The sound began as a dry, singing shaking in the roots of the teeth before it reached the ears. It rose through the soles of Qiao Ming’s bare feet, a steady, cyclic pulse that made the fine white chalk-stone silt on the flat stone slabs organize itself into fine, detailed sharp-angled ripples. Nested rings intersected by twelve streaming spokes spread across the dust, mirroring the sky chart engraved upon the backplate of his star compass.
“Hold your lantern steady,” Qiao Ming murmured, his hand catching Yan Zhiqiu’s elbow with gentle, unbending pressure. “Do not strike the brass frame against your belt. The pendants above us are tuned to the pitch of an iron hammer. If we excite their ringing node, fourteen tons of white spar-stone stalactites will drop like plumb-bobs into this passage.”
They stood at the entrance of Entry hall 458, a huge, narrow chimney pipe of dark hard black rock coarse grey rock that soared eighty arm-lengths into the ceiling gloom. Hanging from the zenith of the curved arch was an inverted forest of needle-sharp stone pendants, each six paces long and slender as an oarsman’s spear. Hundreds of years of stone water slow leak had coated them in a glass-smooth glaze of crystal-clear aragonite. The air currents rising from the lower drainage shafts whistled through the gaps between them, producing a faint, nonstop chord that hovered exactly at four hundred and thirty-two shakes per second.
