When the three burning oak floorboards tore loose from their four-inch wrought-iron spikes and slammed upside down onto the stones beside the kitchen table, a column of dry, superheated air and glowing soot belched straight up out of the four-foot hole in the center of the floor.
Alden Bram did not step back from the rim.
For forty years he had worked lime-kilns, foundry hearths, and deep bridge foundations along the river valley, and he knew the exact difference between an ordinary wood fire that wanted water and a white-hot masonry flue that would explode like a mortar shell if a man threw cold well-water into its throat.
Holding his six-foot iron crowbar across his chest like a guard-rail, Bram leaned half a step over the blackened heart-pine cross-joists and looked straight down into the smoking chasm under the River Lantern’s kitchen.
Two feet below the charred underside of the floor joists—directly above the stone haunch of the north cellar arch where Bessa Karr’s forty firkins of mutton tallow were stacked—ran an old, unmapped twelve-inch square conduit built of hard-fired red river brick. It was not part of the inn’s original domestic chimney at all. Bram recognized the herringbone coursework and the grey vitrified slag-mortar instantly: it was an auxiliary pressure-bleed sleeve laid down two hundred years ago by the Crown builders to connect the outer aqueduct ring to the Hearth Nail vault below.
