Scaling the Vertical Shafts

How long does it take an imperial suppression quarrel to drop seventy vertical feet through a wet chimney?

Alvaro Salgado pressed his shoulder blades flat against the freezing basalt flue, his boot heels wedged into a two-inch mortar groove, and counted the fractions of a second. Above them, the brass horn of an imperial command harness barked another harsh directive, followed by the heavy, ratcheting click of four siege arbalests drawing tempered steel bowstrings back to their notches.

"Move, suit!" Inesita hissed from three paces above him. Her fingers, stained with dark copper-green Raíz soot, dug into a crumbling masonry ledge. Her ironwood trench pick was slung across her shoulders, its pick-head ticking against the bronze buckles of her salvage harness with every shift of weight. "They aren't firing warning shots."

A heavy iron bolt struck the masonry six inches to Alvaro’s left. The impact sprayed razor-sharp stone splinters across the wet collar of his leather coat, accompanied by the biting reek of distilled vitriol and pulverized lime. A second quarrel struck five feet lower, punching clean through a corroded drainage conduit and venting a jet of scalding sulfuric steam into the draft.

Alvaro did not look down. He flattened his left palm against the slick stone. Condensation ran in cold, steady rivulets down the granite, soaking through his split leather gloves.

The icy moisture seeped through his skin, converting the ambient hydraulic pressure into a thin pulse of vigor that steadied his shaking calves. It was slow, far too slow to offset a seven-story climb under direct fire, but it gave his burning muscles enough purchase to hold the vertical rock face.

"Four gunners, firing in sequence," Alvaro called up, keeping his voice low beneath the roaring draft of the chimney. "The crank cycle is four point two seconds. When the fourth bolt strikes, we have a one-point-six-second blind spot while the line resets their pawls."

Inesita kicked her boot into an iron conduit bracket, hauling herself upward with fluid, unnatural grace. The green-tinged veins along her forearms flared with dull jade luminescence, absorbing the physical inertia of the climb and converting it into pure upward momentum.

"I don't need an audit of their loading drills, clerk," she muttered, grabbing an intake rundle twenty feet above the lower junction. "I need you not to catch a half-pound of forged steel through your spine."

"An audit is the only reason you know when to duck," Alvaro countered.

He waited for the cadence. The acoustics of the chimney acted as a natural amplifier, carrying every mechanical tell of the imperial squad stationed at the upper customs baffle.

Clack-whir. The heavy iron spanning levers completed their second revolution.

Thump. The third arbalest released its catch.

The quarrel ripped through the air, shearing a flap of leather from Alvaro's left sleeve before embedding itself four inches into the granite ledge where his shoulder had rested a half-heartbeat prior.

"Now," Alvaro said.

He shoved off with both heels, driving his weight upward. He caught a rusted rung of an old maintenance ladder with his left hand, while his right hand kept a white-knuckled grip on his brass measuring cane. The metal was cold, scored by the lightning of the desynchronization pulse he had channeled in the chamber below, but the internal balance of the rod remained true.

Above them, fifty feet up the shaft, an orange flare ignited behind a heavy iron grating. The light cast harsh, cage-like shadows down the wet rock walls. Alvaro smelled the distinct, sickening sweetness of pitch and pulverized charcoal—the standard incendiary mix used by Imperial Purification units to sterilize compromised vaults.

"They're preparing the purge burn," Alvaro called out.

"I can smell it from here," Inesita snapped. She leaped from the conduit bracket, her trench pick flashing out to bite into the mortar joint directly beneath the mid-shaft baffle cradle. "The baffle's moving! They're dropping the quarantine slab!"

A deep, groaning shudder vibrated through the chimney. High above, two massive cast-iron fire-baffles—each four inches thick and studded with cold-rolled reinforcement ribs—began to slide down their vertical guide rails. The counterweight chains clattered over grooved bronze pulleys with a deafening, rhythmic clatter.

If those slabs dropped into their locking shoes, the chimney would be sealed permanently, and the Cohort would vent three hundred gallons of pressurized liquid pitch down the flue to incinerate everything inside Sub-Vault 4.

"Distance to the baffle lip?" Alvaro demanded, pulling himself onto a narrow brick ledge forty feet above the floor.

"Twenty-two feet," Inesita called down, her boots scraping frantically for purchase on the slimy stone. "And the drop rate is faster than our climb. That iron will seat before we reach the half-mark."

Alvaro focused his vision on the descending iron plates. The red lines of his Discrepancy Ledger traced the mechanical assembly: two heavy bronze guide blocks, an overhead pneumatic regulator valve, and a pair of cylindrical lead-shot counterweights suspended from eight-gauge iron chains.

The Códice-engineered regulator was designed for the dry, uniform pressure of standard imperial facilities. Here, inside the humid, anomaly-warped chimney of Sub-Vault 4, the compressed air inside the piston was suffering from thermal variance. Every stroke of the regulator lagged by just over a third of a second.

"Inesita!" Alvaro called out. "Your salvage rope! Hook the counterweight chain!"

"The baffle is falling, idiot! The weights will crush us!"

"The slab is dropping, which means the counterweight is being yanked up!" Alvaro yelled back. "Anchor the line to the counterweight side! The falling slab pulls our mass straight up the shaft!"

Inesita did not waste time arguing. She unclipped her heavy braided salvage cord, whipped the iron grapnel twice in a tight overhead circle, and cast it upward through the narrowing chimney.

The three-pronged iron hook struck the ascending links of the counterweight chain with a sharp metallic clink, slid two feet, and locked securely into a master link.

"Anchored!" she shouted.

"Take the wrap!"

Inesita knotted the secondary lead around her harness carabiner and kicked hard off the chimney wall. As the heavy iron baffle plunged on the far side of the pulley, the rising counterweight chain snapped taut, yanking Inesita straight up the shaft in a sudden, violent arc.

She flew upward through the spray of water and vitriol, clearing fifteen feet of wet stone in less than two seconds.

Two arbalest bolts cracked downward from the customs grate, one grazing her utility pouch and slicing a clean tear through her spare canvas pack, but she was moving too fast for their sights. She caught an exhaust strut just four feet beneath the closing baffle plate and braced her boots against the frame.

"Your turn, suit!" she screamed down through the smoke. "Line's trailing!"

Alvaro gripped his brass cane with his teeth, caught the dangling tail of the salvage rope with both hands, and braced his heels against the wall.

He didn't wait for his stamina to regenerate further. He wrapped the rough hemp cord twice around his right forearm and threw his entire body weight backward into the void.

The upward jerk nearly dislocated his shoulder. The rising chain hoisted him off the ledge with brutal force, the air rushing past his ears filled with the roar of falling water, the hiss of descending iron, and the sharp crackle of arbalest fire.

A stray quarrel ricocheted off the brass shaft of his cane, jarring his jaw and filling his mouth with the metallic taste of blood. Another bolt thudded into the brickwork an inch beneath his trailing boot heel.

Thirty feet. Forty feet. Fifty feet.

He was ten feet below the baffle when the mechanism began its final seating stroke. The two massive iron slabs were only three feet apart, converging like the jaws of a crushing vice.

"The gap's closing!" Inesita warned, her hands straining against the exhaust frame. "The regulator kicked into emergency bypass! It’s dropping dry!"

The pneumatic regulator had bypassed its latency buffer. Judging by the sudden pressure drop, the Cohort commander above had pulled the manual tripwire, severing the air cushion to let the three-ton slabs free-fall into their stone grooves.

If Alvaro hit the slabs at this speed, the iron would cleave him in two before he cleared the aperture.

Alvaro spat the blood from his lips, shifted his grip on the cane, and locked his gaze onto the overhead pneumatic valve housing.

"Hold your brace!" Alvaro shouted.

He channeled the cold, oily pressure running along his left arm. The Raíz-corrupted veins beneath his skin pulsed with dark emerald static, drawing the residual kinetic charge from his climb and directing it straight into the brass core of his measuring cane.

He drove the cane's tip upward, striking the bronze synchronization housing just as the descending slab entered its final eighteen inches of travel.

A sharp, high-pitched ringing cracked through the chimney.

A visible ring of distorted, gray-and-green static erupted from the point of impact. The pulse shot straight up the bronze fluid lines, overloading the mechanical logic bus inside the regulator. The internal release valve snapped closed on an unscheduled pressure spike.

The massive iron baffle slammed to a screeching halt, suspended six inches above its bottom seal by a shuddering cushion of trapped hydraulic air.

"Through! Now!" Alvaro roared.

Inesita hooked her fingers under Alvaro's coat collar and hauled him with fierce, tendon-straining power through the narrow eighteen-inch gap between the frozen slab and the stone lintel.

As Alvaro slid across the metal housing, his Cold-Iron Extraction Shears clamped down on the exposed master bypass valve, shearing off the polished brass locking key in a single, practiced twist.

Alvaro tumbled through the opening, his boots clearing the threshold just as the two-second fault window expired.

BANG.

Behind them, the three-ton iron slabs broke through the jammed valve and slammed into the granite floor with a shockwave that rattled the teeth in Alvaro's skull. The sound of pressurized pitch immediately hissed against the sealed lower surface, filling the small maintenance crawlspace with boiling heat and the muffled roar of flames.

Alvaro lay flat on the cold, polished flagstones of the upper exhaust duct, his chest heaving, his stamina pool flashing amber in the corner of his sight.

Beside him, Inesita collapsed onto her back against an iron ventilation louvre, her breath rattling in her throat. She wiped a smear of black grease from her cheek with the back of her sleeve and looked down at the dented brass measuring cane Alvaro still clutched in his hand.

"You make dodging twenty-pound iron counterweights look like filing a late tax assessment," she muttered between ragged gasps.

"A late tax assessment carries steeper interest penalties," Alvaro replied, his voice dry and hoarse from the soot. "The late fees alone would have killed us."

Inesita gave a short, breathless snort. "Remind me never to look at your family's ledger books."

Alvaro sat up slowly, testing the joints in his shoulders. His coat was ruined, the left sleeve hanging in scorched ribbons, and his ribs ached from the violent jerk of the counterweight chain. But his fingers were steady.

Before them lay the heavy bronze intake grate that separated the exhaust crawlspace from the main transit floor of the San Marcial Imperial Customs Terminal. Through the diamond-shaped perforations in the bronze metalwork, Alvaro could see the vast, vaulted expanse of the surface facility: rows of polished white-granite processing counters, suspended brass lanterns burning clean, odorless alchemical oil, and the immense pneumatic message tubes that crisscrossed the vaulted limestone ceiling.

After the claustrophobic rot and toxic flumes of Sub-Vault 4, the clean, conditioned air of the upper terminal felt unnaturally sterile.

"We have an issue," Inesita whispered, her tone instantly losing its light edge as she peered through the grating.

Alvaro leaned forward and looked through the bronze slats.

Standing in a semi-circle fifteen paces from the exhaust duct was an entire squad of Imperial Customs Bailiffs, accompanied by four heavy-infantry troopers from Purge Cohort Detachment Three.

Their polished brass cuirasses were unmarked by soot, gleaming under the bright lantern light. The bailiffs held long-hafted bills and iron manacles, while the four Cohort soldiers leveled heavy, double-strung arbalests directly at the exhaust housing.

At the center of the formation stood a tall, thin customs magistrate wearing a crisp, indigo-dyed wool tunic lined with silver ermine. A heavy leather manifest book rested on a portable lectern before him, and his right hand hovered over a glowing Códice authorization stamp.

"Sub-Vault 4 maintenance exhaust," the magistrate announced, his voice flat, emotionless, and amplified by the terminal’s acoustics. "By imperial decree and the authority of the High Customs Tribunal, this facility is under total biological and administrative quarantine."

The four arbalest cocking levers clicked in unison, drawing their bolts to full draw.

"Step out of the grate with your hands empty and your interface unlinked," the magistrate continued, turning a crisp parchment page in his ledger. "Any unverified movement, unregistered artifact, or unauthorized signature will be met with immediate lethal liquidation."

Inesita slowly reached down toward the ironwood trench pick at her side.

Alvaro reached out, his soot-blackened hand clamping firmly over her wrist.

"Don't," Alvaro said softly.

"They aren't taking my salvage, suit," she hissed under her breath.

"They won't," Alvaro whispered back, his fingers tracing the cold, sharp edges of the Códice Master Matrix secured inside his inner pocket, and the freshly severed imperial pneumatic trigger key he had stripped from the baffle housing during their escape.

He stood up, dusted the soot from his torn lapels, and laid his brass measuring cane flat across his forearms in the formal posture of an Arbiter’s apprentice.

"Let me file the paperwork."