Venting the False Surge

The cold in the unpressurized service trunk bit straight through Levmir’s canvas sleeves, but he kept both hands clamped around the brass flask. He had nine minutes left before Overseer Kordov’s pneumatic drill tore into the bulkhead of Vault 4B, and three decks of frozen zero-gravity piping separated him from the dead radiator manifold in Sector 9. If the drill punch shattered the glycol lines first, Mash Vat Seven would boil off into the porous asteroid rock before he could vent a single drop of slurry.

"Move your boots, Brewer," Olenka whispered through her suit radio. She floated two meters ahead in the cramped gloom, hauling herself along the conduit ribs with rhythmic pulls of her gloved wrists. "The high-pressure line on Spine Three just charged. I can hear the hammer strokes through the structural steel."

Levmir felt the vibration through his palms as he gripped the guide rungs. It arrived as a dull, mechanical thrum: three beats per second, heavy and relentless. Kordov was anchoring the forty-millimeter kinetic drill rig to the deck plates outside the brewery door.

"How far to the bypass tee?" Levmir asked, keeping his breath steady to avoid fogging his inner faceplate.

"Forty meters. Hatch nine-echo." She kicked off an anchor flange, drifting smoothly through the dark bore of the pipe without brushing the ceiling. "Watch the frost on the left guide rail. That line leaked fluorocarbon sixty years ago and never got scraped. Touch it with bare skin or a torn gauntlet and you'll leave your knuckles behind."

Levmir tucked his knees and pulled along the upper conduit. Zero gravity turned every errant kick into wasted momentum and tumbling drift, so he worked strictly with his forearms, keeping the fifty-kilowatt yeast culture braced against his ribs. The brass sleeve radiated a steady, feverish warmth through his insulated vest, smelling faintly of toasted malt, wet slate, and scorched copper.

"You smell like a bakery on fire," Olenka muttered over the link, checking the clearance behind her.

"It is thirty-six percent fermentable sucrose," Levmir said, checking the mechanical pressure dial recessed in the flask's neck. "The heat is the point."

"Tell that to the enforcers when they sweep the shaft for your crumbs."

She caught a structural brace with her boot hook and swung down into a narrow cross-junction. A circular hatch of pitted boiler plate blocked the forward passage, sealed by a heavy bronze hex-fitting encrusted with dried pipe grease and graphite paste. Above it, the stenciled designation read RAD-SEC-09 / RET-LOOP.

"This is it," Olenka said, clearing away a brittle web of frozen mineral scale with her gloved thumb. "Secondary loop for the old smelter fins. It’s been dry and depressurized since the third cooperative strike."

Levmir pulled Ignat’s antique six-lug key from his harness. The bronze had darkened with age and oil, but its machined teeth matched the recessed slots in the valve housing with exact tolerances. He slotted the key into the collar and braced his boots against the opposing structural rib of the shaft.

The metal resisted with a sharp, dry shriek. Decades of hard vacuum friction and atomic contact had cold-welded the exposed threads together. Levmir unclipped his twelve-inch spanner, locked the hardened jaw across the key's square drive shank, and threw his entire upper body against the lever.

The valve gave way with a crack that resonated through the metal framework like a hammer blow. A tiny puff of ancient, desiccant gas hissed into the conduit and vanished instantly into the dark vacuum.

Olenka reached past him and pulled the threaded inspection cap clear. "The jacket is empty. If you dump that mash in there, won't it just freeze solid before it hits the exterior fin?"

"Pure mash would freeze in seconds," Levmir said. He unscrewed the delivery nozzle from the brass flask and threaded its tapered collar directly into the purge port. "Strain 9-Delta does not freeze while it consumes sulfur tailings. It expands at three bar and dumps fifty kilowatts into the aluminum cladding."

He opened the flask's knurled needle valve two full turns.

Inside the borosilicate core, the dense brown slurry surged under internal pressure through the copper delivery tube. Levmir monitored the pipe's exterior surface temperature using the magnetic contact thermocouple on his wrist display. The baseline of the dead metal read minus forty degrees Celsius.

Within five seconds, the digital dial jumped. Minus twenty. Zero. Plus forty.

The yeast hit the residual mineral dust clinging to the walls of the dry ammonia jacket. Starved for heat-sinks in the vacuum of space, the engineered cells tore through the sucrose and iron sulfide, throwing their metabolic waste outward as pure, radiant infrared energy. The dead radiator fin, stretching fifty meters out into the vacuum along Sector 9’s forgotten exterior spine, began to glow intensely hot against the station’s automated thermal telemetry.

"Look at the regional repeater," Olenka whispered.

She held up the maintenance slate strapped to her forearm. Across the cooperative's central diagnostic network, an amber diagnostic block flashed, shifted to vivid crimson, and began blaring an automated runaway warning. The central grid registered an unlogged forty-eight-kilowatt thermal bloom rising at six degrees per second in Sector 9's peripheral bedrock.

A secondary alarm followed immediately across all channels: COOLANT RUPTURE DETECTED. CORE RUNAWAY SUSPECTED.

A burst of static ripped across the wide-band security channel, followed by shouts from the dispatch bunker. Overseer Kordov’s harsh voice cut through the drone of the alert sirens.

"All squads on Spine Three, belay the breach drill," Kordov commanded, his voice tight and clipped. "Unclamp the pneumatic rig immediately. We have an uncontained reactor flare in Sector 9. Full tactical redeployment. Double-time."

Through the conduit steel, the heavy thrumming of the breach drill abruptly ceased. Seconds later, a succession of rapid clangs traveled through the deck girders as heavy magnetic boots disengaged from the floor and sprinted toward the transit cars on the outer ring.

Levmir uncoupled the empty flask, sealed the purge port with a threaded brass plug, and torqued the hex collar tight with his wrench.

"They took the bait," Olenka said. She stared at the flashing red telemetry on her slate, then looked up at Levmir through her scratched faceplate. "Kordov pulled every man off Sub-deck 9. Sector 4 is clear."

The corridor outside Vault 4B was silent again. The Spirka vats were untouched, and the primary access route to the lower core lay completely unguarded.

Levmir wiped a smear of condensation from the needle valve and stowed his wrench back into his canvas harness. "Let them chase the heat. We have six hours before that fin cools down."