The hinge of the seven hundred and fiftieth floodgate gave up its seal with the sound of an iron tooth breaking deep in an anvil.
It wasn’t a sudden tearing. For three hundred years of high wash and low ebb, the black glass leaves had rested against their dark rock rebates, held fast by hardened barnacle glue and the huge lateral weight of the second drowned stratum. Qiao Ming set his heel against the bronze purchase-lever and threw his weight downward. Then, the balance weights groaned within their lightless stone pockets forty arm-lengths overhead. A hairline of dark space opened between the slabs, breathing outward with a dry, stone chill that had nothing in common with the warm sea-salt water of the middle rows of stone pillars.
Qiao Ming planted his bare feet on the grooved drainage doorstep. The stone under his soles changed within the span of a single pace. Behind him lay the wet, familiar banded limestone of the lower avenues, slick with green sea-moss and warm from the heat plumes that rose through the bilge-chimney pipes of the keel. Ahead, across the bronze threshold of Entry hall 751, the floor was surfaced in dark, unpolished dolerite, coated in a fine, dry bloom of crystal-clear hoarfrost that crunched like crushed sea-salt beneath his naked tread.
