Ada Morland stepped out of the shimmering oval into Sister Merrow’s washroom, right away clicked the side button on her digital stopwatch. Then she looked down at her heavy rubberized bib overalls. The air in the washroom was thick with sulfur smoke, boiled tea, and vinegar, but Ada didn’t waste a second complaining about the smell. She carried her heavy canvas technician’s tool roll under one arm, her four-dial brass pressure pipe hub in her left hand. A clean thermos flask tucked into her chest pocket.
‘Work order logged,’ Ada said briskly, nodding to Pella. ‘Twenty minutes on the clock, two silver coins checked in locked deposit. Where is this flooded cellar?’
‘Three doors down the lane,’ Pella said. She handed her a pair of thick oiled-reed gauntlets Dima had finished an hour earlier. ‘The Nine Lanterns. Tenement boarding house. The coal bunker is collapsing, and hot foam is blowing through the floor joints.’
‘Right then. Let’s look at the plumbing,’ Ada said. She stepped through the kitchen door into the cold Lowbank rain without a flinch. She had spent thirty years wading through flooded basements in Yorkshire. Rain in an alternate world was just wet water falling from gray clouds.
They hurried down the narrow alley, Eren walking ahead with a blazing pitch torch and his ash pry bar. The ground beneath their feet was sodden with gray river mud and rime-crusted deposits of white pipe lime that had washed out of foundation fissures. They entered the basement entry of the Nine Lanterns. Then, Ada paused on the landing, sniffed the billowing steam. Then she pulled a small glass vial and a brass drift from her breast pocket.
‘High white lime-chalk,’ Ada noted, shining her headlamp through the dense fog. ‘Smells like hot hard pipe-crust mixed with stale river silt. Your river has dissolved limestone beds upstream, hasn’t it?’
‘The Great Sluice is cut through limestone bluffs,’ Pella confirmed, following her down the slippery stone steps. ‘My father used to say the river carried enough lime to plaster every ceiling in Lathmere.’
The cellar floor was a disaster. Four inches of frothing yellow foam covered the flat stone slabs, swirling in warm, greasy eddies around half-sunk wooden crates and rotting potatoes. At the far end of the vault, beneath a massive brick arch that supported the tenement’s central chimney, ten tons of black coal had settled into a sodden, smoking heap. Water was gushing from beneath the coal bunker with a steady, hollow roar.
The stonework walls were ancient, built of rough-dressed sandstone blocks laid with crumbling river mortar. Patches of dark green moss hung from the mortar joints, and in the corners where the floor met the bedrock, the clear copper green rust of underwater bronze drain fittings gleamed through the murky water.
Ada stepped straight into the warm foam without pause. Her heavy steel-toed rubber work boots gave her solid purchase on the slippery stones. She unrolled her canvas kit on top of an upturned iron oil drum. She laid out her hardened steel packing hooks, brass drift punches, and a heavy copper-headed dead-blow mallet.
‘Hold that torch higher, Eren,’ Ada commanded, wading toward the roar of water behind the coal bunker. ‘I need light on the invert level. Where does this floor drain discharge?’
Eren held the torch forward. Its smoky yellow glare reflected off the swirling foam and wet stonework. ‘There was an old stone catch-basin built into the bedrock forty years ago. It’s supposed to connect to the public harbor relief under-road drain.’
Ada reached the back wall. Behind the collapsed coal, half-buried under crushed hard coal and black sludge, a massive circular opening yawned in the foundation stonework. It was an ancient twenty-four-inch cast-iron pipe collar, bolted to the stone with rusted square-headed studs. Inside the collar, a heavy cast-iron flap valve hung on a massive bronze pivot pin.
Under normal running conditions, a flap valve was a simple, elegant piece of non-return building. River water could push it shut from the outside during a high tide, while wastewater from the cellar could push it open from the inside. Just then, the cellar filled. It relied entirely on gravity and differential head.
Ada leaned into the opening, wiping steam from her safety goggles with a wet glove. She pulled a flat grease pencil from her pocket and made three chalk marks on the collar pipe rim to measure the shifted weight angle. Then she tapped the cast-iron casing with her brass drift. A dull, dead clunk echoed through the pipe—no ringing deep ring, no metal clearance.
‘Well, look at this bloody mess,’ Ada muttered, her Yorkshire accent cutting through the roar of water. ‘Look at that flap.’
Pella squeezed between the coal pile and the wall, holding her lantern close. The iron flap, three inches thick and weighing at least eighty pounds, was wedged wide open at a sixty-degree angle. Jammed solidly beneath its lower sealing lip was a massive wedge of compacted boiler clinker, coal dust, river gravel, and decomposed reed roots.
The silt stench rising from the opening was overwhelming. It carried the rank, choking odor of anaerobic river mud baked under boiling pressure. Every five seconds, a surge of gray slurry pulsed around the blocked path. It sent hot foam slapping against Ada’s bib overalls.
The flap was jammed open. Because of that, the high-pressure overflow from the College’s deep drain tube was not draining into the harbor under-road drain. It was reversing. Five thousand gallons of scalding, high-pressure river salt water were roaring backward through the public relief under-road drain, blowing past the jammed flap, and erupting directly into Master Orv’s basement.
‘It’s a backflow geyser,’ Pella whispered, shielding her eyes from the sulfur spray. ‘The flap is fully frozen.’
‘Not frozen,’ Ada said, tapping the bronze pivot pin. ‘Wedged. Some idiot upstairs has been shoveling boiler sweepings into this floor drain for twenty years to save the cost of an ash carter. The grit washed down, hit the flap seating, and when the backing-up pressure surged last night, it rammed the whole mess into the hinge like set concrete.’
Ada leaned closer, her flashlight beam cutting through the yellow foam to inspect the bronze seating ring. The metal was pitted and scored with deep gouges where sharp quartz gravel had ground against the machined surface under high speed.
‘Look at that bronze,’ Ada said, running a gloved finger along the lip. ‘Bubbling blast pitting. That water isn’t just flowing. It’s boiling under negative pressure before it hits this collar. That tells me the blocked path upstream is running at critical speed.’
She pointed her brass drift into the dark throat behind the valve. ‘See that swirl pattern in the silt? The water is spiraling at forty revolutions a minute. That means there’s an elbow thirty feet back that’s partially obstructed. When liquid spins through an elbow under high head, it creates a nearby empty pocket bubble. When the bubble collapses, it eats the metal right out of the casting.’
Above their heads, the heavy oak ceiling timbers creaked under the weight of the water-soaked floorboards. Eren pointed his torch upward, inspecting the joints where the beams rested on the stone wall-brackets. ‘The steam is piercing the end-grain, Ada. If the cellar stays at ninety degrees for another forty-eight hours, dry rot will set into the tenons. The parlor stove above will drop straight through the ceiling.’
Tavi stood at the base of the stairs. He grabbed an iron bucket and watched the water line swirl around his ankles. He had scavenged an old broom handle from the yard to measure the depth against the bottom step. ‘It’s up another half-inch since we walked down, Pella! If it reaches the third step, it gets into the coal chute!’
Ada checked the collar studs. Two of the four iron bolts had rusted down to pencil-thin waists, coated in thick flakes of iron oxide. If they applied uneven torque to the hinge, there was a severe risk of shearing the studs entirely. They dropped the whole collar into the under-road drain.
‘If those studs shear,’ Ada told Eren, ‘we won’t just have a leak. We’ll have a two-foot open breach straight into the river under-road drain. Then your whole building drops into the harbor in ten minutes. We have to baby that hinge.’
Ada looked down at her stopwatch. Eleven minutes and thirty seconds leftover. The digital display blinked with steady, indifferent care.
‘Right,’ Ada said, pulling a two-foot hardened steel packing hook from her belt. ‘We don’t need magic, girl. We need leverage, elbow grease, and a bucket to catch the clinker. Eren, bring that pry bar over here, and don’t stand in front of the opening. When this flap breaks free, eighty pounds of cast iron are going to drop like a guillotine.’