The Choked Vents

Why had the saboteur broken the scrubber drive shaft rather than cutting the primary glycol line? The air grew heavier against Kemo's teeth with every breath, tasting of sour copper and damp lime, while the radiator fins along the mess hall bulkhead still hummed with pressurized heat. If the handler intended to freeze them, they would have opened the bypass drain. By choking the vents instead, the attacker wanted twenty bodies gasping for breath on the floor, helpless to resist an orderly entry. Kemo adjusted the strap of his carbon pry bar against his ribs, his objective fixed: he had twelve minutes to climb the vertical intake riser, clear the fouled turbine housing, and pull the saboteur down before the carbon dioxide pool reached knee height.

"Seven minutes of clean air," Homi said, resting the butt of his iron bar on the galley counter. "After that, you'll be calculating your heartbeat in fractions. I give you five to one you come back dragging a frozen boot."

"Bar the latch behind me," Kemo said, gesturing toward where Tano and Sima sat pinned against the far bulkhead under Homi's watch. He stepped to the high access panel above the dry-storage rack, sliding the three-lug brass socket key into his palm. "If anyone touches the lower bleed valve before the blowers kick over, shoot through the mesh. No warnings."

Duli sat huddled against the cold metal of the pantry frame, her fingers wrapped tight in the sleeves of her oversized survival parka. Her mouth parted to cite some administrative regulation about life-support protocols, but Kemo had already seated the brass key into the triangular maintenance port. He torqued the head sixty degrees clockwise. The mechanical dogs disengaged with a sharp, heavy click.

He pulled the rectangular steel hatch open. A wall of dead, stagnant draft spilled into the mess hall, thick with pulverized coal-dust and the bitter tang of overheated bearing grease.

Kemo gripped the welded steel rungs inside the vertical riser and hauled himself upward.

The darkness closed in instantly, narrow and rigid. The duct was forty-six centimeters wide, boxed in galvanized sheet metal that vibrated under the distant shudder of the meteorological tower's wind turbines. Kemo kept his red utility torch switched off. Any stray beam would bounce off the zinc plating and announce his ascent to whoever waited at the upper bend.

He measured his pace by the contact of his rubberized boots against the iron rungs: one step every two seconds, shifting his center of gravity to keep his shoulders from scraping the galvanized seams. Ten rungs up, the air turned ten degrees colder. Frost coated the rivets like coarse table salt.

At the fourteenth rung, he paused.

A draft should have been pulling downward toward the habitat ring. Instead, the air hung dead. Three meters above him, past the elbow joint that fed into the primary intake manifold, metal tapped against metal. A deliberate, rhythmic scrape: an iron tool levering a stuck cam.

Kemo braced his left knee against a ladder rung and unclipped the carbon pry bar from his belt. He did not accelerate his breathing. The carbon dioxide accumulation in the vertical shaft was thinner than in the low ceiling pockets below, but the cold was biting through his heavy wool trousers.

He reached the ninety-degree junction where the vertical riser met the horizontal plenum.

The smell changed. Beneath the grease and coal-dust lay the distinct scent of winter petroleum: a heavy coating of animal lard and machine wax smeared over skin to insulate against subzero drafts.

The attacker was already in the crawlway, waiting inside the dead-zone behind the intake damper.

Kemo did not crawl straight into the horizontal duct. He slid the flat edge of his pry bar forward along the bottom lip of the galvanized plate, letting the tip drag with a light click.

The response came without a sound.

A steel wrecking bar struck the floor of the duct three inches to the left of Kemo's hand, punching a dent into the sheet metal that rang like a struck anvil. The blow had been aimed at where a man's collarbone would have been had he crawled in head-first.

Kemo hooked his right arm over the upper lip of the riser frame and drove his steel-toed boot straight upward into the dark void above the rim.

His heel connected with heavy canvas and dense muscle. A choked grunt echoed down the conduit. The attacker fell back against the damper frame, their boots sliding across the greased galvanized plate.

Kemo hauled his torso through the opening, dropping low to keep his back pressed to the steel floor. In the narrow clearance of the plenum, vertical leverage was impossible. The attacker lunged again, swinging the wrecking bar in a low, vicious arc designed to shatter ribs in the dark.

Kemo blocked the bar with the shaft of his carbon tool. The impact sent a numb jolt through his forearms, but the carbon composite held. Without resetting his grip, Kemo twisted his wrists, locking the attacker's steel bar between his tool and the corner rib of the duct. He drove his right elbow hard into the unseen face above him.

The strike hit cartilage. Warm blood sprayed across Kemo's knuckles, followed by the oily slip of the attacker's lard-smeared parka. The saboteur dropped the wrecking bar and lunged with two gloved hands, clawing for Kemo's throat to pin him against the frozen metal until the trapped gases finished the job.

Kemo did not fight the choke. He caught the attacker's left wrist with both hands, twisted his hips hard to the left, and used the narrow duct walls as a fulcrum to snap the joint outward against the steel corner.

The bone popped with a muffled crack.

The attacker shrieked, wrenching their body violently backward toward the upper exhaust damper that led out toward the meteorological tower. Kemo reached out and caught the nylon equipment harness slung across the saboteur's chest, hauling them back toward the riser lip.

The harness fabric tore under the strain. The attacker kicked out with a heavy crampon-shod boot, catching Kemo across the bicep. The blow tore wool and split skin, breaking Kemo's grip.

In the next second, the saboteur shoved through the flexible rubber winter seal at the far end of the plenum, tumbling into the high-velocity updraft of the tower exhaust. The hatch slammed shut behind them, locked from the outside with a drop-bar that clattered heavily into place.

Kemo did not chase. He stayed on one knee, drawing in slow, measured breaths of the biting air. His bicep throbbed where the iron point of the crampon had scored the flesh, but his fingers remained steady.

He clicked on the red penlight.

The narrow plenum floor was streaked with black machine grease, fresh droplets of dark blood, and the heavy iron wrecking bar the attacker had abandoned. Wedged between the secondary intake louver and the turbine rotor was the cause of the system failure: a solid steel turnbuckle jammed directly into the drive teeth, freezing the fan assembly in place.

Kemo wedged the tip of his carbon pry bar beneath the turnbuckle's forged eyelet. He leaned his full weight onto the lever. The frozen alloy groaned, fought the pressure for three seconds, and then snapped free with a sharp report.

The drive motor surged. The heavy steel blades of the intake turbine began to spin, slowly at first, then accelerating into a steady, rhythmic roar. A freezing rush of fresh, scrubbed air blasted down the vertical riser, cutting through the stagnant pockets of carbon dioxide like a clean blade.

Below in the mess hall, the faint sound of cheering floated up through the shaft, followed by two loud knocks on the rim.

Kemo bent down to gather the debris from the fight.

Beside the discarded wrecking bar lay the piece of nylon harness he had torn from the attacker's chest. Wrapped tightly around the shoulder strap was a two-foot length of heavy, shielded electrical wiring, cut clean with a ratchet shear.

Kemo brought the cable under the narrow cone of his red light.

The outer insulation was thick neoprene, but the core was unmistakable: five distinct strands of tinned copper wire, braided in an interlocking spiral wrap. This was not standard station maintenance stock. This specific five-strand braid belonged exclusively to the long-range high-frequency transceivers used by mainland syndicate vessels.

The person who had jammed the scrubbers had not scavenged their gear from the engineering shop. They were wired directly into the comms supply line.

Kemo coiled the braided wire into a tight circle, slipped it into his inner pocket beside Duli's keycard, and reached for the ladder to climb down.