The Narrow Straits of Basalt formed the geographical and spirit throat of the entire second stratum.
Carved during the ancient era through a single huge intrusion of black metamorphic dark rock, the straits were three hundred paces long, sixty arm-lengths high, and barely eight paces wide. Along the upright black walls, polished smooth by ten thousand years of high-tide bores, ran narrow, slippery ledges no wider than a man’s palm, upon which the ancient water-scribes had walked to inspect the water registers.
At the eastern entrance of this narrow gorge, Zhu Heling had established his final sound castle.
Mounted upon a raised iron platform spanning the width of the deep gap sat the Grand Resonance Battery of the Obsidian Scroll hall: six huge bronze horns, each twenty arm-lengths long, connected by copper sound pipes to high-pressure spirit-coal compressors. Behind the horns stood two hundred elite fighters armed with heavy void-crossbows, their faces hidden behind dark iron visors.
“Hold the choke point!” Zhu Heling’s voice echoed through the brass horns from his distant command center atop the Celestial Sovereign, amplified into a harsh, metal rasp that rattled the loose gravel in the deep gap. “The Mapmaker must pass through the dark rock throat to reach the Hall of Ten Thousand Statues! If he steps into the straits, fire the nonstop sonic barrage! Pulverize the gorge with sound sour note!”
