By mid-afternoon, the low winter sun hung at a sharp forty-degree angle above the western peaks of the Iron Dragon Gap.
This was the optimal window Lin Tao had calculated. With the sun behind the mortal lines, the angle of incidence allowed the ten thousand concave mirrors to capture maximum solar light and funnel it directly into the forward sensor clusters of the Nine-Dragon Barrier. Across fifty li of trenches, squads of mortal craftsmen were completing the final sharp-angled posture of their mirror banks, tightening shift lugs and securing star-iron anchor cables.
Lin Tao walked along the low roof wall of Trench Sector 04, checking the sightlines with a brass sighting side.
Beside each mirror station stood two men. A tracker whose sole duty was to keep the curved plate tilted toward the sun. An worker whose hand rested upon the star-iron shutter lever. Mounted above each mirror was a small sighting tube made of rolled copper, fitted with crosshairs made of stretched spider silk soaked in shellac.
“Ensure the crosshairs are lined up with the intake cluster at the base of Dragon Pylon 01,” Lin Tao told the squad leader, an experienced Taiyi quarrymaster named Geng. “Don’t aim at the golden neck or the coiling tail. Look for the three dark quartz lenses embedded in the granite foundation ring.”
