The lower toggle shoe of the water gate dropped into its relief position. Then, the sound terror inside Trunk Three broke like a lanced boil. The high, screaming whine of ringing bubbling blast died away within five seconds, replaced by the deep, thunderous, steady roar of forty thousand gallons a minute of scalding salt water venting cleanly down the granite tailrace toward the Gray Rush.
On the brass Bourdon gauge threaded into the inner wall sensing port, the iron needle fell back from the shattered glass over-stop. It swept counterclockwise past fifty, past thirty, past twenty, until it settled into a calm, rhythmic flutter at eight and a half pounds of pressure. The grey clouds of powdered pipe lime and dry mortar dust stopped raining from the arch crown, drawn outward toward the river mouth by the sudden draft of the rushing water.
Pella Rook stood up slowly on the wet ash planks of the staging platform, her knees stiff and aching from twenty minutes of crouching over the shaking ironwork. She wiped her face with a corner of her canvas apron. That left a smudge of black dark oak-ink across her cheekbone. Then it looked down at the exposed bronze breastplate of the bypass pipe hub that the dropping water level had just uncovered.
