The mud gave up its moisture easily enough. But the stone had no intention of moving.
Three miles south of the riverport, the great drainage ditch came to an abrupt, unbending halt.
Rising out of the black peat like the curved rib of a buried giant beast was a wall of pale grey quartz-hard speckled rock, twenty-two feet tall and forty yards thick.
Behind it lay the prize Giles Croft had mapped from the datum lines: the Sunken Basin.
It was fifty acres of stale, iron-choked depression. The water there didn’t flow.
It festered under a skin of rainbow-bright green scum, fed by deep underground fissures and locked behind the natural granite barrier. Beneath that oily water lay four feet of solid, unmined bog-iron ore, rich enough to feed three blast furnaces for five years.
Master Duncan Stone-Splitter knelt at the foot of the dyke, his heavy steel splitting wedge set against a natural fault line in the stone.
He spat on his calloused hands, took a wide stance. Then he swung his eight-pound sledgehammer with a grunt that shook his thick shoulders.
CLANG.
A shower of white sparks sprayed across the dry peat. The sledge bounced off the steel wedge as if Duncan had struck a block of solid anvil iron.
Duncan dropped the hammer, swore under his breath. Then it rubbed his aching palms against his grease-stained leather apron.
“Quartz-hard speckled rock,” Duncan growled. “Tougher than dragon tooth. It’s got seventy percent quartz dust in the matrix and zero natural bedding planes. Even with cold-rolled steel feathers, you’d break forty chisels before you cut a thumb’s width.”
Giles Croft stood on the crest of the canal levee, adjusting the knurled bronze focus ring on his sighting scope.
“Crushing strength is around twenty-eight thousand pounds of pressure,” Giles said mildly. “Standard igneous intrusion.”
Duncan looked up, squinting through a curtain of grey dust.
“A dwarven legion with black powder barrels couldn’t breach this dyke before midwinter. It would take six months of nonstop hammer work and twenty tons of powder just to cut a ten-foot notch for the water to drain.”
“We don’t have six months,” Giles said. “And black powder is too valuable to waste on rock that has done nothing worse than exist.”
“Then the iron stays drowned,” Duncan said, kicking the base of the ridge.
“The mountain god put this wall here to keep the swamp’s teeth behind a gate. You can’t argue with thirty thousand tons of living granite.”
Giles folded his wooden ruler with a sharp, dry snap. “The mountain god didn’t build this wall.
A fiery fissure cooled during the late earth-shaking uplift. That left a resistant dike while the surrounding shale eroded away. It’s a textbook deep-rock unconformity. And who said anything about cutting through it?”
Lady Millicent Croft walked along the dry timber narrow high walkway. Her thick parchment tally-book was held firmly under her arm. A pair of silver-rimmed glasses hung from a black cord around her neck.
“If we can’t cut the stone,” Millicent said, stopping beside Duncan, “then forty laborers have been hauling gravel for three days without a taxable yield.
The colony’s bacon ration can’t sustain sixty men swinging hammers at an unmoving cliff, Giles.”
“Nobody is swinging hammers tomorrow, Millicent,” Giles replied. “The hammers were an exploratory test.”
“A test that cost us three broken chisels,” Duncan muttered.
“Charge the steel to developmental depreciation,” Giles said without blinking. “Where is the pipe inventory?”
Millicent flipped open her tally-book with a crisp flick of her wrist.
“In the south warehouse, we have eighty lengths of eight-inch seamless copper tubing, salvaged from the old distillery works and Borin’s surplus casing billets. We also have forty pounds of tin-lead solder, twelve bronze gate valves, and three kegs of pine rosin.”
“That’s more than enough,” Giles said.
Toby Karr scrambled up the slope of the dyke, clutching a bundle of red-painted cedar stakes. His boots were caked in sticky red iron sludge from the lower digging cut.
“The water in the basin is rising, Lord Giles,” Toby panted. He wiped his forehead with his sleeve.
“The southern springs are feeding it faster than the dredge can run off the margins. Mistress Pippa took a sample from the center pool.”
Mistress Pippa the Fermenter was already trudging along the foot of the ridge. She held a glass test phial with long brass tongs. She wore a stained wool shawl tied over her mouth and nose.
“It’s sour,” Pippa said, holding the phial up to the pale afternoon light. The broth inside was a turbid, yellow-green liquid that clung to the glass like curdled milk.
“The sulfur is rising from the deep vents. But that isn’t the worst of it. Look at the settled mud.”
Giles took the tongs and inspected the phial. Tiny, thread-like filaments were drifting through the cloudy water, pale green and twitching with an unnatural, sluggish pulse.
“Organic spore contamination,” Giles muttered. “Necro-fungal mycelium.
The stale basin has created an ideal anaerobic culture vat. If that water stays trapped behind this ridge, the surrounding heat will ferment the entire fifty acres into a living hazard zone.”
Chieftain Torvald Dune-Strider walked the crest of the granite ridge. His copper-tipped willow wands were held flat before him.
The wands didn’t twitch. They bowed downward toward the basin, their tips trembling wildly against the rock.
“The Rot-Mother’s breath,” Torvald murmured, his hawk-like face darkening. “The old marsh tribes speak of the green sleep that comes when the water turns thick.
Any hunter who sleeps within sight of this basin doesn’t wake. His lungs sprout moss by sunrise.”
“Anaerobic fermentation produces methane and hydrogen sulfide,” Giles corrected, handing the phial back to Pippa.
“Neither of which needs a holy explanation. It simply means our workforce will suffer a severe productivity debuff if we don’t drop the water level.”
Sister Teresa of the Pure Cistern arrived at the foot of the ridge, riding in a high-wheeled supply cart loaded with five barrels of burning lime powder and three iron carboys of strong vinegar.
Her linen wimple was pinned tight against the wind.
“I’ve already smelled the monster from the river docks,” Teresa said. She stepped down from the cart with her brass slurry nozzle gripped in her hand.
“The water festers because it lacks the holy discipline of motion. Give me twenty barrels of lime, Lord Giles. I’ll scour the green demon until the basin is white as salt.”
“Burning lime powder won’t help fifty acres of deep water, Teresa,” Giles said.
“The volume is too great. You would stop the acidity for an hour, eat our entire lime stockpile, and end up with fifty acres of boiling skin-burning broth that kills every fish downstream.”
“Then what’s the remedy?” Teresa demanded, her knuckles tightening on the brass pipe.
“The remedy is shifted weight,” Giles said.
Captain Kenneth Drake marched up the line, with six spearmen carrying bundles of dry pine torches. He looked down at the pale green slime bubbling along the inner edge of the dyke.
“We can’t post sentries here,” Kenneth said bluntly. “Two men from the third picket felt dizzy after twenty minutes on the ridge. One of them coughed blood into his scarf.”
“Pull the sentries back two hundred paces,” Giles ordered. “Station them on the upwind shoulder. We remove the water that feeds the mold.”
Duncan Stone-Splitter let out a dry, rattling laugh. “And how do you propose to do that, Lord Baron? We can’t dig through twenty feet of hard speckled rock, and water doesn’t climb hills.”
Giles adjusted his glasses. He looked from the stale surface of the basin down to the dry drainage trench on the northern side of the ridge.
The height difference was significant.
The water surface in the sunken basin was twenty feet above the bed of the newly cut southern canal. Between the two bodies of water stood the granite ridge, acting as a twenty-two-foot barrier.
“Water doesn’t climb hills under gravity alone,” Giles said. “But water has mass, holding power, and weight. And the air above our heads has pressure.”
Duncan stared at him. “Air has weight?”
“Fourteen point seven pounds of pressure at sea level,” Giles said.
“A nonstop column of air pressing down on every square inch of that basin, just as it presses on the back of your hand. If we create a partial empty pocket inside a sealed pipe, the weight of the sky will shove that water straight up over the ridge.”
Toby Karr tilted his head, his eyes widening. “You mean... The air will push it over the top?”
“Exactly,” Giles said. “A drain tube loop. Long as the discharge outlet on the canal side is lower than the water level in the basin. Then, gravity pulls the dropping water column down the long leg.
That downward pull creates a low-pressure zone at the crown, and air pressure on the basin forces fresh water up the short leg to fill the void. Nonstop flow. Zero fuel. Zero draft animals.”
Duncan scratched his thick beard, his brow furrowed in utter disbelief.
“Water walking up a twenty-foot mountain because the sky is heavy. If any other man said that, I’d have him locked in the granary cellar with the mad weavers.”
“The mathematics are fully indifferent to your credulity, Duncan,” Giles said calmly.
* * *
The sun began to dip behind the western crags. It cast long, sharp shadows across the Black Fens.
Down in the basin, the green scum was visibly thickening.
Bubbles the size of dinner plates swelled on the dark water, bursting with dull, wet pops that released puffs of pale yellowish vapour. Where the gas drifted against the dry reeds, the stalks blackened and wilted within seconds.
“Look there,” Torvald whispered, pointing his copper wand toward the center of the pool.
Far out on the stale water, three yards from the reeds, a dark shape broke the surface. It wasn’t a fish.
It was an arched tangle of pale, hard-shelled ribs bound together by pulsating grey mycelium. As the air struck it, the rib-cage shuddered, and a low, whistling wheeze drifted across the marsh.
“The brood-spores are waking,” Torvald said, drawing his bone hunting knife. “They smell the open sky.”
“They smell methane,” Giles said, not bothering to look up from his sketchpad. “Toby, run to the south warehouse.
Tell Borin we need every length of eight-inch copper tubing brought up by ox cart. Every elbow, every sleeve, and forty pounds of lead-tin solder.”
Toby nodded eagerly. “On my way, Lord Giles!”
“And Kenneth,” Giles called out.
Kenneth Drake paused, turning back. “My lord?”
“Tell Sister Teresa to set up three burning lime powder spray stations along the levee crest,” Giles said.
“If the wind shifts south, keep the mist blowing toward the basin to knock down the airborne spores. And have Caleb build a two-metal tube wooden hand pump with greased leather flap valves.”
Kenneth looked down at the dark, pulsating shape in the water, then back at Giles’s blueprint.
“You’re going to pull that poison right over our heads,” Kenneth said softly.
“Through a sealed copper channel,” Giles corrected. “It won’t touch the air until it hits the lower scour trench.
When the basin dries, those spore-sacs will be sitting on dry gravel under open sunlight. Fungi hate direct bright purple exposure and dry air. Nature will do ninety percent of the demolition for us.”
Torvald lowered his wands, his amber eyes fixed on Giles with an expression that bordered on awe.
“The Master doesn’t strike the mountain,” Torvald murmured to Kenneth. “He commands the sky to drink the swamp.”
“Don’t encourage him, Chieftain,” Kenneth said under his breath. “He’ll have us trying to harness the clouds next.”