The transition from cold war to kinetic conflict began not with a roar, but with a rhythmic, mechanical pounding from the southern peaks. The Sun-Guard had arrived, and they hadn't come with the ceremonial bronze of the capital. They brought the Imperial Siege-Train—massive, smooth-bore cannons hauled by teams of twenty oxen, their barrels glinting with the oily sheen of Alchemical Steel.
Deacon stood on the newly reinforced battlements of the Southern Pass, his "Logistical Insight" mapping the trajectory of the enemy batteries. He had spent the last week transforming the canal's hydraulic infrastructure into a defensive line. The water-towers were now armored redoubts, and the high-pressure steam lines had been diverted to the forward trenches.
"They're out of range for traditional crossbows," Julian said, his voice tight as he watched the Imperial engineers start to entrench their positions. "If they start a bombardment, they'll collapse the entrance to the Cleft before we can even get a train out."
"They aren't the only ones with long-range physics," Deacon replied. He signaled to the crew of the Mk I 'Vapor-Gonne'.
The Vapor-Gonne was an extrapolation of the "Steam-Blowoff" technology Deacon had used to clear the tracks. It consisted of a twenty-foot iron barrel connected to a subterranean high-pressure reservoir fed directly by the Deep-Pulse. Instead of volatile black powder, it used the sudden, explosive expansion of 250-psi steam to propel a thirty-pound lead sabot.
"Target the ox-pens," Deacon commanded. "We don't need to kill the men; we just need to break their logistics."
The discharge of the steam cannon was a sound unlike any gunpowder blast—a high-pitched, metallic crack followed by a deafening, prolonged hiss that obscured the valley in a fog of white vapor. The lead sabot tore through the air with a supersonic shriek, slamming into the Imperial supply lines with the force of a falling star. The Imperial ranks broke in a panic, their horses and oxen scattering as the ground itself seemed to erupt in steam.
The response from the Imperial line was immediate. The Lord High Steward, observing from a silk-draped command tent on the ridge, ordered the first salvo. The heavy siege guns boomed, the iron balls smashing into the Oakhaven basalt. The "gritty realism" of the siege set in instantly: stone splinters became as lethal as the shot itself, and the air was filled with the acrid smell of ozone and pulverized rock.
"The pressure in the reservoir is dropping!" Miller shouted from the trench, his face caked in grey dust. "We're drawing more steam than the well-head can stabilize! If we keep firing the Gonnes, the 'Deadman's Valve' might trigger a back-pressure surge!"
"Override the safety-shunts!" Deacon ordered, his hands steady on the range-finder. "If we don't hold them at the ridge, it won't matter if the well-head survives."
For twelve hours, the "Siege of the Siphon" was a stalemate of pressure versus powder. The Sun-Guard couldn't advance against the relentless, high-velocity steam-fire, but the Oakhaven walls were slowly being reduced to rubble by the Imperial weight of fire. The "Logistical Insight" warned Deacon of a dwindling supply of lead sabots and a rising heat-signature in the lower shafts that suggested the tectonic layers were reaching a critical state.
As the sun began to set, casting long, bloody shadows across the valley, a white flag appeared from the Imperial lines. A single rider approached the Oakhaven gate—the Lord High Steward himself, flanked by two unarmed heralds.
Deacon met him at the ruined portcullis. He looked like a man who had been living in a forge—his skin was soot-stained, his eyes bloodshot, and his hand never left the brass handle of the portable "Deadman's Trigger" wired to his belt.
"You've turned my Empire's grain-store into a slaughterhouse, Lord Cassian," the Steward said, his horse shifting nervously as steam hissed from a nearby vent. "You have proven that you can hold the mountain. But for how long? My engineers tell me your well-head is screaming. You're holding a lightning bolt by the tail."
"And if I let go, the lightning kills us both," Deacon replied. "I have the charges set, Steward. One twist of this handle, and the geothermal siphon collapses, the foundries are buried, and your 'Shadow-Rail' becomes a useless line of scrap metal. You want the power? You have to let us keep the pulse."
The Steward looked at the "Deadman's Trigger," then at the smoke rising from the Oakhaven foundries. He saw a man who wasn't bluffing—a man who had standardized time and iron, and was now prepared to standardize death.
"A compromise, then," the Steward said, his voice dropping to a whisper. "The Empire will recognize Oakhaven as a 'Sovereign Industrial Protectorate.' You keep your internal laws, your 'Labor Notes,' and your 'Standard Time.' But in exchange, the 'Deep-Pulse' is shared. You will build a dedicated high-pressure line directly to the Capital's works, and you will oversee the 'Imperial Standardization' of the Southern Rails."
"I keep the valves," Deacon countered. "The main shut-off stays in my command center. If a single Sun-Guard crosses the Oakhaven border without a trade-permit, I cut the flow."
The Steward stared at Deacon for a long, silent minute. The wind wailed through the basalt Cleft, carrying the smell of sulfur and smoke. It was a peace forged in terror, a "Cold War" of steam that would define the next century of the Empire.
"Agreed," the Steward said, reaching out a gloved hand. "Welcome to the table of Great Powers, Lord Cassian. I hope you enjoy the view. It's a long way to fall."
As the Imperial siege-train began to withdraw, Miller and Julian joined Deacon on the ramparts. The valley was scarred, the canal was chipped, and the people were exhausted. But the "Oakhaven Standard" had survived its first true test of fire.
"We won," Miller breathed, leaning against a shattered parapet.
"No," Deacon said, looking at the brass handle in his hand. "We just became too dangerous to kill. Now we have to figure out how to live with the lightning."