Entry hall 428 was a stone-built mystery designed during the height of the First Epoch to baffle the senses of any intruder who relied upon sound or sight navigation.
The walls of the gallery did not run parallel. Instead, they curved in long, uneven curved arcs built from polished hard black rock, their surfaces ground to such a mirror-like finish that the beam of Yan Zhiqiu’s animal fat lantern reflected back and forth across the nave in an infinite, disorienting swirl of colors of amber blades. Overhead, the vaulting was twisted along its transverse axis, causing the keystones to spiral like the inside of a nautilus shell.
In this chamber, sound did not travel in straight lines.
When Qiao Ming whispered a word into the northern curve of the wall, the sound did not echo back to his ear. It traveled along the polished stone arc, crossed the nave fifty paces away, and emerged behind Yan Zhiqiu’s right shoulder with the startling clarity of a voice spoken through a speaking tube.
Qiao Ming stopped at the apex of the main curved curve, his bare feet planted firmly upon a broad circular flat stone slab carved from white crystal-clear pale limestone.
