A deceptive military defense relied not on hiding an obstacle, but on making a lethal hazard look like a safe avenue of approach.
If the attacking army saw open water, they would halt and deploy pontoon bridges.
If they saw solid white ice, they would charge with the blind confidence of heavy infantry expecting an open highway.
Along the northern castle walls of Grey Crag, four hundred yards of dressed granite castle walls looked out across the snow-swept plateau.
Three-quarters of a mile away, the five hundred brigands of the Broken Horn were deploying into assault echelons with practiced, brutal discipline.
Their horned banners of black boiled wool fluttered in the freezing wind.
Armored oxen snorted white steam as they maneuvered the two massive thirty-five-foot siege towers into position, their heavy ash axles groaning under tons of timber and green hide.
Up on the castle walls, Giles Croft adjusted the brass regulating valves connecting the upper aqueduct water chute to the underground heating under-road drains.
Beside him, Master Borin Bronze-Lung held a brass thermocouple probe connected to a sensitive galvanometer.
“Heat spreading across sector north,” Giles commanded quietly. “Check the boundary layer heat at Pier Nine.”
Borin read the bending of the fine copper needle against the silver scale.
“Thirty-eight degrees Fahrenheit at the nozzle discharge,” Borin reported, his thick fingers adjusting the knurled wire end-post. “The warm water is hugging the stone scarp face just like you predicted, lad. The current keeps it from scattering outward.”
Giles pulled his wooden ruler from his pocket. He measured the width of the thaw channel through his sight sighting scope.
“Boundary layer fluid dynamics,” Giles explained to Toby Karr, who was steadying the tripod against the wind. “When warm fluid discharges along a smooth upright surface, thickness and wall shear create a stable boundary layer. The hot water doesn’t mix wildly with the outer frozen pool. It rises along the granite cut stone, creating a ten-foot ribbon of liquid water that melts the ice sheet from underneath.”
He tapped the bronze casing of the telescope.
“The outer ten feet of the moat remain four inches of solid, load-bearing ice. The inner ten feet—the sector directly beneath our murder holes and castle walls—is reduced to a brittle crust barely a half-inch thick.”
“Like the sugar crust on a burnt cream tart,” Toby observed, grinning faintly.
“A tart filled with fifteen feet of near-freezing mountain runoff,” Giles replied with dry care.
Yet a building challenge remained: steam.
Water at thirty-eight degrees meeting a surrounding air heat of twenty-two below zero produced visible plumes of white water drops.
If dense steam billowed from the foot of the wall, even the most reckless warlord would realize the ice was compromised.
Giles turned to Master Caleb Thorne-Wood and Sister Teresa, who stood on the lower firing berm with twelve settlement youths.
“Camouflage and heat padding,” Giles said. “We can’t stop the heat transfer, but we can mask the water drops.”
Down on the lower firing step, Captain Kenneth Drake was inspecting the equipment of thirty archers assigned to the northern low roof walls.
“Check your bowstrings,” Kenneth barked. He ran his fingers along a heavy recurve stave of mountain yew. “Raw flax snaps like dry twigs in twenty-below frost. Rub them with beeswax and sheep fat until the cords are warm and supple.”
Toby watched as the archers uncapped iron barrels containing four hundred heavy needle-point arrow arrows.
“Why the grease on the iron tips, Captain Kenneth?” Toby asked, peering into an arrow barrel.
“Sub-zero frost binds bare iron to leather quivers,” Kenneth explained, showing Toby an arrow point coated in a thin sheen of rendered lard. “When you draw an arrow in freezing wind, any frost on the tip catches on the fletchings of the shaft beside it. Half a second of pause is the difference between shooting the lead climber and taking an iron axe in your face.”
Giles nodded in agreement as he checked the stone embrasures.
“Lubrication and heat management prevent clockwork jamming,” Giles said. “In cold weather environments, material embrittlement accounts for sixty percent of weapon malfunctions. Ensure every archer keeps a second spare bowstring inside their woolen shirt against their ribs.”
Caleb carried a stack of wide, light wicker trays lined with coarse burlap sacking.
“Burlap snow-bridges,” Caleb said, demonstrating the technique. “We float the woven wicker trays right on top of the thin crust, anchored to the stone wall by light twine. Then we sift two inches of dry powder snow across the wicker.”
Teresa and her youths went to work with wooden grain scoops and wicker sieves.
They scooped fresh, dry drift snow from the courtyard drifts, gently dusting the white powder over the wicker screens.
The dry snow formed an insulating blanket that trapped the rising moisture. It condensed the steam beneath the fibers before it could escape into the biting winter air.
Within forty minutes, four hundred linear feet of the inner moat looked entirely uniform.
From two hundred yards away on the enemy lines, the frozen ditch appeared to be an unbroken, snow-dusted sheet of solid ice stretching all the way to the foot of the granite castle walls.
Toby climbed down from the last check pier, dusting snow from his woolen mittens with a broad smile.
“The bait is set, Lord Giles,” Toby whispered, glancing over his shoulder toward the enemy lines. “You couldn’t tell the difference if your life depended on it.”
Sister Teresa walked the narrow high walkway. Her hands were tucked into her heavy woolen sleeves as she peered down at the deceptive expanse.
Her dark eyes shone with solemn respect.
“The wicked shall walk upon a path of vanity,” Teresa said softly, reciting the verses of the Living Stone. “They shall say in their hearts, ‘Lo, the waters have turned to stone for our conquest.’ But beneath their proud tread, the earth shall open its maw and swallow the proud.”
Giles adjusted his woolen gloves, checking his pocket watch.
“It’s not an open maw, Teresa. It’s a calculated total collapse induced by nearby floating shifted weight and heat thinning. Please don’t attribute basic heat laws to demonic intervention.”
Teresa offered a gentle, knowing smile that made Giles wonder if she listened to a single word of his physics lectures.
“The engineer calculates the measure,” Teresa replied smoothly. “The Sovereign provides the frost and the flame. The result is righteous justice all the same.”
Giles sighed quietly, deciding that arguing theology during a coming soon siege assault was an inefficient waste of mental energy.
Lady Millicent arrived on the narrow high walkway. She carried a steaming copper kettle of hot broth and a tray of toasted oatcakes.
She handed a tin cup of broth to Giles and another to Kenneth Drake.
“One-use item rations distributed to all four castle wall crews,” Millicent reported, checking off a line in her tally-book. “Eighty pounds of dried beef, forty loaves of rye bread, and five barrels of small beer set in the gatehouse magazines. In the event of a prolonged assault, our defensive guard post can hold these castle walls for six weeks without drawing from civic emergency reserves.”
Kenneth took a swallow of the hot broth, his dark eyes fixed intently on the distant pine line.
“It won’t take six weeks, Lady Millicent,” Kenneth said. He wiped his mustache with the back of his gauntlet. “Warlord Bronn didn’t march five hundred men through a mountain blizzard to sit in the snow and starve. He carries no supply wagons. He has three days of grain at most. He must take Grey Crag today, or his army dissolves into freezing deserters.”
As if answering Kenneth’s prediction, a thunderous drumbeat rolled across the frozen valley.
Deep ox-hide war drums, beaten with heavy wooden mallets, began a slow, terrifying rhythm: THUD... THUD... THUD-THUD.
The ranks of the Broken Horn parted.
Warlord Bronn rode forward on his huge black destrier, its iron barding clattering in the freezing air.
The warlord was a mountain of a man, clad in plates of blackened steel trimmed with the jagged horn-plates of dire boars.
He rode to the center of the frozen plateau, barely four hundred yards from the town gatehouse, perfectly set just outside normal longbow range.
He drew his massive two-handed greatsword with a screech of polished steel.
The blackened blade ignited with a potion-made roar, tongues of greasy green and crimson flame licking along the cutting edges.
Bronn raised the burning sword high above his horned helmet. That turned his mount to face his five hundred howling warriors.
“Look upon their little stone playhouse!” Bronn bellowed, his voice carrying clearly across the snow-muffled silence. “A runaway clerk from the capital thought he could hide behind four walls and play at being a king!”
A roar of mocking laughter erupted from the bandit ranks.
Bronn turned his destrier back toward the gatehouse. He pointed the burning tip of his greatsword straight at Giles Croft on the castle wall.
“He built a wall! He built a water trough! But he can’t build a wall against the Broken Horn.
Bronn’s eyes burned with savage bloodlust beneath his steel visor.
“We take their grain! We take their warm hearths! We take their women for our winter beds! And when the gates are splintered, I will roast their Lord Master builder over his own forge fires until he begs to lick my boots.
The five hundred brigands threw their axes, spears, and iron shields into the air. It screamed a feral war chant that rattled the ice on the aqueduct arches.
Bronn wheeled his horse toward his vanguard.
“Fascine squads to the front,” Bronn commanded, his sword slashing downward. “Lay the timber bundles across the ice! Push the towers! CHARGE!”
A chorus of iron horns blew a piercing, shrieking fanfare.
From the front ranks of the Broken Horn, one hundred heavily armored shock troops stepped forward. He carried eight-foot bundles of water-soaked pine logs and woven brush. It was heavy fascines designed to bridge ditches and smooth the approach for their thirty-five-foot siege towers.
Kenneth Drake gripped the stone crenel, his knuckles whitening.
“Here they come, Lord Giles,” Kenneth said, his voice hard as iron. “Fascine squads leading the vanguard across the ice.”
Giles didn’t reach for a weapon. He drew his brass stop-watch from his pocket, snapping the winding stem with his thumb.
“Starting tactical test model,” Giles said calmly. “Ammunition allocations checked. Let them advance to the fifty-yard mark.”