The sound did not come through the air. It came through the bedrock, traveling through thirty cubits of solid gray granite before it reached the soles of Jon Hale’s boots.
It began as a low, sickening thrum—a vibration so deep that it bypassed the ears entirely, vibrating inside the marrow of Jon’s shins and shaking the water droplets from his eyelashes. Then, with the sudden, concussive violence of an unvented quarry blast, the pressure relief channel forty feet below the cellar floor ruptured.
The three-inch iron inspection cover on the north flue blew off its four square studs with an ear-splitting crack of sheared metal.
The plate, fifty pounds of cast iron stamped with the King’s mark, shot upward like a mortar shell, smashing into the central cedar ceiling joist four feet above the table. The seasoned wood shattered with the sound of a falling oak in winter, raining splintered cedar laths and sixty years of soot down into the boiling violet brine.
A geyser of superheated steam erupted from the open flue hole.
It was not white like tea-kettle steam; it was translucent, shimmering with an invisible, blistering heat that instantly vaporized the dust in the air. The sulfurous reek that accompanied it hit Jon like a wet sheepskin soaked in burning brimstone, choking the breath in his windpipe and coating his tongue with the taste of copper slag and boiled vinegar.
