The outer ditch was a freezing trench of shadow and hard-packed clay.
At twenty-six degrees below zero, the excavated soil was rigid as granite. It rang like cast iron under the studs of heavy boots.
Above the counterscarp lip, the fifty-mile-an-hour polar gale howled like a pack of starving ghosts. It whipped blinding sheets of white powder across the rim.
Down in the sheltered trench, Giles Croft crouched in the frozen dirt, his wool coat dusted white with blown snow.
Beside him, Captain Kenneth Drake, Borin, and Toby Karr worked in wild, hushed silence.
They had hauled the twelve fifty-pound wooden ward-pad cases down the access ramp on two deer-hide sleds, their breaths puffing white in the darkness.
On the ditch slope sat the twelve Directional Shrapnel Ward-Pads, their curved oak faces angled exactly forty-five degrees upward toward the crest of the counterscarp berm.
Each heavy wooden case was anchored to the frozen bedrock by two four-foot iron drive-stakes, sledgehammered into pre-drilled rock holes.
“Why the concave curve on the front plate, Lord Giles?” Borin asked, holding an iron drive-stake steady while Kenneth swung the leather-wrapped sledge.
“Wouldn’t a flat oak board be faster to build?”
“A flat plate produces an omnidirectional ball-shaped scattering pattern,” Giles answered, his flashlight beam lighting up the curved wood.
“Sixty percent of the striking force dissipates vertically into the air or backward into the trench bank.
By curving the oak backplate along a precise curved radius, we exploit the Munroe principle of focused blast shape.
Ninety percent of the expanding explosive gas focuses outward in a tight, sixty-degree level arc.
The iron pellets fly in a dense, scything sheet instead of a diffuse cloud.”
Giles adjusted his brass clinometer on the oak rim of station four.
“Check the declination angle on station four, Toby,” Giles instructed.
“If the box tilts upward by more than five degrees, sixty percent of your fragmentation fan discharges harmlessly into the sky.
If it tilts downward, the pellets bury themselves in the ditch clay thirty feet out.
The scattering fan must skim the snow crust at a height of twenty-four to thirty-six inches.”
Toby adjusted the oak leveling wedge beneath the rear support leg. He tapped it home with a wooden mallet.
“Angle is exactly six degrees upward, Lord Giles,” Toby whispered, shivering in the freezing trench.
“Anchored solid into the slate. The drive-stakes are wedged tight.”
Kenneth paused on the frozen berm, looking out across the white slope of the logging skidway.
“In the border wars at Ostrander’s Pass, the mountain clans used to dig shallow pit traps and scatter three-pronged iron caltrops,” Kenneth said. He wiped frost from his mustache.
“The caltrops crippled a few horses, but once the first rank went down, the following ranks trampled over their own dead and breached the ditch.
They had no staying power.”
“Caltrops rely on passive gravity contact,” Giles replied, sighting along the counterscarp lip with his transit.
“Passive obstacles suffer rapid saturation failure.
When the leading file falls, their bodies bridge the obstacle, neutralizing it for the second wave.
Our aimed ward-pads don’t wait for the enemy to step on them.
They project nine thousand six hundred active moving penetrators horizontally across the entire width of the approach hall.
It creates a dynamic moving firewall that shreds both the vanguard and the supporting files at the same time.”
Kenneth Drake crawled along the lip of the ditch, dragging a wooden spool of thin, hardened copper wire.
Every ten yards, he drove an eighteen-inch ash stake into the hard-packed berm crest, threading the wire through a small greased brass eyelet screwed into the wood.
“Why eighteen inches off the ground, my lord?” Kenneth asked, puffing white clouds of vapor into his beard.
“Wouldn’t an ankle wire catch them easier as they lope?”
“An ankle wire would be tripped prematurely by drifting snow crusted with wind-blown ice,” Giles explained.
“Also, eighteen inches corresponds exactly to the lower chest rib cage of an adult quadruped running at full extension.
A six-hundred-pound beast hits the wire at chest height. Then, the clockwork impulse is instant and definitive.
The wire can’t slip under the paws or be hopped over.”
Suddenly, a loud metal click rang out from station two.
Toby gasped, tumbling backward into the ditch snow.
The tripwire lever on the second ward-pad had snapped forward with a sharp click, its balance weight clattering against the oak casing.
Fortunately, the mana-deep ring primer pin had not yet been seated into the powder charge.
Kenneth froze, swearing softly under his breath.
“What tripped it? The wind?”
Giles crouched over the gearwork, inspecting the wire line with his pocket magnifying glass.
A slab of hard-crusted wind drift had sloughed off the berm lip, snagging the bare copper wire and dragging it sideways under fifteen pounds of lateral force.
“Ice crust adhesion,” Giles diagnosed calmly.
“In a gale, drifting snow forms wind-slabs that exert dynamic drag on exposed wire lines.
That was a fine-tuning flaw.
Toby, fetch the shears and the animal fat grease pots.”
Giles took the wire from Kenneth’s hand, demonstrating the fix.
“We replace the rigid copper anchor with a greased brass pulley and a two-pound counterweighted shear-pin.
Light surface snow will slide harmlessly over the greased wire without tripping the balance.
Only a sudden, rigid dynamic impact exceeding four point five pounds of direct force will shear the lead pin and release the firing hammer.”
Kenneth nodded grimly, pulling his shears from his belt.
“Makes sense. The snow pushes slow, but a charging beast strikes fast.”
Kenneth pulled a small brass fish-scale from his belt, hooking it to the modified release lever to test the pull pushback.
He pulled steadily until the lead pin snapped with a clean ping.
“Four point six pounds on the gauge,” Kenneth confirmed with a nod.
“Smooth and clean. Wind-drift won’t touch it.”
For twenty minutes, the three men worked their way down the three-hundred-yard line, retrofitting all twelve trigger assemblies with greased brass eyelets and counterweighted lead shear-pins.
They hidden the curved wooden faces of the ward-pads behind bundles of dry pine brush and trampled snow. That left only the concave iron face open toward the approach vector.
To any charging beast cresting the outer ridge, the kill-zone appeared as an ordinary, empty expanse of snowy slope leading down to the wooden wall.
* * *
Borin pulled a cold chisel from his leather pouch, scoring a deep circumferential notch around the top of each iron drive-stake before hammering it into the bedrock.
“Why the notch, Borin?” Toby asked, holding the lantern steady.
“When the fighting is done and the carcasses are hauled away,” Borin grunted, swinging the sledge with rhythmic care, “we slip a crowbar under that notch and pop the stakes right out of the slate.
No sense leaving good forged iron in the frozen dirt to rust.
We recycle every ounce for the spring plowshares.”
Giles smiled faintly in the darkness.
“Optimizing for post-raid material recovery is the hallmark of competent office design.
Every pound of iron salvaged reduces our next season extraction quota.”
Kenneth crawled back to station twelve at the eastern ditch angle. He tied off the final tripwire loop with steady, leather-gloved fingers.
He spat dark tobacco into the snow, looking back across the completed defensive array.
“Twelve ward-pads,” Kenneth murmured, a fierce, savage satisfaction in his gravelly voice.
“Linked sixty-degree cones.
Nine thousand six hundred chilled iron balls waiting behind thirty pounds of powder.
If they step across that berm crest, there won’t be enough left of their vanguard to fill a soup bowl.”
Toby Karr tied the safety lanyard to the master disarm peg, his hands shaking with tiredness and cold.
“Tension set on all twelve lines, Lord Giles!” Toby reported, his teeth chattering.
“The web is spun.”
Giles knelt beside station seven at the central dogleg bend of the ditch.
He took a small brass galvanometer from his instrument satchel, connecting the dual probe leads to the copper tripwire circuit.
The needle swung smoothly across the etched parchment dial, settling on the zero-pushback mark.
“Electric-shock circuit continuity checked,” Giles told Toby, who was watching over his shoulder with an oil lantern.
“No short circuits to ground.
The greased leather insulators around the mounting brackets are preventing mana-bleed into the frozen slate.
If an ice-wolf’s paw or flank brushes this copper strand, the electric-shock trigger pulse will initiate the primer coil within four split seconds.”
Kenneth Drake leaned against his pacing rod, watching the needle settle with quiet admiration.
“In the capital, the royal tunnel diggers would spend a month laying powder trains that got soaked by the first rainstorm,” Kenneth said.
“Here, we’ve got an iron web that triggers faster than a man can blink.
The beasts won’t even know what killed them.”
Giles pulled his field notebook from inside his greatcoat, recording the final grid map points for each station.
“Station one through six cover the sled skidway throat,” Giles noted.
“Station seven through twelve cover the eastern defilade approach.
The lateral overlap provides a ninety-eight point six percent fragmentation coverage across the entire frontage.
Now we withdraw behind the wooden wall and close the trench gate.”
Kenneth offered a hand, helping Toby scramble up the access ladder to the northern narrow high walkway.
Borin shouldered his sledgehammers, clambering up behind them.
Giles followed, his dark wood instrument case slung securely across his shoulder.
Toby blew warm breath into his mittens, looking back toward the northern timberline.
“The wolves won’t see the wire against the snow crust, Lord Giles,” Toby whispered.
“The copper tarnished to dark brown in the cold.
It looks like an old pine twig caught in the wind.”
“Visual camouflage is backup to sight line of sight,” Giles said.
“A charging hunting beast focuses on the dark shape of the wooden wall.
They don’t look at ground clutter until they’re inside the fragmentation cone.”
Behind them, the heavy spruce trench gate slammed shut. Its iron-shod drop-bars fell into place with a hollow thud.
The ditch was clear.
The trap was primed.
Up on the castle walls, eighty defenders stood in silence. It watched the swirling white blizzard curtain across the valley.
Out in the darkness, the howling of five hundred beasts was growing louder, closer. It shook the snow from the wooden wall logs with its raw, primal fury.
Kenneth tapped his ten-foot measuring rod against the narrow high walkway deck. He looked at Giles with a grim smile.
“All lines set, my lord.
Now we wait for them to ring the bell.”
Giles adjusted his wool scarf, pulling his watch from his pocket.
“They will contact the wire in about fourteen minutes.
Let us review the firing arcs on the giant crossbows.”