The floor under-road drains of Entry hall 522 were not drains; they were cannons charged with mud.
For six hundred years, the Upper Silt Cistern of the Fifth Tier had held eighty-four hundred tons of packed magnetic iron slurry under the dead water-pressure head of eighteen upright deep-water lengths. Qiao Ming tripped the four bronze release pawls along the high narrow high walkway. Then, that huge column of semi-liquid stone did not flow through the down-pipes with a gentle gurgle. It dropped like a falling monolith.
Down in the wide hall of Entry hall 522, an entire battery of six air-powered drills was preparing to breach the northern water-lock.
Twenty-four hired blades from the Iron Claw Brigade were laboring in the glare of portable acetylene torches. Their heavy bronze wrenches tightened the coupling collars of three-inch steam lines. everyone could feel the reek of unburned gas, hot valve-grease, and sweat. At the center of the battery stood a backup steam-boiler on iron wheels, its pressure gauge needle shivering against the red peg at two hundred and forty pounds of pressure.
“Give her another turn on the pipe hub!” the battery sergeant shouted, his visor pushed up, wiping grease from his stubbled chin. “The Scholar wants the water-lock pierced before the third bell! If the drill teeth dull, swap them out for the coarse diamond bits!”
