Iven set the wrench on the bolt and struck its handle with a controlled piston push.
The bolt turned. The wrench also struck his thumb.
He bit back a curse, pulled the wrench free, and turned the bolt the rest of the way by hand. Pellan caught the loosened leg before it clattered to the floor.
“Through,” Iven said.
Elian had already crawled into the maintenance opening with the first leg. Sera followed, pushing the box of drill bits ahead of her. Pellan lifted the frame onto its side. Iven took the other end, and together they pushed it toward the opening.
The first creature came around the bend.
It was larger than the one beneath filter bank nine, its pale back almost level with Iven’s waist. Four thick limbs carried most of its weight; two smaller limbs folded against its underside and unfolded when it climbed over a low pipe. Its head was narrow, with the same dark pits along the side. A shallow groove crossed one plate, exposing a darker layer beneath.
The second creature followed close behind. A third shape moved in the dark beyond them.
Kesh held her hooked pole across the passage. She did not strike immediately. The first creature lowered its head and stopped, its front limbs spread on either side of a drain.
“Move the frame,” Kesh said.
Iven and Pellan shoved. The frame entered the opening, caught on the pipe inside, and stopped. Elian called from the other side that the lower leg was turned the wrong way.
“Can you lift it?” Pellan asked.
“Not from here.”
Iven handed him the frame and crawled into the opening far enough to reach the pipe. He could see the frame leg wedged beneath it. He reseated the winch pattern, using the few seconds Kesh’s position gave him, and drew the leg toward a metal ring in the wall. The frame shifted upward. Elian pulled from the far side, and it cleared the pipe.
“Go,” Iven told Pellan.
Pellan hesitated. “Kesh—”
“I’m still here,” Kesh said. “Go.”
The first creature advanced. Kesh struck the floor in front of it with the hooked pole. It paused, turned its head toward the impact, then rushed.
The pole caught beneath its front plate. Kesh pushed sideways, using the hook to redirect its head toward the wall. The creature struck the wall hard enough to shake dust from the braces. The second came around it, low and fast.
Iven rose from the opening and released the winch. He had the plate brace ready. The second creature came straight at him, and he placed the brace between its head and his legs. The impact drove him backward into the door frame. He caught the frame with his right hand and held the brace for one more breath while the creature scrabbled against it.
“Kesh, left,” he called.
Kesh hooked one of the creature’s smaller limbs and pulled it sideways. The limb folded. The creature lost its footing, struck the floor, and rolled against the first. Iven let the brace go before it drained him further.
Pellan crawled through the opening. “Iven!”
“Keep moving.”
Sera’s lamp appeared beyond him. She had turned back as far as the pipe. “The door on this side is clear. We can hold it once you’re through.”
The third creature emerged. Its plates were darker with moisture, and a strip of pale tissue hung from one joint. It did not rush them. It turned toward the bright replacement brace installed by the drilling crew and struck the base with a forelimb.
The metal rang. The creature struck it again.
Kesh saw it too. “The brace.”
“Later,” Iven said.
The first creature had recovered. It came at Kesh, who stepped back and caught its head with the pole. This time the hook slid across a plate instead of finding an edge. The creature knocked the pole aside and hit her leg. She fell against the wall.
Iven seized a length of rope from his belt and threw one end around the support ring above the passage. The loop caught. He pulled it tight, seated the winch, and drew himself toward the ring. His boots left the floor for an instant. He swung across the creature’s path and struck its side with the hammer in his right hand.
The blow did not break the armor. It turned the creature enough for Kesh to pull her leg free.
“Can you stand?” Iven asked.
“Yes.”
“Then get to the opening.”
Kesh took two steps and nearly fell. Her left leg was not carrying weight properly. Iven caught her under the arm and backed toward the maintenance opening. The second creature came after them.
Iven could not keep the winch, brace, and piston all ready while also holding the filter. He had already let the filter go. He had winch and brace seated. In the shelter of the wall, with Kesh leaning against him, he used his free hand to change the third channel from the unused path to the piston strike. It took long enough for the creature to close half the distance.
It lunged. Iven stepped aside, but Kesh could not move as quickly. Iven sent the piston force into the creature’s shoulder. The straight impact drove it into the support post. A plate cracked at the edge. The creature recoiled, then turned back toward them.
“Opening,” Iven said.
Sera reached through and caught Kesh’s arm. Pellan pulled from behind her. Iven pushed Kesh down into the opening, then turned to face the creatures again.
The first had climbed onto the wall brace, putting itself between him and the passage. The second shook its head near the support post. The third continued striking the bright metal at the base of the replacement brace. It tore a strip loose and dragged it across the floor.
Iven had no interest in killing all three. He needed enough time to get through the door. The frame and his companions were on the other side. The door was heavy, its hinge repaired with a borrowed bolt, and it would close if he could reach it.
He sprang toward the wall brace, using the spring-step pattern only after reseating it in place of the winch. The short change left him exposed. The second creature moved during the pause, and one limb caught his coat as he jumped. He cleared the low pipe but landed awkwardly, his shoulder twisting. The coat tore near the hem.
He struck the limb with his hammer. It released the cloth. He ran the remaining steps to the opening, dropped to his knees, and crawled in.
Something hit the wall behind him. The opening shook. He pushed himself over the pipe, scraping his forearm against its edge. The dressing on his graft caught, but did not come loose. Ahead, Sera and Pellan were pulling Kesh toward the repaired door. Elian held it open with both hands.
“Go,” Iven called. “I’ll close it.”
The first creature pushed its head into the opening. Its plates scraped against the sides. It was too broad to move quickly, but it kept coming, using the smaller limbs underneath to find purchase.
Iven reached the door and turned. The creature was halfway through. Closing the door on it might trap its head, but the door’s lower hinge was still only a temporary repair. If the animal forced it, the bolt might tear out.
Pellan shoved Kesh through the doorway. Sera followed. Elian stayed with his hands on the door.
“Let it go,” Iven said.
“We need you through.”
“I’ll be through.”
He seated the bell in place of the spring. The change took a few seconds. The creature’s front limbs reached the raised section beyond the pipe. Iven aimed at the floor just ahead of it and released a short pulse.
The vibration struck the metal walkway. The creature recoiled, its head pulling back into the opening. It did not flee. It lifted one limb, testing the surface that had struck it.
That was enough.
Iven stepped through. He and Elian pulled the door shut together. The creature hit it once from the far side. The temporary hinge held. Pellan dropped a heavy bar across the door brackets, and Sera moved Kesh farther down the passage.
They waited. A second impact came, then a scrape. The door shuddered but stayed closed.
Kesh sat against the wall and pressed her hand to her leg. “I think the knee is intact.”
Sera examined it. “You don’t get to decide that because you want to walk.”
“I was going to decide it because I don’t want to be carried.”
“That’s a different problem.”
She found a deep bruise and a swelling along the outside of the joint. Kesh could move her foot and bend the knee a little. Sera bound it with a strip of cloth and told her to test her weight slowly. She stood with Pellan’s help, grimaced, and stayed upright.
The noise behind the door faded. Iven checked the bar, then the hinge bolt. It had bent but not pulled free.
Elian looked at him. “You could have closed it while the creature was still in the opening.”
“Yes.”
“Why didn’t you?”
“The hinge was weak. If it broke, we’d have a creature and a door in the same passage.”
“That wasn’t what I meant.”
Iven wiped dust from his hammer. “It was trying to get through. So was I.”
Elian studied the door. He did not ask whether Iven had spared the creature out of kindness. Iven was grateful. He had been frightened and had made the choice that seemed most likely to keep the door standing. If kindness had benefited from it, that was welcome.
Kesh leaned on her pole and took a careful step. “The third one went for the brace before it came for us.”
Pellan frowned. “The first two came straight at us.”
“They did. I want to know why the third didn’t.”
“It might have been behind them.”
“It might.” Kesh looked back at the door. “We need more than one observation.”
They carried the drill frame along the raised passage. Kesh insisted on walking until Sera threatened to leave her in a chair at the next landing. Pellan took the heavier end of the frame. Iven carried the detached leg and the box of bits, giving Elian a free hand for the map.
At the removed ladder shaft, the upper passage connected to a sloping service ramp. The ramp was longer than the old route, but it avoided the flooded section and the bad air near the vent. Elian marked it clearly, including the narrow opening and the temporary hinge repair.
“Will someone replace the bolt?” he asked.
“I’ll put it on the work slip,” Iven said.
“Will that make them do it?”
“No. It will make it harder for them to say they didn’t know.”
The last part of the journey took longer than the first because Kesh’s leg stiffened. They stopped twice so Sera could check the swelling. At the surface lift, Tavin was waiting with Cage Seven. He took one look at the group and opened the gate without asking a question.
When they reached the landing, he helped Kesh onto a bench. “Bad day?”
“Useful day,” Kesh said.
“That sounds worse.”
Iven set down the drill frame. His thumb had begun to ache where the wrench had struck it, and his torn coat hung unevenly at the hem. His graft felt warm and low on charge, but the patterns were still there when he checked them: bell, winch, filter, plate, piston, spring. Nothing had vanished because he had used it.
Sera crouched beside Kesh. “You’ll need to rest that knee.”
“I have notes to make.”
“You can make them sitting down.”
Kesh looked at Iven. “I owe you.”
“You told us when to leave the door closed.”
“And you got us through the other one.”
“Then perhaps we’re even.”
Kesh gave him a measured look. “I don’t think so. But I can wait until you decide what to ask.”
Behind them, the lift gate closed. Below, the pale creatures remained on the far side of a repaired door, in a passage where someone had drilled into a moving wall. Iven had won the fight that mattered: everyone who had gone below had come back. He had also brought back a question that was unlikely to stay behind that door.