The first strike echoed off the upright limestone face of the upper quarry wall like a pistol shot.
Crack.
The impact was sharp, dry, and brittle. Under the steel metal ring of the ash rod, the crust of crystal-hardened salt and evaporated white chalk-stone shattered into a powder as fine as sifted flour. It sent white dust drifting across Kezra’s boots. But beneath the surface crunch, the shock wave traveled directly into her palms. A high-hum, stinging shaking that buzzed in the bones of her wrists.
Kezra held the rod motionless against the stone for three heartbeats, her eyes half-closed. She listened with her nerves rather than her ears. She kept her elbows relaxed, her shoulders loose. She remembered the hard-earned lessons her mother had beaten into her wrists behind the Kilnstep sheds. If a land-mapper tenses her forearms while sounding dense stone, the lengthwise sound shock wave bruises the wrist nerves within twenty strikes. Mountain ash had been chosen for sounding rods by ancient corpsmen for this exact property. Its straight, unbroken grain fibers sent sound waves at more than three thousand paces per second with minimal dampening.
Inside the calfskin pocket beneath her coat, the bonded notebook gave a faint, warm twitch against her ribs. On page thirty-eight, a thin level line of pale grey ink etched itself across the thick parchment, recording the first deep-rock stratum:
