Entry hall 404 was unlike any hall they had crossed in the lower reaches of the vessel. Here, the floor did not stretch flat and open, but was divided into nine sunken alleys by parallel rows of massive stone filing racks that rose twelve arm-lengths toward the coffered ceiling.
Each rack was carved from dense, iron-grey dark rock, grooved with thousands of narrow box-shaped slots. In these slots rested tens of thousands of square seals carved from white chalk-stone, gray soapstone, and semi-clear green glow-stone. Over the course of sixty hundred years, the slow leak of lime-heavy stone water through the ceiling joints had coated the racks in a glistening, crystal-clear rind of flowstone, binding many of the lower seals forever into their stone beds.
Qiao Ming moved down the central alley, his bare soles stepping carefully between patches of slippery hardened deposit. He held his lantern low, allowing the raking yellow light to catch the cut cleanly faces of the seals that remained exposed above the stone floor. At every step, his bare feet registered the minute heat gradations of the flags. The dark rock was coldest near the drainage gullies where underground water trickled, and slightly warmer near the center of the nave where the foundation heat of the dormant engines radiated through fifty feet of solid rock.
