Down in the muddy trench beneath the eastern water chute, the water level had dropped twelve inches since the stop bell rang. That left behind a thick, slimy coat of gray river silt that clung to the knees of Eren Tal’s leather breeches. The air was cool now. But it still carried the heavy, choking silt stench of decaying river grass, mingled with the sharp tang of pipe lime washed down from the stonework joints and the acrid vinegar bite of copper green rust on the bronze valve studs.
Eren knelt on a double-thick hemlock plank bedded in the mud, holding Hal Rook’s brass measuring tongs in his left hand and his six-foot iron probe in his right. Beside him, Ada Morland was down on her knees with her pocket torch, shining the narrow beam of light into the dark cavity beneath the northern timber shoe. Bessa Marr stood two paces back on a dry stone ledge. Her grease-stained apron was tucked into her belt and her arms crossed tightly over her chest to control the trembling in her forearms.
‘Look into this void, Ada,’ Eren said, his voice echoing in the wet stone trench. He pushed the iron probe horizontally beneath the twelve-inch ash sleeper. The rod slid eighteen inches into empty darkness without striking anything harder than liquified silt. ‘The entire bed of river gravel has washed out into the lower pool. The sleeper is sitting on air. The only thing keeping this fourteen-ton cradle from dropping into…
