The first grub fell short of the lamp and caught Lu Chen's coat instead.
Its hooked mouthparts closed on the loose sleeve. He tried to shake it off, but the creature's body folded around his forearm. The weight pulled him toward the water. Lu Chen struck the grate with his shoulder and drove the needle into its pale side.
The point skidded along a hard fold beneath the skin.
He stabbed again. Nothing gave. The grub hauled itself higher, dragging wet cloth through its jaws. Its head reached his wrist. Lu Chen cried out and struck it against the frame, once, then again. The iron bruised his own arm. The mouth stayed closed.
The second grub dropped onto the bank where the lamp had stood.
Lu Chen crouched, setting the lamp beyond his boot. He could not hold a light, fight the first creature, and keep the second away. His free hand caught the head clamped to his wrist. Under its jaw he felt a softer crease. He pushed the needle there and let a short thread of Qi run down the steel.
The point sank in. The grub tightened around his arm before loosening. Lu Chen tore his sleeve free, leaving cloth between its hooks. It fell onto the bank, still moving.
He stamped on the head. His boot slipped in slime, so he braced himself against the grate and pressed until the pale shell broke.
The other creature turned toward the lamp. Lu Chen took the scraper from his pouch and pushed beneath its body. It slid toward the water, caught the edge, and hauled itself back. He shoved again with both hands. The body dropped into the black run below. Water splashed over his boot and began eating the old leather.
He dragged the boot through mud to clear it. His wrist hurt with each movement. Two shallow punctures showed beside the coat's torn cuff. He wiped them with the inside of his shirt, retrieved the needle, and pulled the loose wire clear of the dead grub.
Something else moved along the roof.
He covered the lamp's flame. The hiss stopped when the wick went dark. Lu Chen stood in complete blackness with one hand on the grate. He waited, hearing water and the quick sound of his own breathing. Above him, the scraping gradually moved away.
He had seen them follow the light and its warmth. Extinguishing the lamp had helped. It had not made him safe. His body was still warm; his boots still disturbed the bank.
He drew a small amount of stored breath toward his eyes. The nearest bars appeared as dull shapes. When he tried to see further, pain gathered behind his brow and the shapes began to smear. He eased the flow until he could distinguish the stone beneath his feet.
That would have to do.
He wrapped his wrist and left the lamp tied inside the empty bucket sling he had brought with him. The bucket itself remained outside. With the flask under his vest and the scraper in hand, he followed the bank.
At the second grate, the same old hinge ears were buried under rust. He worked at the metal he had already learned to weaken. The cold made each opening of the stopper harder. He used less liquid, waited longer, and kept the flask closed while the iron softened. He could not hurry this part without spending the last of his way out.
The gate moved before both pins were fully free. Its weight dragged one ear downward, tearing it with a muffled scrape. Lu Chen held the edge against his hip and eased it onto a patch of moss. The strain opened the punctures at his wrist. He smelled the lamp oil on his sleeve and resisted lighting it.
Beyond the frame, the channel widened around a pit of churning runoff. The bank continued along the wall, but a portion had collapsed. He stopped at the broken place, holding his scraper down until he felt stone beneath the surface.
The gap was shallow near the wall and deep toward the current. He could wade across if the leather protected him long enough. After what the water had done to his boot, he did not trust it.
He explored the wall with his fingers. Old workmen had cut rough holds into the stone above the bank. Some were filled with slime. Lu Chen cleared the nearest, put the scraper away, and tested his weight on it. Stone crumbled under his thumb.
He moved to the next hold. This one stayed firm. He crossed with his chest pressed to the wall, placing each foot against the surviving edge. Halfway over, his left hand slipped. His body dropped, and he caught another recess with the injured wrist.
Pain made him gasp. His coat dragged through the water before he reached the far side. He knelt there, peeling the wet hem away from his legs. The cloth had stiffened and begun to smoke faintly. He scraped off the fouled mud rather than rub it into his skin.
Returning this way would be worse. He marked the safe holds with small pieces of broken slate, placing them where his fingers would find them. He had watched miners mark blind turns in smoky workings. Here the marks could save him from reaching for the rotten hold again.
The third grate stood in quieter water. Lu Chen loosened its hinges and found that the latch had already rusted almost through. He wrapped his scraper in cloth, struck the latch once, and waited through the long echo. Then he opened the frame without another blow.
Past it, his sight faded.
He sat on a dry ledge, shut off the flow to his eyes, and counted his breaths. The ring beneath his navel still turned, but the warmth it supplied was thinner. He could not replace that spent reserve here by gulping the poisoned air. Drawing from a stone would take time, expose the wrapping, and leave less for whatever happened outside.
He waited until his hands steadied, then continued with the smallest flow that would show the bank.
The fourth grate disappeared beneath hanging bodies.
A nest filled the upper corner. Cloudy threads tied the grubs together and ran down the frame. Under them, smaller pale forms crowded a hollow in the stone. Lu Chen stopped before his boot reached the first strand.
He backed away and crouched. The air was foul with wet shell and stagnant water. He remembered the first creature turning after his lamp. He had no lamp now, but to reach the upper hinge he would have to stand under the nest.
The lower footing remained clear.
He laid his coat on the bank to keep the flask from rolling, treated the lower pin, and waited. A grub shifted above him. Lu Chen pressed himself to the wall. His teeth began knocking together from the cold, so he held his jaw with one hand until they stopped.
When the softened pin yielded, he tested the frame. The upper hinge still held it. Pulling harder raised the metal toward the nest, stretching the cloudy strands.
He released it at once.
The frame settled with a low scrape. Two heads unfolded. Lu Chen stayed against the wall until they drew back into the crowded bodies. He could not force this without waking them.
There was an opening beneath the frame, packed with gravel and old wash residue. He cleared it with the scraper, working from the side rather than reaching under the nest. Dirty water ran through. The gap deepened enough for his shoulder, then his head. He shut the flask, tied it high against his chest, and lay down.
His face almost touched the runoff. He kept his mouth above it and pushed with his heels. The coat snagged. He could feel something crawling over the metal above his back.
He stopped pulling. With one hand he worked the caught fabric free, then slid forward again. On the far side he rolled onto his knees, dragging the scraper after him. His shirt was soaked at the chest. He opened it and checked the stone wrappings before moving on. They remained dry inside their double folds.
The fourth gate was not ready to swing open, but he had made a way under it. He left small stones along the clear side of the gap. He would need to recognize it without wasting sight on the whole nest.
The fifth and sixth grates took the remaining stretch of the watch. Lu Chen no longer examined every bar. He knew the fastenings now; where a pin sat too deep, he weakened the ear holding it instead. The work left his fingers raw. At the sixth, his scraper slipped from the joint and cut the heel of his hand. He bound it with another strip from his shirt and finished with the uninjured fingers.
The last barrier stood against a different darkness.
Air forced its way through the bars, bringing clean ice dust and the steady roar of wind over the outer glaciers. Lu Chen approached without touching the frame. He could see the pale slope below the outlet when clouds moved away from the distant sky. The world ended beyond the ice in the black reaches surrounding You Ming, but there was still mountain beneath this opening. He was not looking at a safe road.
He held the chart against the bars. Zhao had marked the outlet below the Third Watchtower, then a broken descent toward a southern hauling path. The line did not show every ledge. Lu Chen looked down until his eyes hurt, finding where the drainage lip met rock and where the rock vanished under ice.
If he opened the last grate now, the wind would pour through the whole siphon. The men in the occupied drift might hear it. He also lacked a sound rope, enough food, or any certainty about the descent. His hands could barely hold the chart.
He put it away.
The flask still held a little vitriol. He needed that for this final frame. He touched none of it to the iron. Instead, he cleared a patch of crust from the lower fastening so he could work quickly when he returned.
Then he began the long journey back.
He reset each loosened frame near its original sockets, wedging it with moss and soft wash residue. It would not survive a proper inspection. A casual glance from a tired worker might miss it. The fourth grate remained upright, its nest undisturbed above the narrow passage. Lu Chen crossed beneath it more slowly this time. His shoulder scraped the underside, and he had to swallow a shout.
At the broken bank he found his slate marks by touch. His wrist failed on the last hold. He landed on the dry side with both knees, scraping them through his trousers. For a while he could only sit there and breathe through his clenched teeth.
The first grate looked different from outside. The lamp tied to him bumped the frame, and he caught it before the metal rang. Beyond the low arch, his bucket waited where he had left it. He put a few dirty runoff jars from an abandoned rack inside. They were real forge vessels; bringing them back would support the story he had already told.
At the hoist, the winchman cursed the delay. He hauled Lu Chen up with a load of discarded props. The sentry inspected the bucket, saw the stained jars, and waved him through without touching the wrapped wrist.
Lu Chen reached the forge before the morning work began. He returned the lamp to its hook and laid the jars beside the wash trough. His limbs felt too heavy to arrange carefully beneath the blanket.
Across the hearth, Liu San was awake. He watched Lu Chen settle behind the flue, then looked toward the returned lamp. Lu Chen closed his eyes without explaining. His wrist continued to throb under the binding, and the final gate remained shut.