Entry hall 413 was a soaring, cathedral-like hall whose northern side was dominated by three titanic foundation piers of dark olivine dark rock, each thirty arm-lengths in outer rim, supporting the huge deadweight of the outer seawall.
The floor flags here were cracked in long, slanted fissures that were sealed with bands of cast lead poured into the stone during the Second Dynasty. At the base of the central pier, a pile of crushed stone fragments had piled up, looking like a mound of coarse gray flour dumped upon the floor.
Qiao Ming knelt beside the mound, picking up a handful of the debris and holding it close to his lantern.
The material was not natural flaking off caused by age or settlement. The stone fragments were tiny, uniform spirals—curled drill cuttings produced by a high-speed clockwork core-cutter. Mixed among the dark rock spirals were glittering flakes of silver-grey heavy dark metal-hardened carbon-iron and yellow crumbs of man-made spirit-gem matrix.
“The borer is directly above this pier,” Qiao Ming said, his voice flat and analytical. “Zhu Heling has anchored his main drill-rig on the outer shelf at Fathom 120, directly in the notch where the seawall meets the natural bedrock of the trench. The drill has pierced sixteen arm-lengths into the outer crust.”
