The concussion from beneath the earth struck Jon Hale’s boots with the force of an iron ram driven into bedrock.
He sprinted off the bridge roadway, past the smoking granary walls and through the debris-strewn churchyard, his boots churning through yellow sulfur mud and shattered slate tiles. Behind him, Sir Cael Ardent was rallying the remaining town watch to hold the gatehouse barricade, but Jon knew the battle above was already an empty demonstration. The true fracture was beneath their feet.
Jon threw his mass against the iron cellar hatch behind the chapel garden, plunging down the spiral stone stair into the subterranean darkness.
The air in the well had become nearly unbreathable. A blinding, choking fog of pulverized limestone and acrid sulfur smoke rolled up the stone treads in thick, greasy billows, burning his eyes and searing his nostrils with the reek of exploded saltpeter. Coughing violently into the wool of his sleeve, Jon stumbled off the bottom step onto the masonry catwalk of the dry aqueduct.
Thirty yards ahead, the outer sluice portal was an inferno of yellow sulfur smoke, splintered oak, and rushing water.
The heavy outer timber sluice-gate—twelve inches of seasoned white oak reinforced with cross-braced wrought-iron straps—which Jon and Bram had wedged to seal the canal mouth against the river spate, had not held against the sappers’ counter-mining. The Ash Host had dragged two forty-pound powder casks through the outer drainage ditch, packing the iron-hooped kegs directly into the timber apron beneath the bottom sill…
