The victory at the estuary had proven that Oakhaven could repel a physical invasion, but the cost had revealed a structural weakness. The valley was an energy glutton. To keep the "Pressure-Gate" active and the "Glass-House" glowing, the geothermal siphon was being pushed to its thermal limit. Deacon knew that if the mountain ever "hushed"—or if the Empire managed to sabotage the deep-bore wells—the valley would freeze in its own shadow.
"We are balanced on a knife-edge of pressure, Miller," Deacon said, standing on the observation deck of the High Cleft. The wind here was a constant, predatory howl, a force that had been viewed by the locals for generations as a curse that stunted the trees and bit through the thickest wool. "We've been fighting the wind for years. It's time we put it on the payroll."
He introduced the blueprints for the Oakhaven Vertical Turbine. Unlike the picturesque wooden windmills of the Southern plains, these were industrial predators. Standing sixty feet tall, the turbines featured three curved blades of hollow, reinforced nickel-steel, designed to capture the high-velocity laminar flow of the mountain passes.
"The gear-box is the heart of the machine," Deacon explained, pointing to a complex assembly of planetary gears. "The wind is inconsistent, but our dynamos require a steady rotation. We'll use a Centrifugal Governor—just like on the steam engines—to feather the blades. If the wind picks up, the blades tilt to shed the load. If it drops, they bite deeper into the air."
The "gritty realism" of the Ridge-Line Project was a vertical nightmare. The basalt ridges were inaccessible to the heavy "Vindicator" trucks. Every ton of iron, every bag of slag-concrete, and every spool of copper wire had to be hauled up the cliffs using a system of steam-winches and precarious cable-ways. The workers, dubbed "Sky-Jacks," lived in hanging camps, lashed to the rock-face as the spring sleet tried to scour them off.
"We've got the first three foundations poured," Miller reported, his hands raw and calloused from the freezing cables. "But the 'Sky-Jacks' are seeing things in the fog, David. They say there are 'Giant Hawks' circling the peaks—birds that don't flap their wings and move against the wind."
Deacon didn't believe in myths; he believed in the Imperial "Logistical Insight." He realized the Lord High Steward had countered the Oakhaven Air-Corps with a specialty of his own: Alchemical Paragliders.
Launched from the high plateaus further south, these "Imperial Vultures" used silk-and-bone gliders treated with a lifting-gas to stay aloft for hours. They were silent, cold, and nearly invisible in the swirling mountain mists.
The first strike occurred at midnight. A "Sky-Jack" camp at Mile Marker 14 was decimated when a paraglider dropped a series of small, high-explosive "Fire-Eggs" into the winch-house. The cable-way snapped, sending two tons of turbine-shaft plunging into the ravine below.
"They're targeting the infrastructure, not the men," Julian said, looking at the twisted wreckage. "If they take out the winches, we can't finish the line. The turbines will just be iron skeletons on the ridge."
Deacon realized that to build in the sky, he had to defend the sky. He couldn't use the "Vindicator-Flyer" here; the turbulent mountain air would tear the fragile biplanes apart. He needed a Static Defense.
He introduced the Oakhaven Tesla-Mast.
Utilizing the excess "Spark" from the valley dynamos, Deacon erected a series of copper-tipped spires along the ridge-line. These were not weapons in the traditional sense; they were high-frequency induction towers. By pulsing the air around the construction sites with a massive electrical charge, he created a "Zone of Static."
The "gritty" reality for the Imperial gliders was a nightmare of physics. As they entered the "Static-Zone," the metal frames of their gliders began to hum and vibrate. The silk wings, treated with alchemical salts, acted as capacitors, building up a charge until blue "St. Elmo's Fire" began to arc across the bone-struts.
The Imperial pilots, suddenly illuminated by their own equipment and suffering from the disorienting effects of the electrical field on their nervous systems, found it impossible to aim. Two gliders were forced to ditch as their silk wings literally ignited from the static discharge.
"The ridge is glowing, David," Miller said, watching the violet arcs dance across the turbines. "It looks like we've crowned the mountain with lightning."
"It's a fence, Miller," Deacon replied. "A fence they can't cut."
With the "Lightning-Fence" active, the construction of the Ridge-Line was completed in record time. By the end of the month, twelve turbines were spinning in the Cleft, their rhythmic whoosh-whoosh-whoosh adding a new bass-note to the valley's industrial symphony.
The "Spark" was no longer dependent on the geothermal wells. The wind was now pumping power directly into the capacitor banks. Oakhaven had become the first city in the world to be powered by the very storms that tried to destroy it.
"We're energy-positive again," Julian reported, a smile finally breaking through his exhaustion. "The 'Glass-House' has more light than it knows what to do with, and the 'Pressure-Gate' is at full charge."
"But the Empire is watching the glow," Deacon said, his eyes on the southern horizon. "They've seen us tame the mountain and the wind. They know that as long as Oakhaven stands, the 'Imperial Way' is obsolete. They're going to stop trying to conquer us, Julian. They're going to try to Erase us."
"How?"
"The Solar-Mirror," Deacon said, pulling a grainy photographic plate from his desk. It showed a massive, reflective structure being built on the highest peak of the Southern Range. "The Steward is building a parabolic lens a mile wide. He's going to focus the sun's own energy into a beam that can melt our foundries from fifty miles away."