The soothing hum of the flywheel died away as they passed through the double iron airlocks of Entry hall 680. Here, at the lowest drainage confluence of the Ashen Epoch, the air was dark, cold, and heavy with the bitter smell of put out fires and calcined bone. This was the Central Sump of the Foundries—the underground deep pit into which forty entry halls had emptied their waste, their melted rock waste, and their final secrets.
The chamber was a huge upright pit eighty arm-lengths in width. It was surrounded by five tiers of cantilevered iron walkways that clung to the circular dark rock wall like the work frames of an abandoned mine. Open mouths of giant stone drainage water chutes opened into the pit at every tier, their iron grates choked with twisted scrap, frozen melted rock waste stalactites, and dried drift-silt.
Qiao Ming walked to the edge of the lowest narrow high walkway, his bare calloused feet testing the rusted iron grating. The metal sagged slightly under his weight, groaning with a dry, metal creak that sent echoes tumbling down into the lightless shaft. He knelt, hooking his prehensile toes through the diamond mesh to anchor himself, and looked down over the lip.
