The brass key was warm from Cale’s teeth and tasted of copper and salt, the same way it had tasted every cold morning for nine years when he carried his lantern up the Survey House steps before the senior auditors were awake and unlocked the lower filing presses with his chilblained thumb.
Kneeling on the bruised limestone at the base of the portable register stand, with the ozone stink of scorching oath-silver burning the inside of his nose and the flat clang-clang of the valley bells vibrating through his kneecaps, Cale fitted the key into the side cylinder of the brass casing. He knew this lock better than he knew the latch on his own rented room in Mere. Ossa Flint had built the outer housing to standard March Ledger vault tolerances: three heavy brass tumblers, a spring-loaded dust shutter, and a quarter-turn left before the right-hand throw released the maintenance plate over the anchor bus.
Cale pressed the shoulder of the key flush against the escutcheon and turned his wrist to the left.
The key did not turn.
It did not catch on grit or bind on a bent ward. Inside the brass barrel, a tiny secondary pin—an oath-silver check-lever wired straight to the register’s upper plate—dropped with a crisp, dead snick and locked the cylinder solid against his hand.
