The Cold Run

How much did a pipe-walker value her life when the alternatives were freezing in the dark or taking a bribe from a condemned brewer? Levmir looked down at Olenka's hand on his sleeve, the green crust of dissolved Monel-400 flaking between her fingers in the dim amber of Vent Junction 12. He had barely an hour before Kordov's patrol cycled back through the upper plenum, and every second spent in this crawlway cost him pressure.

"I was keeping your ration lines from turning to slush," Levmir said. He did not pull his arm away. Abrupt movements in zero-G invited questions, and questions invited overseers. "Take the paste and forget the alloy."

Olenka's loupes clicked as she dropped the second lens over her right eye. Her gaze remained fixed on his collar seal. "Monel-400 hasn't been cast since Year 12. The founding council bricked up those vents with three tons of basalt and plasma weld after the Great Radiator Surge. You didn't just crawl into a maintenance riser, Levmir. You opened a grave."

"The grave is choking the primary manifold," Levmir said, his tone flat. "If that return loop freezes solid, the thermal expansion will split the reactor sleeve. You won't have to worry about the overseers. You'll be breathing flash-frozen nitrogen before second shift."

She studied him through the heavy glass of her loupes. The silence between them was measured only by the rhythmic pinging of expanding steam in the Habitation Ring below. Finally, she unclipped the braided fluoropolymer hose from her belt ring and shoved the coiled line against his chest, along with the two stainless compression unions.

"If Kordov catches you with hardware from my bench, I'll tell him you stole it," she said.

"Fair enough," Levmir replied. "I'd do the same."

He backed out of her cubbyhole into the cold air of the junction pipe. Twenty-one hundred calories of high-protein paste was an extortionate rate for two meters of metal that wouldn't melt under pressure, but dying in the cold at least smelled better than boiling in a yeast vat. He didn't waste time looking for a proper workbench. He wedged his magnetic boots against the structural ribbing of Vent 12, laid out his tools on his magnetized thigh plate, and went to work on his suit's ruptured cooling loop.

His severed auxiliary umbilical hung limp, its torn edges jagged from his hasty cut in the plenum. Levmir took his tube cutter, scored the damaged neoprene back to clean material, and deburred the interior wall with the reaming blade of his multitool. He slid the stainless compression nut over the hose, followed by the tapered brass ferrule, aligning the bite edge exactly two millimeters from the lip.

He mated the braided fluoropolymer jumper to the primary circuit, sliding the male fitting into the receiving union. With two thin wrenches from his kit, he held the body stationary while torquing the nut one and a quarter turns past finger-tight. The stainless steel groaned, the ferrule swaging into the tubing wall to form a mechanical, metal-to-metal seal rated for twenty-five bar.

Levmir opened the suit's secondary coolant reservoir valve. Glycol surged into the new transparent loop. He watched the fluid closely under his helmet lamp. A few tiny nitrogen bubbles tumbled through the stream before getting caught in the suit's vortex separator. The digital pressure gauge beside his wrist registered six point eight bar. Stable. The internal heat sink temperature, which had climbed to a dangerous fifty-two degrees during his descent, began its slow drop back toward twenty.

He packed his tools, checked his lapel dosimeter, and kicked off the bulkhead.

His cold-gas thruster pack hissed softly in the vertical conduit. Zero-G transit was an exercise in momentum management; every burst of pressurized carbon dioxide expended precious mass, and every stray bounce off the rusted conduit walls risked pinging the acoustic sensors mounted every thirty meters along the trunk line. Levmir kept his body tucked, arms drawn close, gliding upward through the dark along the greasy guide rails.

He passed the sub-deck junctions without slowing. At the thirty-meter mark, he caught the lip of a conduit flange with his gloved hand to arrest his drift, waited eight seconds for the autonomous hull-sweeper drone's sensor cycle to clear the upper quadrant, then shoved off again.

At forty-five meters, the ambient air thinned to near vacuum. The station's environmental processors didn't bother circulating breathable atmosphere into the dead sectors. Ice crystals floated in loose clusters around the valve stems, catching the glare of his lamp like suspended glass.

Levmir reached the plasma-cut hatch seventy meters above the habitation deck.

The green-stained Monel bulkhead stood slightly ajar where he had left it, the chemical corrosion from his Spirka-yeast paste holding the melted seam open just wide enough for a suited man. His lapel dosimeter started chirping a rhythmic warning.

Forty-eight millisieverts per hour.

He slipped through the opening into the primary radiator plenum.

The vast chamber was silent, colder than the crawlways below. Frost coated every surface in thick, jagged blooms. The temporary thermal shunt he had rigged earlier was still humming—a single glowing artery of hot reactor glycol pulsing through the braided line into loop 4B. The pressure gauge on the shunt held steady at five point nine bar. Mash Vat Seven was still getting its heat.

Levmir didn't linger at the bypass. He followed the massive primary return pipe deeper into the unshielded hull section, where the conduit narrowed and penetrated the outer basalt shell of the asteroid. Here, where the radiator panels interfaced directly with the hard vacuum of deep space, the temperature plummeted toward eighty Kelvin.

His boots clattered against the Monel floor plates as he reached the main manifold junction.

The pipe here was four feet in diameter, wrapped in crumbling multi-layer insulation that had turned brittle from decades of cosmic rays. Levmir unlatched the heavy inspection viewport on the pipe's forward elbow, wiping away a crust of frozen hydrocarbons with his thumb.

He brought his lamp against the quartz window.

Inside, the pipe was choked completely. It wasn't an ice dam from frozen coolant. Packed tight against the internal flow vanes was a dense, petrified mass of organic fibers, woven together and locked in place by thick nodules of calcified bone.

Levmir stared through the thick glass, his breath fogging the corner of his visor. The blockage didn't just stop the heat. It filled the entire bore of the station's main artery, frozen solid under fifty years of silence.