The access ladder to the third staging tier was built of split ash rungs lashed to hemlock poles with tarred hemp twine. It creaked under Pella’s boots as she climbed, each step sending a small shower of dry hemlock bark down into the gray mud below.
When she hauled herself onto the upper deck, the air was ten degrees warmer than in the trench. The heat radiated directly from the cast-iron belly of the bypass valve. It smelled of burnt metal tube oil, hot graphite, and the sharp, vinegar tang of scale dissolving under acidic river water. The deck boards under her feet were wet with condensated steam, slick as lard. It shook with an unsettling, high-hum shudder that rattled the brass buckles on her apron.
Bessa Marr was kneeling beside the valve gland with her leather tool roll spread open on a dry scrap of wool. Her young apprentice, Joril—a seventeen-year-old boy whose family operated the animal fat-rendering vats in Lowbank—was sitting on an upturned grease bucket. He held a five-pound copper-headed mallet with both hands. His face was pale beneath a smear of chimney soot. His eyes were wide and fixed on the trembling bronze spindle.
“Look at the weighted drop-line,” Bessa said as Pella pulled herself upright against the guardrail.
