Dawn was just breaking.
Xu Qinghuan sat upright before the desk, a vermilion brush suspended in her hand.
Stacked on the desk were the cotton yarn ledgers sent from Jiangning, while on the other side lay the Zhenbei Army's provision consumption registers for the past few days.
Her gaze shifted between the two booklets, her expression slightly solemn.
The Helian forces besieged the city without attacking, solely cutting off the water sources and pastures. The daily consumption of the thirty thousand troops and their warhorses in the city was enormous.
If they could not break the harassment of the roaming cavalry outside the city, this war would drag them into ruin sooner or later.
In the courtyard, a bare-chested Xu Zhan was wielding his horizontal sword, making it dance up and down.
The blade cleaved through the morning mist, letting out sharp, piercing sounds.
His swordplay was bold and sweeping, each strike carrying the momentum of a thunderbolt, yet it could hardly conceal the anxiety between his brows.
Yesterday, the night scouts went out of the city to investigate and were nearly ambushed. This pent-up frustration knotted in his chest, hard to relieve.
Suddenly, a clap of thunder erupted from the flat ground!
A deafening roar suddenly exploded from the backyard. The sound wave felt tangible, crashing against the window lattices and shattering the Korean paper pasted on the windows inch by inch.
The Duan inkstone on the desk jolted upward, splashing ink and staining half a page of the ledger.
Xu Zhan spun around, holding his horizontal sword across his chest. His eyes widened as he stared toward the backyard.
The blast wave swept up crushed stones and yellow earth, hurtling over the courtyard wall and raining down heavily.
The row of weapon racks in the corner of the courtyard was uprooted, sending spears and halberds clattering all over the ground.
"Enemy attack?" Xu Zhan shouted sharply, charging forward with his sword.
Xu Qinghuan threw down her vermilion brush, threw on her outer robe, and quickly followed.
Li Sheng from the front courtyard rushed over with over a dozen guards upon hearing the noise. The crowd drew their swords, tightly surrounding the moon gate of the backyard.
"Do not panic! Guard the outer courtyard. Without my orders, no one is allowed to enter!" Xu Qinghuan sternly ordered Li Sheng and the others back, stepping into the backyard alone with Xu Zhan.
What met their eyes was a courtyard in utter devastation.
A deep pit, three feet square, had been blasted into the originally flat blue-brick ground. The surrounding soil was scorched black, and a pungent smell of saltpeter lingered in the air.
Half of a charred wooden stake was stuck diagonally at the edge of the pit, still emitting wisps of blue smoke.
Before the smoke and dust settled, a figure stood at the edge of the pit.
Jenny Huang was covered in black soot, half of her left eyebrow burned off, her hair bun messy, and a few stray strands of hair plastered to her sweaty forehead.
Not only did she show no panic, but she was holding a perfectly round black iron lump in both hands. Her eyes shone brightly as she shouted, "It's a success! Eldest Miss, it's a success!"
Xu Zhan sheathed his sword and strode forward. His gaze fell upon the black iron lump, revealing a look of doubt. "What is this thing? It made such a commotion, it nearly tore this mansion apart."
Jenny Huang carefully placed the iron lump on the stone table. The object was pitch-black all over, shaped like a melon, with a rough surface covered in fine, dense seams.
"This thing is called the Iron Watermelon." Jenny Huang pointed to a protruding mechanism at the top, her tone elated. "It doesn't need a fire starter to ignite!"
"You just need to bury it in the sand and soil, covering the top with withered grass for camouflage. Once a warhorse's iron hoof steps on this pressure plate, the flint inside will shift and rub together, sparking into the powder chamber, and it will explode immediately."
To prove her words, Jenny Huang found a piece of jujube wood as thick as a wrist, pressed it against the edge of the pressure plate, and pushed down hard.
With a crisp click, the mechanism engaged.
"It is filled with iron caltrops and broken porcelain shards. When the gunpowder explodes, the iron fragments will shoot out in all directions. Let alone a horse's leg, even a heavily armored Helian elite soldier would have half his body blown off."
Jenny Huang clapped the black soot off her hands, her expression full of pride.
Upon hearing this, Xu Zhan's eyes burst with intense light. He clapped his hands and laughed heartily. "What a fine object! The Helian barbarians rely on their fast horses to harass our army's water sources and pastures every day."
"If we bury this thing on their inevitable routes like Laoya Spring, our night scouts will be like tigers with added wings when they leave the city. However many they send, that's how many will die!"
With that said, Xu Zhan turned and was about to head out. "I will go to the Commander-in-Chief's office right now to report this to Marshal Tie, and have the Armory Bureau work day and night to make a thousand or eight hundred of them. We will definitely make sure those barbarians never return!"
"Halt."
Xu Qinghuan took a step forward, her tone slightly deep, blocking the courtyard gate.
Xu Zhan looked back, showing confusion. "Little sister, military opportunities cannot be delayed. The sooner we make this thing, the fewer brothers will die outside the city."
Xu Qinghuan walked to the stone table, tapping the iron shell with her fingertips, producing a crisp sound. She raised her eyes to look directly at Xu Zhan, analyzing the situation clearly:
"Second Brother, wait. If you report this thing, Marshal Tie will naturally be pleased, but what about He Minghu? What about those officials in the Ministry of War in the capital?"
Xu Zhan froze, stopping in his tracks.
"Once the blueprints are handed over, the Ministry of War will definitely demand them in the name of promoting it to the entire army." Xu Qinghuan's voice was cold and hard, every word like a knife. "When it gets into their hands, fine iron will be replaced with inferior iron, and gunpowder will be mixed with miscellaneous dirt."
"Under layers of exploitation, by the time they are sent to the front lines, nine out of ten will be duds."
Xu Qinghuan's eyes flashed like lightning. "Even worse, if there is a mole seeking huge profits, they might sell the blueprints to the Helians at a high price."
"One day, this Iron Watermelon will be blowing off the legs of the soldiers and commoners under our command! How can such a weapon of mass destruction be easily revealed to others?"
Xu Zhan fell silent.
Having served at the border for a long time, he naturally knew how rampant the corruption of military equipment was.
The spears issued by the Ministry of War in the past had shafts made of rotten wood to make up the numbers, breaking at the slightest bend.
If corners were cut on such firearms as well, the consequences would be unimaginable.
"Then in your opinion, what should we do?" Xu Zhan asked.
Xu Qinghuan looked at the two of them and set the rules with absolute certainty: "This item must never be handed over to the Armory Bureau for mass production. It must be broken down into parts, and the core techniques can only remain in our own hands."
She turned to Jenny Huang and began deploying tasks: "The outer iron shell will be handed over to five blacksmith shops in the city to forge separately. Only half of it will be drawn on the blueprints, and we will publicly claim they are casting water canteens."
"The purification and proportioning of the gunpowder will be mixed by me personally in the secret room. I will absolutely not pass it to anyone else. As for this most crucial flint pressure plate fuse..."
Jenny Huang patted her chest, taking over the conversation. "The fuse will be hand-crafted by me alone. This work is delicate; a hair's breadth of error will cause a misfire. Except for me, no one else should even think about touching it."
Xu Zhan watched the two women divide up the production of this vital military weapon in just a few words. He felt somewhat relieved, but still had doubts. "If someone picks up an unexploded unit on the battlefield, takes it back, and forcefully dismantles it, wouldn't they still be able to see through its secrets?"
Hearing this, Jenny Huang broke into a smile, revealing her snow-white teeth.
She leaned closer to the stone table and pointed to an extremely fine gap beneath the mechanism. "Second Young Master, rest assured. I have kept a trick up my sleeve... Inside this fuse, I added a set of interlocking clasps called the Yama's Lock."
Jenny Huang used her fingernail to pick up a copper wire as thin as a hair. "A normal trigger requires pressure applied from top to bottom."
"If someone obtains the actual object and attempts to pry open the iron shell from the side to investigate the mysteries inside, as long as this copper wire shifts by half an inch, it will pull the inner spring..."
"What will happen?" Xu Zhan pressed.
"The flint will strike directly." Jenny Huang's tone was chilling. "The thieves won't even be able to touch the edges of the blueprints before they and the object are blown to smithereens."
The entire courtyard fell dead silent.
The wind temporarily ceased.
Xu Zhan looked at the inconspicuous black iron ball on the stone table, only feeling a chill rush from the soles of his feet straight to his forehead.
If others wanted it, they couldn't take it; if they wanted to steal it, they wouldn't even dare.
"What a ruthless method," Xu Zhan sighed deeply, though his eyes were filled with admiration. "With such defenses in place, I can finally rest easy! Little sister, how many can you produce in the first batch? Let me take the Night Scouts out of the city and give those barbarians a grand gift!"
Xu Qinghuan calculated for a moment before replying, "Raw materials are limited, and we must keep our work hidden from prying eyes. Within three days, we can produce at most twenty of them. Second Brother, you must be extremely cautious. The locations to bury them must be chosen meticulously; we cannot afford to waste a single one."
Xu Zhan walked into the courtyard, picked up a branch, and sketched a map of the terrain outside the city on the ground.
"The Helian cavalry are divided into several squads, each a hundred strong. They harass us during the day and retreat to make camp thirty miles away at night." Xu Zhan tapped the branch heavily against the dirt. "I will lead our men to lie in ambush ahead of time and bury these twenty 'iron watermelons' in a wild goose wing formation beneath the designated sand dunes."
He looked up, resting one hand on the hilt of his saber. "Once the lead horse steps on one, their formation will inevitably fall into chaos. The Night Scouts will charge in amidst the confusion, and we are bound to score a great victory."
Xu Qinghuan nodded slightly, warning him, "Remember, strike once and retreat immediately. Do not linger in battle."
"This battle is solely to establish our dominance, to let the Helian people know that the lands outside Zhenbei City are not their personal racecourse where they can come and go as they please."
"Understood." Xu Zhan tossed the branch aside and strode outward. "I am going to gather the men. We make our first move tonight."
