Nessa Vale led the party forty paces down the narrow drainage tunnel that branched west from the pump chamber. The floor was ankle-deep in icy mountain water that ran over smooth quartz gravel. It smelled sharply of wet coal and stone lime.
At the end of the drift stood a heavy, soot-blackened iron door set into an arched brick frame. Above the top door beam, cast into the iron, were the words: Air-flow UPCAST Chimney pipe · LEVEL TWO Safety check PORTAL.
“This was the natural draft chimney built sixty years ago during the first sinking,” Nessa explained. She wiped the soot from the brass hinges. “It vents directly into the sub-floor of the main steam hoist house. If the surface fan is turning, the upward draft pulls fresh air down the central shaft and exhausts the coal smoke through this stack.”
Sile Rook set his shoulder against the iron door. With a heave of his huge chest, the rusted latch bar snapped with a metal snap. The door swung inward on grinding hinges.
A rush of cold, upward-rushing air struck them in the face—a brisk, eighty-mile-an-hour draft smelling of winter snow, wood smoke, and surface mountain pines. The air was clean, free of the damp stall of the deep pit.
