The retreat of the fifty-first tide revealed a shadow in the eastern wall that did not match the blueprints.
Qiao Ming was surveying the drainage piers of Entry hall 312, three hundred paces north of the Great Iron Arch, his bare feet sliding across the wet banded limestone flags. The water had pulled back to the second terrace, leaving a thin film of grey silt and cold salt water in the recesses of the wall stone props. In the corner behind the fourth pier. There, the massive stonework met the ceiling arch, a narrow upright gap appeared—a fissure two spans wide that seemed to have been masked by a false skin of dressed limestone slabs.
He stopped, his lantern beam catching a dark streak of rusted lead running down the stone face.
Lead did not run down dry walls. In the stonework of the Ark, lead weeping was the signed name of an intentional seal. A joint where ancient builders had poured molten metal to lock a container or a doorway against the piercing acid of the deep ocean.
Qiao Ming set his work box upon a dry step and knelt before the fissure.
The opening was barely wide enough for a man’s shoulders. He squeezed his torso through the gap, his oilskin coat scraping against the rough banded limestone edges, and thrust his oil lamp into the darkness beyond.
