The black horsehair cord, stretched across the green jade dais of Entry hall 886, became a channel of living sound memory.
Qiao Ming knelt on both knees upon the pale green jade, his bare feet anchored against the curb of the Heart-Vein Sluice. His rough, salt-calloused palms hovered an inch above the braided cord. He felt the intense, clear shaking that traveled along the horsehair fibers at thirty-two cycles per second. The sixty deep-water lengths of cord were not merely humming. They were singing with the ringing voices of forty leagues of dark water. It shook with the precise hum of every pool, drain tube, and weir he had measured over thirty years of solitary labor.
The cord itself was a masterwork of water-mapping craft. Harvested from thirty ages of high-sky mountain ponies bred to walk the wind-scoured ridges of the northern passes, the hair was dense, water-resistant, and entirely free of natural stretch. Each fathom had been tuned against a brass standard rod kept in a velvet-lined box by Old Master Lu, boiled in sheep fat to purge the trapped air, and braided by hand with three strands of waxed hemp running through the core. It had touched freezing salt water, fiery slurry, and hadal silt without rotting or stiffening. In the pitch-black cloisters where no lantern could burn due to damp foul-damp, his fingers had read the knots like words carved into wood.
