The interior of the vertical conduit was a vertical choke point of whistling steam and black iron rungs.
Daxian climbed with his left hand, his fingers slipping twice on the greasy coating of the ladder before his boots found a stable ledge. The heat inside the shaft rose exponentially with every yard, pressing against his ribs like a heavy, iron plate. Beneath the stained silk wrapping his right forearm, the raw skin began to prickle, a wet, boiling sensation indicating that the solvent was already eating through the outer layers of the sludge crust.
Ten feet below him, Vesper's respirator hissed erratically, her boots kicking loose flakes of rust that drifted down into the dark abyss like falling soot.
"The pressure gauge on the bypass wall is stuck in the red zone," her muffled voice echoed through the iron tube. "The secondary relief valve isn't cycling. The line is completely backed up from the primary reservoir."
Daxian reached the small, semi-circular maintenance platform where the manual bypass wheel sat. The iron loop was caked in a thick, crystalline lime deposit, its surface hot enough to make the air directly above it shimmer. He braced his feet against the grating and reached out with his left hand, slamming his palm against the rim to break the seal.
The wheel didn't budge.
He repositioned his stance, digging his boots into the rusted mesh of the platform. He grabbed the top rim with his functional left hand and shoved with his entire body weight, his teeth grinding as his cracked ribs shifted under the strain. The iron groaned, but the calcified threads held fast, locked tight by decades of automated neglect.
"Use the rod," Vesper grunted, her head clearing the edge of the platform as she pulled herself up. She was trembling, her left leg dragging slightly as she wedged herself into the narrow space behind him. "Shove the point through the spokes. We need the leverage."
Daxian took the iron sorting rod from her strap, sliding the tapered tip between the crusty spokes of the wheel until it locked against the central housing. Together, they leaned their weight onto the iron bar.
The calcified lime cracked with a sound like a pistol shot. The wheel rotated three inches, but instead of the clean whistle of an open vent, a high-pitched, deafening squeal tore through the pipe seams. A sudden spray of boiling, dark gray solvent hissed out of a split gasket directly above the wheel, striking Daxian's wrapped forearm dead-on.
The makeshift sludge seal didn't hold.
The high-temperature liquid instantly dissolved the outer layer of gray crust, turning the mineral paste into a runny, boiling fluid that scalded the high-tier white silk underneath. Daxian stumbled back, his spine slamming into the curved wall of the shaft as a white-hot spike of pain shot up his arm. The silk began to smoke, the synthetic heat tearing into the fragile iron-wood graft beneath his flesh.
"Get back!" Vesper lunged forward, her gloved hand catching the lever of the rod to pull it out of the spray, but the pressurized steam caught the edge of her leather sleeve, turning the material brittle and black within seconds.
She dropped the rod, her boots slipping on the wet grating as she fell against his chest. They were trapped in a four-foot iron circle, the boiling mist expanding rapidly, cutting their visibility down to zero while the automated extraction pulse from the quarry below thudded through the iron walls like a dying heart.
Daxian pressed his injured arm against his chest, his breathing coming in ragged, short gasps. The calculated solution had completely failed. The silk weave was too porous, and the mineral sludge lacked the base density to withstand the direct spray of an un-filtered line.
"The line... is going to purge," Vesper choked out, her fingers clawing at the filters of her respirator mask as the acidic steam began to bypass her seal. "If the main valve doesn't drop now, the total column of solvent will drop right through this shaft."
Daxian forced his eyes open, his vision swimming with gray spots as he stared through the hissing plume of steam.
He didn't look at the wheel. He looked at the split gasket where the fluid was escaping.
The spray wasn't coming from a broken pipe; it was venting from a small, square diagnostic port that had been manually bolted over the original framework. The bolts weren't standard Father-issue logic pins. They were crude, hexagonal iron plugs—the exact same scrap-iron style Bram used to reinforce the jaw components in the drift camp.
The collector hadn't just modified the spire below; he had physically altered the internal plumbing of this maintenance shaft to divert a portion of the un-filtered ink into a hidden secondary reservoir.
"The block... isn't electronic," Daxian said, his voice straining against the heat.
"What?"
"The bypass wheel is a dummy," he muttered, his left hand reaching down to grab the discarded sorting rod from the grating. "The collector locked the true line behind the diagnostic plate. He wanted the automated system to think the valve was closed so the garrison wouldn't track the flow."
He didn't try to turn the wheel again. He drove the flat, chiseled end of the sorting rod directly into the gap beneath the square diagnostic plate, using the split gasket as a fulcrum point.
"Help me slam it," he told her.
Vesper didn't ask for a philosophical explanation. She threw her shoulder against his left side, her small frame adding just enough weight to shift the rod. Daxian shoved the iron bar home with a desperate, singular heave, his right arm dangling uselessly as he poured his remaining physical strength into the pry point.
The square iron plate tore free from its hexagonal plugs.
A deep, hollow thud resonated through the length of the vertical shaft as the true internal gate dropped open. The whistling steam stopped instantly, sucked down into the lower reservoirs by the sudden release of vacuum pressure. The boiling spray vanished, leaving only the wet, dripping silence of the dark pipe and the heavy, copper-scented air between them.
Daxian slumped against the rungs, his left hand barely holding the rod as he looked down at his ruined forearm. The silk was charred black, stuck to the raw, blistered surface of his iron-wood graft, but the core inside his chest remained stable, its purple fractures silent.
Vesper rested her forehead against the cool iron of the ladder, her respirator emitting a long, mechanical sigh as the internal filters cleared. She looked at the open diagnostic port, then at the broken hexagonal bolts scattered across the platform.
"He's running a parallel line," she whispered, her gray eyes dark with a new, deeper paranoia. "The collector isn't just stealing material for a monument. He's building an entirely separate network infrastructure right through the bone of this layer."
"And the Filter above us is what keeps the two systems from touching," Daxian said, his voice flat as he pulled the charred remnants of the silk from his skin. "We aren't just climbing a shaft, Vesper. We're walking inside a thief's pocket."
He didn't offer to patch his arm again. He took the sorting rod, hooked it over his shoulder, and reached for the next rung above the open port. The obstacle was bypassed, but the reality of the forge above had just become twice as complicated as the maps had promised.
"Let's move," he said, his boots finding the iron path once more. "Before the thief notices the leak has stopped."