The narrow high walkway was three planks of seasoned hardwood suspended by cold-forged bronze stirrups eighteen deep-water lengths above the floor of Entry hall 516.
Down in the depths of the hall, the darkness was total. It was broken only by the intermittent green twinkle of eerie-glowing slime growing in the outer edge scum-gutters. Up here, near the springing line of the great transverse arches, the air was warm, heavy with the stone exhalations of the upper ballast tanks, and thick with the scent of wet iron and stone-hard kelp.
Qiao Ming walked the hardwood planks with a slow, flat-footed glide. His bare feet gripped the damp wood with easy familiarity. His toes curled over the plank edges to gauge the sway of the mid-air cables. Every ten paces, a bronze stirrup creaked—a dull, low-pitched groan that blended into the nonstop sound hum of the Ark’s internal air-flow chimney pipes.
Behind him, Yan Zhiqiu moved with careful care. She kept her balance point low, her right hand lightly brushing the cold stone face of the vaulting, the Broken Slate held securely against her chest by the crossed leather straps of her harness.
“Eight thousand four hundred metric tons of black silt,” Qiao Ming said, his voice a low shaking that barely carried beyond her ear. He stopped before a huge box-shaped structure of riveted bronze plates that bulged from the northern wall like the belly of a pregnant whale.
