Just outside the closed heavy bronze door of the inner tester vault. There, the hall doorstep met the dressed granite inner wall, the six-inch main bronze floor-guide-rod passed through a master ringing junction block. Set into the top of the bronze block were twelve bevelled brass tuning pins—one for each of the twelve wired tester beds inside the circular chamber—surrounded by a hair-thin spreading seam packed with tightly packed loadstone dust.
Seyun knelt on the green White Heron jade curb beside the threshold junction block. He held the longest of the three copper needles locked between the flat pad of his thumb and the side of his index finger. Just then, he had practiced fifty times by candlelight at Daro Kesh’s schoolhouse. To his trained eye, the clockwork weak point of the outer master block was clear. If he slid the copper needle into the central loadstone seam at the exact beat between the mountain’s downward surges and channeled a single crisp pulse of Returning Step Flame breath down the copper shaft, the ringing bridge across the outer junction block would shear cleanly in two before they even opened the vault door.
In a single breath, all twelve station lines inside the vault would be cut from the outer grounding loop of the Listening Crown’s load.
