Fifty paces behind the inhabited bunks of the western drift, the domestic warmth of hearth smoke and boiled turnips gave way entirely to the bitter, metal chill of the mountain’s inside. Here, the limestone roof sloped sharply downward, shored by three in a row sets of massive squared oak timbers. Each timber baulk was a full twelve inches thick, blackened by age and damp, held in place by doubled wedges of seasoned mountain ash driven between the caps and the bedrock.
Kezra Venn knelt at the base of the easternmost timber set, her gloved fingers resting on the rock doorstep. Beside her, Garn held his brass mining lantern low so that its beam played across the face where the grey, bedded limestone ended in a violent, jagged shear.
Across an upright width of six paces, the rock was no longer stone at all. It was a dense, slanted band of dark, soapy clay gouge and crushed chlorite flaky rock, ground to the consistency of greasy graphite by hundreds of years of underground movement. The shear plane dipped southward at a steep sixty-degree angle, cutting straight down into the mountain root toward the unseen 512-pace base of the benchmark stone base.
