An army of five hundred men needed solid ground beneath its boots. Water, by its very nature, refused to provide it.
At dawn, the southern plain outside Grey Crag looked like an open-pit quarry. One hundred and twenty men, organized into three timed together shifts, swung pickaxes and shovels beneath a cold, steel-gray sky.
The outer edge moat was taking shape.
It encircled the entire settlement. A ditch twenty feet wide and fifteen feet deep, carving an arc of eight hundred yards from the river water chute on the west to the drainage ravine on the east.
Giles Croft stood on the rim of the digging with his spirit level and drafting clipboard.
Beside him, Toby Karr ran along the trench line with his chalk-reel, checking the depth against marked spruce pegs.
“Trench depth eleven feet at Station Four, Lord Giles.” Toby called up from the ditch, his face smudged with dark peat. “Master Duncan’s crew is hacking through the dark rock shelf below!”
“Maintain the forty-five-degree counterscarp angle,” Giles instructed. “The inner scarp must be dead upright. Line it with the four-inch volcanic cement concrete slabs as fast as Duncan splits the rock.”
Master Duncan Stone-Splitter stepped out of the trench, wiping stone dust from his eyes with the back of his forearm. Behind him, two draft oxen were hauling a flat wooden sledge laden with smooth gray concrete facing slabs.
“We have set two hundred slabs along the north curve, my lord,” Duncan reported, his voice raspy with dust. “Bonded with high-pressure lime mortar and pinned into the shale with iron spikes. If a man falls into this ditch, he will find no handhold. The concrete is slick as wet ice.”
“That’s the design intent,” Giles replied. “A smooth upright scarp prevents scaling ladders from biting and eliminates human climbing pathfinding.”
Lady Millicent walked the upper lip of the stone retaining wall, holding a brass line-weight-bob.
“The high-pressure concrete lining burned up forty barrels of burning lime powder,” Millicent noted, dipping her iron pen. “And twenty-four tons of washed dark rock aggregate. But our ditch digging yielded eighty cords of black peat. It the hospital and the kitchen hearths are already drying for winter fuel. A town defense work that pays an immediate heat dividend.”
“Digging byproduct utilization is deepest to resource smooth speed,” Giles agreed.
At the western terminus of the moat. There, the ditch met the main river water chute, Master Caleb Thorne-Wood and Master Borin Bronze-Lung were assembling the main water control gearwork.
It was the Great Sluice Gate.
The gate itself was a massive slab of seasoned white oak, eight inches thick, twelve feet wide, and ten feet high. It was bound in crisscrossing bands of forged iron. It weighed just over three tons.
The timber gate slid inside two upright iron guide channels bolted into the bedrock with two-inch anchor studs.
Kenneth Drake leaned on his ten-foot iron pacing rod, staring up at the huge gate with furrowed brows.
“Three tons of seasoned oak and iron,” Kenneth muttered. “And once the river backs up against it, the water head will exert five tons of deep water pressure against the timber face. It would take four yoke of oxen to lift that gate against the current.”
“Oxen are slow, need feed, and panic under fire arrows,” Giles said. He walked up to the timber framing. “We’ll not use oxen. We’ll use a twenty-to-one rack-and-pinion clockwork hoist.”
Giles pointed to the gear assembly mounted above the stone intake portal.
A massive wrought-iron rack, five feet long with deep-cut square teeth, was bolted to the center of the oak gate. Meshing with the rack was an eight-inch iron pinion gear, driven through an intermediate reduction gear by a two-handled cast-iron crank.
Suspended from two heavy chains running over grooved iron pulleys hung two heavy wooden boxes filled with fifteen hundred pounds of iron punchings.
“Counterbalanced clockwork advantage,” Giles explained to Kenneth. “The iron balance weights offset ninety percent of the gate’s dead weight. The leftover pushback is the sliding friction of the greased brass seals. The twenty-to-one gear reduction reduces worker effort to less than thirty pounds of handle force.”
Borin Bronze-Lung grinned through his copper beard, adjusting his fire gauge around his neck.
“Turned the teeth myself on the forge lathe,” Borin said. He tapped the iron gear with his wrench. “Smooth as pig lard. Go on, Kenneth. Give her a turn.”
Kenneth stepped up to the iron crank. He gripped the polished wooden handle with one hand, braced his feet, and pushed.
The crank turned with an easy, rhythmic clatter.
CHOCK-CHOCK.
High above the intake, the three-ton oak water gate lifted three inches from its granite doorstep without a shudder. The iron balance weights glided smoothly downward through their wooden guide chutes.
Kenneth blinked, staring at his own hand in sheer disbelief.
“One hand,” Kenneth whispered. “Three tons of iron and wood, and a child could lift it with one arm.”
“That’s what clockwork advantage does, Kenneth,” Giles said. “Force multiplied by distance. Lower the gate and seat the seal. We don’t flood the moat until the digging crews clear the channel.”
* * *
By the following afternoon, the ditch was finished.
Eight hundred linear yards of trench lay open around Grey Crag. The inner wall was lined with smooth, upright concrete slabs. It formed an unbroken gray cliff edge fifteen feet high. The bottom of the trench was paved with coarse dark rock rubble to prevent scour.
Toby Karr and the survey crew walked the entire outer rim, picking up shovels, survey pins, and wheelbarrows.
“Moat bed is swept and clear, Lord Giles!” Toby called from the gatehouse low roof wall.
Giles stood on the water gate platform beside Caleb and Kenneth. Below them, on the raised stone road, forty armed guards stood ready with bows and spears.
Giles checked his pocket watch.
“Open the water gate,” Giles commanded.
Caleb stepped up to the iron crank. He gripped the handles and spun the gear train.
The heavy oak gate rose into the timber frame.
An ear-splitting roar erupted from the river water chute.
High-pressure mountain water, surging under six feet of head pressure, burst through the intake portal in a foaming, roaring wall of white foam.
The torrent crashed into the empty moat bed with the force of a battering ram, throwing spray thirty feet into the air.
The brown water rushed along the concrete-lined channel. It hissed as it swallowed the dark rock rubble, surging around the curved northern castle wall in an unbroken, foaming wave.
Settlers crowded along the inner wooden wall narrow high walkways, cheering and pointing down at the rising water.
“Three feet,” Toby called from the depth marker. “Six feet. Ten feet. Twelve feet.”
Within forty minutes, the moat was full.
Two million four hundred thousand gallons of deep mountain water formed an impassable, glistening moat twenty feet wide and twelve and a half feet deep, encircling the entire settlement.
The water lapped against the smooth concrete scarp, swirling with a steady, quiet current that drained harmlessly through an overflow weir back into the river below.
Grey Crag was no longer an open frontier camp.
It was an island of stone, ringed by deep water and sheer concrete cliffs, accessible only by the narrow, defended raised stone road of the barrel arch bridge.
Duncan Stone-Splitter knelt on the concrete coping, watching the water swirl against the wall.
“Not a drop seeping through,” Duncan said, rubbing his hands together in triumph. “The high-pressure plaster holds every gallon. It’s an island! The town is a castle in the middle of a lake!”
Sister Teresa raised her brass slurry lance toward the sky, her eyes shining with holy joy.
“The water of the mountain has become our shield,” Teresa announcedto the weeping settlers. “The Lord Master builder has poured a river around our beds. The wicked shall find no footing.”
“It’s a twelve-foot high-pressure moat,” Giles corrected, noting the final water level on his clipboard. “It reduces ground assault vectors to a single choke point along the main raised stone road.”
Giles walked to the gatehouse stronghold and raised his telescope toward the southern pine woods.
The sun was sinking behind the western crags. It cast long crimson shadows across the snow-dusted scrub.
At the edge of the tree line, three hundred yards away, the pine branches parted.
Five mounted scouts of the Broken Horn burst from the forest on heavy mountain ponies. They were clad in greasy boiled leather, armed with short lances, riding fast to reconnoiter the approaches for Bronn’s siege train.
They charged across the frozen peat, intending to gallop right up to the timber wooden wall to test the gate.
Then they saw the water.
The lead rider hauled wildly on his reins. His pony skidded on its haunches, kicking up frozen mud and gravel, stopping barely three feet from the edge of the moat.
The other four riders slammed into each other in chaotic panic, their horses rearing and whinnying in terror.
The outlaws stared across the water with eyes wide as dinner plates.
Where their scouts had reported an open dirt ditch and a low wooden fence, there now lay a twenty-foot-wide moat of churning mountain water. They were backed by a fifteen-foot upright wall of seamless gray stone.
High above them on the gatehouse stronghold, the twin springalds sat silent in their stone embrasures. Their six-foot steel-tipped bolts shone in the twilight.
“What’s that?” one of the riders screamed, his voice cracking with terror. “Where did the lake come from?”
“It was dirt yesterday,” another outlaw yelled, fighting his panicked mount. “The Lord Master builder called the river out of the ground.”
“Ride back,” the lead scout shrieked, wheeling his horse around. “Tell Warlord Bronn. The town is an island. There’s no road.”
The five riders spurred their horses, fleeing into the southern pines in blind, disorganized terror.
Up on the stronghold, Kenneth Drake watched them go, his hands resting lightly on the low roof wall. A slow, cold smile spread across his scarred face.
“They didn’t like the bath, my lord,” Kenneth said.
“Their scouting was predicated on outdated cartographic data,” Giles replied, closing his sighting scope case. “Now they must recompute their assault vectors.”
He turned toward the gatehouse inside.
“The moat will stop their siege towers,” Giles said. “Now we must prepare the outer gatehouse for their battering ram. Master Duncan, Caleb. Bring up the murder-hole molds.”