Inside the third horse stall of the River Lantern livery, the two heavy black Chancellery warhorses had been backed out of the stall and tied short to the iron hay-rings in the center aisle so their hooves would not trample the floor planks. Against the left partition wall sat the two triple-buckled leather saddle-panniers that Senior Guard Keld had claimed contained court assay weights—their brass padlocks hanging open, their copper-lined interiors completely empty save for crumpled packing straw and the sharp, vinegary reek of alchemical nitric paste.
Jon Hale knelt in the bedding straw at the rear of the stall, directly beneath the wooden manger, and laid both scarred palms flat against the wide, two-inch-thick oak floor planks.
Through House Memory—the quiet domestic sense by which a Keeper of the Hearth knew every settled joist, mouse-run, and loose slate inside his four cornerstones—the geometry of the earth beneath the stable opened in Jon’s mind like a carpenter’s cross-section drawing.
When his great-grandfather had built the five-stall livery barn against the west wall of the River Lantern, the masons had laid the main oak floor-sleepers over a dry six-foot bed of coarse river sand and pea-gravel that filled the trench of an abandoned pre-imperial culvert. That ancient culvert ran straight under the courtyard cobbles and abutted the massive dressed-granite foundation pier of the inn’s cellar vault—the exact pier into whose inner bedrock face the Hearth Nail had been driven.
