Down in the deep bedrock gallery beneath the High Sluice, Captain Kray and two town guards threw their entire weight against the massive iron wheel of the bypass valve. With a series of deep, screaming groans of bronze threads biting into ungreased bronze seats, the four-foot gate slammed down into its rebate, cutting off the flow to Sub-Vault Seven with a thunderous CLANG that rattled the stonework arches of the entire terrace.
The effect was instant and terrifying.
Deprived of its secret eighty-thousand-gallon relief bladder, the forty-eight thousand cubic feet of roaring river water backed up into the main headrace channel within two seconds. High on the belvedere, the emerald water shield didn’t rise gracefully into the air. It flared into a blinding, violent white bright glare that hissed like a nest of scalded vipers.
Deep beneath the marble paving, a sound began to rise. A high-pitched, piercing sound shriek that set every tooth on edge and shook through the marrow of the shinbones. It was the baked-clay trunk channel screaming under forty-seven pounds of pressure of trapped, unvented high-pressure thrust.
Pella Rook knelt instantly on the flat stone slabs. Her ear was pressed to Hal Rook’s tone check rod. ‘Two hundred and forty cycles!’ Pella shouted to Korr Var over the ear-splitting whine. ‘The baked-clay is in deep ringing hum! The material can’t absorb the crushing force! It’s shaking three and a half inches out of posture!’
