The water at the bottom of Tank One was clear enough to count the scratches in the stainless steel.
Julian leaned over the rim of the butterfly tub. Below the surface, four heavy hexagonal bolts held a ten-inch circular steel plate across the main drain hub. A dark bead of asphalt sealant was smeared around the rim of the plate, keeping the cavity underneath completely watertight.
“Mac,” Julian said. “Bring the one-point-five-inch socket.”
“Already got it off the belt, Kid,” Mac said.
Mac stepped up to the edge of the tub. His prosthetic left arm gave a quiet hydraulic hiss as he rotated the wrist assembly, locking the heavy 1924 naval brass spanner onto the drive socket. He rolled up his right sleeve, leaning over the rim with his boots braced wide against the wet tiles.
“Watch the torque on those threads,” Dr. Corvo said, standing behind Dr. Hahn’s wheelchair.
He was wrapping a warm gauze dressing around the old woman’s left wrist, where the plastic commitment band had left a pale indentation in the skin. “That plate was torqued down thirty years ago in high-saline water. The galvanic corrosion could shear the bolt heads if you rush it.”
“I don’t rush brass,” Mac grunted. “My father worked naval yards. If you force a cold thread, you buy the whole manifold.”
