The Welded Turnout

How many seconds remained before two hundred tons of armored steel struck five inches of solid thermite slag? Kyriakos stared at the vibrating glass of the telemetry monitor, his thumb pressing the refresh toggle as Locomotive 404 hammered down the elevated high-line viaduct.

Below them, the industrial sprawl of Halikarnas burned in sickly orange flares. The main line ran straight along the concrete causeway toward Junction Nine, where the high iron split. The left fork climbed toward the limestone quarry and safety; the right dropped into the marshaling yards beneath the low freight loop, where twelve unvented catalytic storage tanks sat like primed bombs.

The track sensor at the turnout frog showed a flat zero.

"Signal's dead because the cult burned the relay box with magnesium powder," Kyriakos shouted over the thrum of the diesel pistons. He braced his boots against the cab floor plates, pointing through the cracked forward viewport. "The turnout points are fused shut to the right. If we hit the frog at sixty miles an hour, the leading trucks will climb the rail and throw us four stories down into the catalytic battery."

Stathios stood braced against the iron brake stand, both hands locked around the master throttle. His grease-stained knuckles were gray with soot. "We don't have the stopping distance. If I throw the emergency shoes on this grade, the cryogenic cars behind us will accordion into our tender. We take the high line, or we take the pavement."

"Look out the starboard catwalk!" Pelagia called from the auxiliary gauge station. Her gloved hand wrenched the secondary steam bypass closed as she pointed through the reinforced side slit. "We have company on the parallel service rail."

Kyriakos leaned toward the slit. Two motorized maintenance speeders were surging out of the smoke on Track Seven, running parallel fifty feet below the elevated viaduct before the service grade rose to meet them. The speeders were stripped-down flatbed carts bolted with crude sheet iron and powered by unshielded industrial diesel compressors. Four cultists in rubberized acid-hoods manned each cart.

The lead speeder mounted a pneumatic rivet gun converted into a heavy harpoon launcher. A pressurized cylinder of unrefined benzene sat strapped directly above the exposed motor manifold.

"Directorate Sector Six maintenance gear," Kyriakos said, tracking their approach as the parallel track climbed the concrete ramp toward the junction. "They stole those rigs from the sulfur-stripping depot three months ago. That forward cart is carrying an open benzene tank with an unrated brass regulator."

"Can you hit the regulator?" Stathios bellowed, hauling on the horn lanyard to clear the viaduct apron.

Damathea had already unlatched the cab's rear hatch. The roar of wind and sulfur smoke tore through the steel compartment as she hauled her heavy anti-material rifle onto the external railing. Her shoulder absorbed the vibration of the tracks as she leveled the long barrel.

"Give me thirty seconds of stable deck," Damathea called over the rushing air. "The lead cart is swinging an incendiary grappler toward our tender trucks."

The cultist on the lead speeder cranked the winch, raising an iron claw linked to a thick braided steel cable. If that cable fouled the tender's axle assemblies, the friction would snap the flexible cryogenic seals and vent their liquid nitrogen into the open air.

"Aim two inches below the cart's forward axle box," Kyriakos called out, leaning halfway through the hatch to spot the lead. "The pressure line connects to a jury-rigged distributor without a flame arrestor. Hit the line, and the back-pressure blows the compressor."

Damathea fired.

The heavy tungsten slug tore through the sheet-iron shield of the lead speeder. A bright yellow fireball instantly erupted from the ruptured benzene line, consuming the cart's motor housing. The speeder flipped end over end against the concrete ballast, scattering twisted scrap and burning fuel across Track Seven.

The second speeder veered sharply to avoid the wreckage, but its crew brought up two pneumatic grease-guns converted to spray burning crude. Black, smoking arcs of flaming sludge splattered against Locomotive 404's starboard flank, hissing violently against the cold steel armor.

"They're trying to blind our forward viewport before we hit the turnout!" Pelagia shouted, checking the tender pressure dial. "The heat is radiating into the cryogenic manifold lines!"

"Pelagia, reroute the front de-icing injectors!" Kyriakos lunged across the cab to the pneumatic manifold board. He had memorized the Directorate's locomotive refit schematics during his infiltration of the refinery supply chain. He yanked the red locking pin from the secondary de-icing loop. "The winter de-icing nozzles on the cowcatcher are connected directly to the primary steam header. If we feed liquid nitrogen through the de-icing bypass, the front nozzles will fire a sub-zero jet directly at the track bed."

Stathios glanced back from the throttle, his jaw set in a hard line. "Thermal shock on hot thermite?"

"It will vitrify the slag," Kyriakos said. "Molten thermite cools into brittle iron-aluminum oxide. Freeze it instantly, and the cowcatcher's steel wedge will shatter the weld like rotten ice."

"Do it," Stathios barked, leaning his hip against the throttle to free his right arm. "Five hundred paces to the switch!" He grabbed the primary cryogenic feed wheel on the cab bulkhead, spinning it four full turns counter-clockwise. A deep, hollow clunk echoed beneath the floorboards as the liquid nitrogen surged from the tender into the forward piping. The temperature gauge dropped past minus two hundred degrees within three heartbeats, frosting the copper pipe fittings in dense white rime.

The second cult speeder pulled abreast of the cab, an acid-hooded figure raising a cutting torch to sever the exterior cryogenic conduit.

Damathea cycled the heavy rifle's bolt, sending an empty shell casing clattering across the iron plates. She fired a single round through the cultist's torso, punching him clean off the speeder deck. The driverless cart lost its steering linkage, slammed into the viaduct's concrete parapet, and plunged four stories into the refinery marshaling yards below.

"Two hundred paces!" Stathios yelled, planting both boots and leaning his full weight onto the throttle bar. The massive locomotive surged forward, its steel wheels screaming against the rails as the engine hit maximum boiler speed.

Ahead in the darkness, the turnout frog of Junction Nine gleamed with the dull, smoking red lump of hardened thermite weld. The slag blocked the left rail points, threatening to jump the wheel flanges and derail the entire train.

"Now, Kyriakos!" Pelagia yelled.

Kyriakos threw the auxiliary de-icing lever to maximum discharge.

A roaring curtain of pressurized, sub-zero liquid nitrogen blasted from the twin nozzles beneath the cowcatcher. The white, foggy plume struck the glowing thermite weld three seconds before impact. The air exploded with a deafening crackle as the superheated metal met minus-three-hundred-degree liquid. Billowing clouds of frozen vapor enveloped the front of the locomotive.

Locomotive 404's heavy steel cowcatcher slammed into the frozen obstruction.

The brittle slag shattered into thousands of harmless gray shards, spraying across the ballast like gravel. The locomotive's left flange caught the switch rail with a jarring shriek of protesting steel. The entire cab lurched violently to the left, throwing Kyriakos against the brass valve housing as the heavy trucks bit into the high-line track and held.

The locomotive held the high grade, clearing the junction and leaving the low storage tanks far below.

"Track switch held!" Pelagia gasped, catching her breath as she shut the de-icing valve to conserve the nitrogen reserves. "We're on the high line to the quarry."

Stathios eased the throttle by two notches to settle the surging boiler pressure. "Good eyes, Inspector. The Directorate taught you something useful after all."

Before Kyriakos could answer, the entire viaduct shuddered beneath a violent impact from above.

A deafening crash caved in the reinforced steel roof plates of the trailing cryogenic tender. Ten tons of viscous, oily mass slammed onto the tank car, shaking the locomotive to its frame. Through the observation slit, Kyriakos saw four-foot talons of congealed black tar tearing through the outer armor plate, hungry for the cold liquid within.

Damathea stepped back into the cab, slamming the heavy breech of her rifle shut and locking her eyes onto Kyriakos. "Stathios, keep this engine rolling. Kyriakos, we have three seconds before those claws breach the tender dome. You want to vent the tank to freeze it, or do I blow the roof hatch and put a slug in its core?"

Kyriakos looked from the screaming pressure gauge to the heavy red bypass handle in his grip. The choice would cost them half their cryogenic payload or Damathea's life on the open catwalk.

"We vent," Kyriakos said, his fingers locking around the iron release.