The pine oil torches on the city wall crackled wildly in the north wind.
The hoofbeats of the fifty riders from the Raid Battalion had long since completely melted into the thick night of the north.
On the wide horse path leading to the top of the city wall, however, came a rush of hurried and chaotic footsteps.
Su Mu, clutching the hem of his faded white robe, stumbled and threw himself up the horse path.
The hair bun on top of his head had long since skewed to the back of his head, a few stray hairs plastered to his face, sweating profusely.
He didn't even care that one of the cloth shoes on his feet had flown off.
"Lord Xu! Did the sky just fall!"
Su Mu rushed to the battlements, leaning more than half of his body out, his neck stretched out long.
"Or did the military workshop explode? Where's the noise!"
Li Sheng couldn't dodge in time and was bumped into a stagger by this bookworm. After steadying himself, he patted the dust off his sleeves.
"Lord Valley Master, the way you rushed here was even sharper than the warhorses of the Raid Battalion."
Hearing the voice, Xu Qinghuan turned her head, casually flipped open the lid of the mahogany long box, and handed it straight to Su Mu.
"It didn't fall."
"Just tested a new firearm, and conveniently let Xu Zhan pack three to take away."
The mahogany box was lined with soft cloth, the three round grooved pits were all empty, leaving only a small pinch of black-gray powder and a few rice-sized pieces of iron slag at the bottom.
Su Mu's bellyful of complaints got stuck in his throat.
He snatched the mahogany box, his fingers digging madly in the grooves, brought the layer of powder stained on his fingertips to the tip of his nose, and smelled it desperately twice.
"Concentrated sulfur, fierce fire saltpeter, this is top-grade smoldering charcoal powder..."
"Is this a blooming thunder sealed with an iron shell? How is the fuse made!"
He slapped the cold, hard city bricks next to him in anger, making his palms turn red.
"How could you not call me when such an epoch-making divine object is born!"
"What is the structure of the internal medicine chamber? What is the ratio?"
"How thick is the iron coat? How long does the primer burn before it explodes!"
This barrage of questions, with spit flying everywhere, made him so anxious that he spun in circles in a square space of ten feet.
Li Sheng rolled his eyes massively beside him.
"What's the use of calling? By the time you strolled over, the blast craters on the wasteland would have cooled down."
Su Mu jumped with anxiety, took a step forward, and tightly grabbed Li Sheng's collar.
"You saw it, right!"
"Tell me quickly! How did that thunder explode!"
Li Sheng was choked so hard by this crazy old man that his eyes rolled back, and his hands flailed wildly to pry open his finger bones.
"Let... let go first! I'll tell you!"
Only then did Su Mu willingly release his grip, stepping back half a pace, his gaze scraping Li Sheng's face like a knife.
Li Sheng rubbed his sore neck, exaggeratingly drawing a huge sphere in mid-air with both arms.
"Just an iron pockmark this big, the eldest miss lit the fuse and casually tossed it into a nest of dry grass."
"Boom——!"
Li Sheng gathered all his strength and stomped on the ground.
"My old man, that scene made the ground of the training field twitch!"
"Two dead horses weighing over a hundred catties were instantly torn into scattered minced meat, and caltrops flew everywhere!"
"A black pit half a zhang square was forcibly dug out of the flat ground, wide enough to fill two cows in!"
Li Sheng's lips flapped, getting more and more excited as he spoke.
"The second young master wished he could enshrine that fire thunder pot as an ancestral tablet and kowtow to it."
"Marshal Tie's eyes turned completely red, and he immediately grabbed the old craftsman of the Directorate of Armaments to ask if they could build a furnace overnight to make them."
The more Su Mu listened, the more anxious he became, rubbing his two well-knuckled hands back and forth in front of him.
"Cast iron shell... wrapped with shrapnel... delayed throwing..."
"Once cavalry are hit, they will definitely panic and trample!"
His face wrinkled into a bitter melon, looking at Xu Qinghuan.
"Lord Xu, you are guarding against me like a thief!"
Su Mu hugged that empty box, complaining tearfully.
"I stayed up for three whole nights without closing my eyes looking at the microscopic things under that microscope!"
"In the end, you didn't even send someone to inform me when you tested the firearms! No matter how dilapidated Sunset Valley is, I still need my face as the Valley Master!"
Li Sheng added a chilling remark from the side.
"Lord Valley Master, don't just care about your face, you still owe our workshop the material money for polishing the colored glaze lenses, this account hasn't been settled yet."
Su Mu was severely choked, his old face flushing red.
Xu Qinghuan neatly pulled the mahogany box from Su Mu's arms and 'snap' closed the lock.
"Li Sheng is right, clear accounts make good friends."
"Valley Master Su, taking advantage of the good moonlight, let's settle the accounts."
Xu Qinghuan raised her fair fingers, pointing down item by item.
"The blueprint of the microscope came from my hands."
"The first lesson on aquatic microorganisms was taught by me."
"The method of killing microorganisms with high temperature was personally verified by me."
"The concept of these three fire thunder pots tonight was also taken out by me."
Xu Qinghuan's gaze swept over.
"Since Sunset Valley entered North Suppressing City, having listened to so many top-secret classes of mine, Valley Master Su, have you paid half a copper coin in tuition?"
Only the howling sound of the night wind sweeping by remained on the city wall.
Li Sheng was very clever, somehow pulling out a palm abacus from behind his waist.
He flicked it cracklingly, forcibly displaying the aura of a debt-collecting accountant.
Su Mu was left speechless by the retort, freezing in place and blinking constantly.
He looked down at his old patched robe, hurriedly reaching deep into his sleeve pocket.
After tossing about for a long time, he first pulled out a small half piece of rock-hard mixed grain cold pancake.
He glanced at it in the moonlight, felt it was too shabby, and hurriedly stuffed it back under his sleeve.
Then he pulled out two waste drafts of lens grinding full of discarded ink blots.
Finally, gritting his teeth, he pulled out an inconspicuous small black porcelain bottle, with a yellowed and curled piece of rough paper stuck to the mouth, with the words 'use with caution' written on it.
Li Sheng walked over unceremoniously, stacking these tattered items piece by piece on the blue bricks of the city wall.
"Lord Valley Master, pick for yourself, which piece of scrap copper and rotten iron are you prepared to use to offset the tuition fee for the microscope?"
Su Mu's old face was hot enough to bake a pancake, and he snatched the small black porcelain bottle back to his sleeve.
"This medicine won't do, its nature is too fierce, if I really use it to pay off the debt, it's easy to send the creditor away overnight."
Xu Qinghuan was too lazy to play smart with him, directly pulling out a neatly folded piece of snow wave paper from her wide sleeve.
With a single flick of her hand, she slapped it directly on the battlements in front of Su Mu.
"Stop fooling me with rubbish. I don't lack medicine, I lack people."
Su Mu leaned in for a closer look and clearly saw the ink words on the paper.
"Sunset Valley is to immediately transfer twenty master craftsmen north, to enter the city within ten days."
"The team must bring all the old archives of mountains, rivers, and mineral veins, incomplete gunpowder formulas, blueprints of heavy iron smelting furnaces, and a catalog of rare medicinal seeds."
"All items are to be incorporated into the grand archives of North Suppressing City's manufacturing, and Sunset Valley is only to keep copies for record."
Su Mu gasped, his fingertips trembling.
This was clearly a bottom-fishing deed of sale! This was to suck the marrow out of the centuries-old blood and bones of Sunset Valley!
Xu Qinghuan unhurriedly tapped the paper, adding a poisoned sweet carrot.
"Bring the people over, and North Suppressing City will cover all the quotas for rations, coal, and refined iron, build a new workshop, and assign an independent large courtyard."
"After this, all the new gadgets created will be rewarded to Sunset Valley according to military merit."
"Valley Master Su, stop guarding that pile of broken bricks and shattered tiles wasting your years. North Suppressing City has a world that can let you toss out a big name."
Su Mu gritted his back molars, still making his final struggle.
"Twenty skilled veteran craftsmen! Sunset Valley doesn't even have that many breathing souls left who can handle heavy labor!"
"Those are the life-saving old archives left behind by our founder, how can we just hand them over to the public!"
"Besides, those fragmented gunpowder formulas were half-eaten by the rats in the valley long ago. Bringing them out would just make us a laughingstock for no reason..."
Xu Qinghuan did not bother bargaining with him at all. She simply tilted her head and gave a meaningful glance.
"Li Sheng, show him those slips."
Li Sheng grinned, pulled three red paper slips from his chest, lined them up in a row, and pressed them neatly next to the inventory list.
Su Mu glanced down, and his gaze was instantly glued to them, unable to tear itself away.
The first red slip read: "Second Major Lecture: Comprehensive Classification of Micro-organisms and Epidemic Prevention in the Casualty Camp."
The second red slip said: "Introduction to Ordnance: Manufacturing Method of Delayed Fuses and Shrapnel Lethality Simulation."
The third red slip: "Urgent Camp Requirement: Declassified Blueprints for Military Multi-layer Sand and Charcoal Water Filtration Tanks."
Su Mu stared at those lines of text and swallowed hard, a loud gulp echoing in his throat.
He slammed his hand against the green brick wall, instantly changing sides.
"Twenty people, I will gather them! Even if I have to smash my pots and sell my iron, I will get them for you, my lord!"
"I will bring all the old archives!"
"The old fragmented formulas, along with the paper scraps chewed by the rats, will be handed over together!"
Su Mu pointed at the list, his face flushed with anxiety, terrified that the other party would go back on their word if he was a second too late.
"But the fact that the formulas were ruined by rats is a natural disaster, it absolutely cannot be counted as Sunset Valley's lack of skill!"
A hint of a smile flashed through Xu Qinghuan's eyes as she casually handed over an ink-dipped brush.
"Sign."
Su Mu snatched the brush, his wrist trembling wildly as he swiftly signed his name at the bottom.
He did not even bother dipping his finger in red ink pad; he simply bit down on his thumb and pressed a heavy, bloody fingerprint onto the paper.
Throwing the brush to the ground, he turned and roared at the two panting apprentices who had just caught up to him.
"Change to fast horses and ride back to Sunset Valley overnight!"
"Count the heads, mobilize everyone to the absolute limit! Box up the entire library pavilion and the hidden archives, and load them onto the carts!"
"If you miss a single piece of paper with a word on it, I will personally break your damn legs!"
How could the two apprentices dare to delay? They scrambled and tumbled down the horse trail.
Having handled his rear guard, Su Mu turned back with a brazen face and held up a single finger.
"Lord Xu, I have emptied my entire foundation. From now on, in this Northern Garrison City, whenever you test anything that smokes, explodes, or flies in the sky..."
Su Mu pointed at the pitch-black wasteland, his voice resounding and firm.
"You must save a front-row seat for me to watch the spectacle!"
"If we truly encounter a life-threatening situation like a chamber explosion, at the very least, you have to let me see the mechanical structure clearly before I die!"
Li Sheng twitched his lips in disdain.
"Old Valley Master, what you are paying is not tuition; it is clearly your own toll fee to the afterlife."
Su Mu flicked his long sleeves, acting entirely justified, and said with a touch of arrogant pride.
"You ignorant brat, you know nothing! If I learn the truth of the Dao in the morning, I would consider it a profit even if I am buried in a dirt pit by the afternoon!"
