The tunnel connecting the drainage sump of Entry hall 983 to the lower gallery of Entry hall 984 had not been built for the passage of men. It was a high-pressure bypass channel, five arm-lengths wide and four arm-lengths tall, carved through the solid black dark rock of the Primordial Ark’s third transverse keel-rib during the reconstruction of the Second Epoch.
Here, the water had risen until only six inches of stale, stale air remained beneath the curved stone vault.
Qiao Ming swam on his side, his left cheek underwater to the temple in the freezing, violet-sheened fluid. His right hand reached ahead into the blind dark, his fingers lightly brushing the wet dark rock roof to gauge the clearance. At the same time, his bare feet kicked with slow, rhythmic strokes through the black settled mud resting upon the floor. The settled mud was eight inches deep, heavy as waterlogged lead-shot, gripping his heels with a persistent, sucking drag whenever his toes dipped too deep into the trough.
Behind him, Yan Zhiqiu swam in his slipstream. She moved on her back, her face turned up toward the stone ceiling, keeping her chin raised above the greasy knee pad. In the crook of her left arm, she held the Broken Slate pressed against her breast, keeping its engraved characters out of the dark water. Her right hand trailed behind her, feeling the coarse hair of Qiao Ming’s sounding line, which linked their belts together in the choking gloom.
