said.
Ty saw it then. The case had moved because the rising paste raised one side, and the body inside had leaned into that uneven lift. If the next burst packed higher under the right runner, the case would twist off the guide.
The receiver tray answered with a low rattle underneath.
The two sickles above the board opened another finger width. Their hooked ends turned toward the case track, then away, then back again. They could hear the fire line. They could hear the return path. The bone powder gave them nothing clean to cut.
"The sickles are not finding a line through the powder," Ty said.
"Powder does not sign its name before it ruins the bridge," Yun-Jin said.
JJ shot her a look without letting go of the case.
"That sounded too much like something this place would consider a challenge."
Blue pressed the fuse harder into Daemon’s cut. The ceramic scraped under the cloth and sent one thin white spark across the board.
"Keep the sickles open while the fuse holds," Blue said. "If the track jumps and the bodies reconnect through the hook, they must be ready."
The next vent opened under JJ’s left foot.
Ty moved before he had a clean plan. He hooked one arm around JJ’s waist and pulled her sideways against the case rather than away from it. The white burst hit the floor where her boot had been and built a lump the size of his fist against the runner.
JJ slammed her shoulder into the case frame.
The glass shuddered but stayed in the guide.
"Warn me before using my spine as equipment," she said through clenched teeth.
"Your boot was about to become part of the bridge," Ty said.
"That is almost a real apology, but uglier."
Yun-Jin’s cloth slipped around the hook. The copper edge kissed the wrist ring under the stone lip.
The board under the fuse clicked twice, hard and dry.
Rusuf drove the sword grip down with both hands and lifted the lip just enough to break contact. His burned palm left skin on the wrapped handle. His face went flat with pain, but the hook rose away from the ring.
Blue’s mouth tightened around whatever warning she swallowed.
"Rusuf, your hand is losing useful grip quality," she said.
"The hand has complaints, but it remains employed."
"Employment ends if the grip fails near the ring," Blue said.
"Then give me useful work before my hand resigns," Rusuf said.
Ty looked beyond the bridge rail for something solid.
The fire vents ran in pairs along both sides of the case track. Between each pair sat old rectangular blocks sunk into the support seam. Freight bricks, blackened by age and heat, each one slotted into a shallow cradle. Several had already loosened when the stabilizer deposits broke apart.
The nearest loose brick sat under the left rail, half lifted by paste.
Ty reached for it with his bare skeletal hand.
"Do not grab the hot brick with bone fingers," Blue said.
He stopped with his hand over the block.
JJ twisted just enough to see what he had found.
"Can we use those to cap the vents?" she asked.
"Capping them would only push pressure under the track," Blue said. "If we seal the vents, pressure lifts the track from below."
"Then what does a useful answer sound like?" JJ asked.
Blue looked at the paired vents, the runner, and the spreading paste.
"Weight the paste before it climbs higher again," she said. "Leave narrow exits that aim toward the outside rail."
"So we are building gutters in a fire made of powdered dead track," JJ said.
"You asked for the useful version, not the pleasant one."
The case lurched again and scraped the guide teeth.
This time the right runner climbed higher. JJ slid with it and nearly lost her shoulder hold. Ty braced his hip against the frame, but powder had hardened around his left knee. His leg answered a fraction late.
The case tilted toward the buried body under the stone.
Yun-Jin dug her heels into the bridge and hauled the hook back with both hands. The cloth smoked at the edge. Her jaw clenched so hard the tendons in her neck stood out.
"I need that track level before my cloth burns through," she said.
Rusuf looked at the loose brick and then at his own trapped hands.
"I cannot move the brick while holding the lip," he said.
JJ shifted her grip along the case frame.
"I cannot leave the case unless everyone wants the body to steer."
Blue kept one hand on the fuse and the other on the board edge.
"I cannot let the fuse rise while the sickles are listening," she said.
Ty looked at his powder crusted knee, then at the nearest brick.
Every trapped hand left Ty as the only mover.
The sickles still hovered over Daemon’s cut. If he moved too far, they might close or chase the wrong sound. If he stayed, the paste would build under the runner until the case turned.
He needed reach more than strength in that spot.
The service pin lay near the tray edge where JJ had left it. Thin, dark, and still warm from the board. Ty picked it up and slid it through the hole in the nearest loose brick.
The pin bent before the brick even shifted.
Ty changed angle and pulled low, toward the outside rail. The brick dragged an inch through paste. Hot grit caught against the underside and made the pin tremble in his hand.
His fingers slipped against the paste crusted metal.
Bone powder had sealed between two of his knuckles.
Ty pressed the pin against the brick again and drove the pull through his wrist. The joint scraped. The hardened grit cracked inside his hand. He kept pulling until the brick slid free of its cradle and dropped across the first vent mouth at an angle.
The next burst hit the brick squarely from below.
Powder slammed against the block, split around both sides, and spilled outward before it reached the runner. The pressure still climbed, but lower. The case settled by the width of a coin.
JJ shoved with her shoulder and got the runner back into its tooth.
"That helped more than I expected it to," she said. "I am angry that it helped so little."
"It helped enough that we repeat the method," Blue said.
Ty flexed his hand. Two fingers answered badly. One answered only after he knocked the joint against his thigh and cracked the paste loose.
The sickles above the board twitched toward him.
The movement felt less like warning than attention.
The board had felt the brick change the path. The sickles had heard the pressure move around a crude weight rather than through a living claim. That mattered. The room had offered a way through without another body paying.
Ty looked along the rail and counted the pairs.
There were more bricks, some loose, some still seated, and each one sat between a pair of vents. The paste was climbing faster than he could clear by hand. The fire under the bridge kept punching, patient and regular, and every burst brought more bone grit into the guide.
JJ followed his gaze along the damaged track.
"You are about to say something that makes this worse," she said.
"The track is a row of small failures," Ty said. "Each one is reaching the case from below."
Yun-Jin coughed once into her shoulder and pulled the hook another finger away from the wrist ring.
"Then solve the nearest small failure before it becomes the large one," she said.
Rusuf tightened his ruined grip around the sword.
"Give me the order while I can still hold the lip," he said.
Ty set the bent service pin into the next brick hole and felt the hardened powder grind inside his palm.
"We move the bricks one at a time," he said. "Nobody lets the case choose direction while I work."