From the high iron narrow high walkway of Tier One, ninety feet above the floor of the Cauldron Vault, the spectacle unfolding below was beyond anything Tomas Reed had witnessed in nine years of cart hauling along the Great March.
What had begun as a thigh-thick jet through the pilot water chute had transformed into an uncontainable fiery eruption of water-pressure speed.
Seventy-four feet of trapped alpine lake—twenty thousand tons of water backed up across five square leagues of underground karst basins—punched through the loosened seam. The three-ton chert wedge was spit out of the water chute like a cherry pit, tumbling through the darkness to shatter against the far limestone wall with a sound that was instantly swallowed by the roar of the deluge.
And then, the true scour began.
The four heart-oak baulks that Tomas and Sile had jacked into place performed their heroic, load-bearing duty. As the crushing pressure exploded outward, the ceiling of the arch tried to settle into the void. The fourteen-inch oak posts groaned, their seasoned fibers compressing with gunshot-like creaks. But their lead-padded bedrock footings held true. The arch didn’t collapse. The ceiling didn’t cave in.
Instead, the entire striking force of the water was funneled directly into the four thousand two hundred tons of blasted rubble choking the throat.
