At the northern terminus of the lee-side hall, thirty paces beyond the third window embrasure, the passage came to an abrupt, violent dead end.
A massive collapse of overhead vaulting stonework had snapped away from the ceiling, dumping three tons of splintered limestone blocks, crushed roof tiles, and crushed lime mortar straight across the floor. The rockfall formed an impassable barricade seven feet high. It filled the gallery from wall to wall. Through the jagged gap in the ceiling above the debris, only a choked chimney of compacted subalpine shale, splintered pine timbers, and jagged dark rock boulders was visible, fully sealing the northern route.
Yseld climbed three feet up the rubble slope. She tested the balance of the stones with the iron point of her climbing staff.
“Dead fall,” the scout pronounced. He shook her head as a trickle of fine white lime dust cascaded down between her boots. “The keystone of this transverse arch gave way when the mountain shifted a century ago. Look at the angle of the fractured arch stones. They’re wedged under three tons of overburden. If we start pulling blocks from the bottom of this pile, the whole chimney will drop like gravel out of a hopper. We can’t go forward along the floor without burying ourselves alive.”
