Ascent Through Soot

How many pounds of frozen gristle did it take to snap a three-inch drive shaft?

Chief Engineer Berglind did not intend to let the factory answer that question with her bones. Clinging to the vibrating iron rungs of the vertical service ladder, she climbed out of the suffocating heat of the Deck Four switchboard and entered the open updraft of the central shaft. Below her boots, the air was thick with the stench of scorched tallow and ozone. Above, the catwalks clung like rusted iron ribs to the brick chimney of the Citadel, lost in swirling plumes of coal soot and condensing water vapor.

Her right shoulder burned where the strap of her leather webbing bit through her tunic. Slung at her hip, the six-pound iron spanner she had taken from her dead apprentice clanked rhythmically against her steel pinch-bar with every rung she gained.

Thirty paces below, through the hexagonal perforations of the exhaust decking, a sudden flare of blue electrical discharge lit the fog.

Berglind paused on a narrow resting collar, wiping black grease from her brow with the back of her wrist. Through the iron grating, she caught the silhouette of Kolskegg’s broad leather butcher coat moving through the grease flue approach, flanked by two figures carrying heavy cleavers and a Watchman whose stun-baton sputtered in dying bursts. The butchers were cutting their way toward the boiler flues. Kolskegg was driving them hard, leaving a trail of hacked marrow and shattered iron shackles behind them.

"Still breaking my floorplates," she muttered under her breath.

According to Section Nine of the Citadel Boiler Code, getting chewed to pieces by uninspected livestock while trespassing on an overhead service track constituted an unauthorized shift extension punishable by a docket dock. If Kolskegg survived the night, she promised herself, she would personally hand him the repair bill for every bent girder on Deck Three.

She hauled herself onto the primary gantry catwalk.

The gantry was a six-foot-wide suspended bridge of bolted iron mesh, trembling under the violent oscillation of the main drive axle. To her left, the overhead carcass conveyor chain ground along its steel guide rails, moving at twice its rated operating speed. But the hooks no longer carried quartered cattle or dressed hogs.

They carried twitching mounds of fused gray flank, bristling with half-formed ribs and blind, blinking eye clusters. The meat hung down into the clearance space, slick with yellow bile that dripped onto the handrails.

Berglind unhooked the pinch-bar from her harness. The emergency gear train was eighty yards ahead, mounted on a reinforced staging platform directly above the Deck Four pressure split. If she could reach the manual drop-weight lever, she could drop the secondary safety clappers, venting the freezing pipes before the hydraulic shock wave shattered the whole manifold.

A wet hiss scraped across the roar of the reduction gears.

From a passing overhead trolley, three separate clusters of meat dropped onto the iron mesh twelve paces ahead of her. They did not roll. They hit the deck and flattened, sprouting segmented, calcified bone-spurs that drove into the mesh for traction. The center mass was the size of a hog's thorax, pulsing with wet, fibrous cords that anchored directly into the links of the conveyor chain above it.

It lunged forward with a sharp, hydraulic snap.

Berglind did not back down the narrow ladder. The drop was eighty feet into the grease vats, and the ladder offered no leverage for iron. She stepped into the center of the gantry, plant-foot locked over a cross-girder, and brought the heavy pinch-bar down in a two-handed arc.

The chisel-tipped steel bit deep into the leading bone-spur, shearing the calcified marrow in a spray of curdled blood. The creature shuddered, its wet ribs contracting to clamp around the bar. Berglind did not struggle to pull it free. She twisted the tool forty-five degrees, levering the creature sideways into the exposed teeth of the six-foot reduction flywheel spinning beside the walkway.

The bronze gear teeth caught the fibrous meat. With a wet, muffled crunch, the flywheel dragged the mass into the meshing train, pulverizing muscle and bone against the cast-iron housing. Dark grease and black tallow splattered across Berglind’s leather apron and goggles.

The other two masses dropped from the rail behind her, cutting off the ladder.

One of them whipped a rope-like tendon toward her knee. Berglind felt the cold, wet sinew wrap tight around her boot calf, jerking her backward toward the edge of the unrailed catwalk. Her balance tipped. The open air of the shaft yawned below her right elbow.

She drew the dead apprentice’s six-pound spanner from her belt. Instead of hacking at the tendon, she swung the heavy square head of the tool straight down onto the anchoring nodule where the creature clung to the iron floorplates. The blow shattered the creature’s central cartilage ring with the sound of breaking pottery. The tension in the tendon snapped slack.

Before the third polyp could spring, Berglind jammed the flat end of her pinch-bar into the secondary gear lock beside the rail. The hardened steel wedge jammed the teeth of the secondary drive spindle. The machinery shrieked, sparks showering the damp catwalk as the sudden mechanical seizure wrenched the overhead rail trolley sideways, ripping the third creature from its perch and flinging it out into the empty air of the ventilation shaft.

Silence returned to the gantry, broken only by the hiss of failing steam.

Berglind drew three ragged breaths through her teeth, her forearms aching from the impact. She wiped her goggles on her shoulder and retrieved her pinch-bar from the stalled spindle.

She ran the remaining thirty yards to the emergency staging platform.

The platform hung suspended by four heavy tension rods above the central steam junction. Near the wall, a foreman’s iron muster locker stood half-open, its padlock sheared by a cold-chisel. Inside lay the slumped, bloodless body of Shift Foreman Ormur, his chest cavity hollowed out by sharp extraction tools rather than claws.

Berglind did not linger on the dead man's face. Her eye caught the brass dispatch canister clamped under his dead arm. She ripped it free with a sharp yank, snapping the tin inspection wire.

Inside the tube was an uncorrupted vellum schematic: the secondary high-pressure grease bypass routes leading directly beneath the central boiler house. It was stamped with Ormur’s personal shift seal, detailing an unmapped maintenance siphon that bypassed the contaminated central elevator shafts entirely.

A sharp, metallic ping echoed through the iron framework.

Berglind turned toward the manifold. The three-foot copper relief lines running from the lower decks had stopped venting sulfur vapor. Where scalding steam had hissed moments ago, a creeping crust of white frost was spreading across the brass fittings.

The cold arrived not with a drift of winter air, but with the sudden, violent shock of a collapsed vacuum. Condensation froze solid on the handrails in seconds.

The biomass had not simply blocked the steam. It had extinguished the thermal core below.

Under Berglind's boots, the entire four-ton staging platform gave a heavy, sickening shudder as sixty feet of overhead cast-iron piping fractured under the ice shock.