Ledgers Speak Only Facts

Screeech.

"Drag him out!"

The next morning, rough hands dragged me to the interrogation yard of the Uigeumbu, a place thick with the stench of blood. Under the glaring morning sun, glowing red-hot branding irons and terrifying torture implements were laid out in neat rows. And sitting in the seat of honor beyond them was my direct superior, the Right Assistant Minister of Taxation, wearing his crimson official robes and a sneering, malicious smile.

"You insolent wretch! Kim Jinseong, you stand accused of high treason for embezzling copper from the Type Casting Office and depleting the state treasury! Confess your crimes at once!" bellowed the high-ranking Uigeumbu official presiding over the court.

Park Inseok, the Right Assistant Minister of Taxation, quickly chimed in, pointing a finger at me.

"My Lord! This man has always been greedy and of loose morals! He has undoubtedly smuggled the copper to a Ming merchant group and hidden the profits. We must crush his legs on the torture chair immediately to wring a confession from him!"

What a pathetic, well-choreographed circus.

The guards approached with menacing scowls, preparing to wedge the thick wooden poles between my thighs to twist my legs. Just before they could begin, I slowly raised my head.

"Wait."

That single word made the guards freeze in their tracks. Seizing the moment of their hesitation, I held my head high and stared straight into the eyes of the Uigeumbu magistrate.

"Do you have any actual proof that I embezzled the copper? Or is this merely the Right Assistant Minister's groundless suspicion?"

"How dare you deny it to the end! Are you not the Hojo Jeongrang in charge of managing the Type Casting Office?"

"Yes, I am the officer in charge. Which is precisely why I know the truth better than anyone. Tens of thousands of catties of copper—a massive chunk of the state budget—have vanished into thin air. Why has the Right Assistant Minister not checked the most basic evidence of all: the ledgers?"

At my words, I saw a subtle twitch in Park Inseok's facial muscles. I didn't miss the opening and drove the wedge deeper.

"I will catch the real culprit with my own hands. Just bring me three things: the Ministry of Taxation's transaction ledgers, the Hanseong-bu carriage logs, and the Taepyeonggwan cargo registry."

"Madness! My Lord, he is merely spouting nonsense to delay his punishment! Strike him at once!" Park Inseok shrieked, his face turning pale.

But I saw it clearly. The Uigeumbu magistrate's eyes flickered with a hint of intrigue, drawn in by my absolute confidence and audacious proposal.

"Just half a day. Half a day is all I need."

Bound in ropes, I knelt on the cold dirt floor and smirked. "If I fail to trace the missing copper from those ledgers, you may take my head right here on this very spot."

The deep wrinkles on the magistrate's face creased further. The sheer audacity of a mere Junior 5th Rank official staking his life. Yet, in my eyes, there was no trace of a madman's frenzy or a doomed man's despair. There was only absolute certainty.

"...Very well."

"My Lord! How can you believe the words of this lunatic? We must torture him immediately!"

"Silence, Assistant Minister!" The magistrate's thunderous bark made Park Inseok flinch and shut his mouth. "The Hojo transaction ledgers, the Hanseong-bu carriage logs, and the trade records of the Ming envoys, you say? I shall have them delivered to your cell before dusk. However, if you fail to find the culprit by sunset, your head will be impaled on a pike at the marketplace."

"That is more than enough."

I gave a slight nod. Even as I was dragged away, I kept my eyes locked on Park Inseok. Though his face flushed red with feigned anger, a sneer of mockery lingered deep within his eyes.

Go ahead, laugh.

To them, reviewing tens of thousands of pages of Joseon's primitive, handwritten ledgers in a mere half-day was physically impossible. Let alone cross-referencing records from three entirely different government agencies to trace the flow of capital. Even the greatest mathematical genius in Joseon couldn't pull that off—at least, not in this era of single-entry bookkeeping.

Thud!

Not long after I was thrown back into my cell, the guards arrived carrying A-frame packs loaded with mountains of ledgers, dumping them onto the floor. Amidst the rising cloud of dust from the ancient, musty volumes, they tossed in an inkstone, a brush, and a few clean sheets of mulberry paper.

"You have until sunset."

I heard the guards whispering beyond the wooden bars. Instead of replying, I rolled up my sleeves.

"Now, let's see just how amateur Joseon's creative accounting really is."

I soaked my brush in thick black ink and drew lines on the clean paper. One long horizontal line, and one vertical line down the middle. The T-account ledger—the very heart of accounting and the crown jewel of capitalism.

Flipping rapidly through the Joseon ledgers filled with dizzying Hanja characters, I began translating the data into my most intuitive language—Arabic numerals—and writing them down.

1, 2, 3, 4, 5...

"W-what on earth is he doing on the cell floor?"

"Those aren't characters. It looks like some bizarre talisman... He must be possessed by a ghost."

The guards muttered in terror, but their voices faded into the background. When concentration reaches its peak, the rest of the world simply ceases to exist.

If physical goods vanished, they needed a way to transport them.

The Ministry of Taxation's ledger claimed the copper was safely in the warehouse. However, the Hanseong-bu carriage logs revealed that on the fifteenth of last month, thirty large carts in the Jongno area had been rented out simultaneously to a specific merchant group.

The stated purpose was "transporting firewood"? Who on earth moves thirty cartloads of firewood in the dead of summer?

I let out a dry chuckle at the sheer sloppiness of the lie. I cross-referenced the destination of those carts with the cargo registries of Taepyeonggwan, recorded by the interpreters of the Bureau of Interpreters.

We can't force open the private ledgers of the Ming envoys, but they couldn't completely erase the official declarations they made to our interpreters while trading on Joseon soil.

The merchant group of the wealthy Ming merchant, Wang Lao-da. According to the interpreters' records, the amount of silver they paid to purchase Joseon ginseng and silk was over three times their usual volume. They had cleverly disguised the illicit payment for tens of thousands of catties of copper as a massive purchase of ginseng.

Yet, naturally, the massive shipment of silver bullion that should have entered the Ministry of Taxation's treasury was nowhere to be found in the official ledgers. It had vanished mid-transit.

A debit omission of copper, a credit omission of silver bullion. Classic embezzlement.

So where did the silver go? My eyes locked onto a merchant inn in Unjong-ga, near Taepyeonggwan, where the carts had made their final stop. An establishment run by the brother-in-law of Park Inseok, the Right Assistant Minister of Taxation.

"Game over."

I set down my brush. The sun was beginning to dip below the horizon.

"Time is up! Drag him out!"

The heavy iron lock on the cell door was violently unchained. The Uigeumbu interrogation yard was bathed in the long, crimson shadows of the setting sun. The promised half-day had expired.

Bound in ropes, I was dragged out by the guards and forced to my knees in the center of the courtyard. The Uigeumbu magistrate sat with a grim expression, while Park Inseok stood beside him, a smug, victorious sneer plastered across his face.

"Well? Have you found the whereabouts of the missing copper?"

At the magistrate's solemn demand, I pulled a neatly folded sheet of mulberry paper from my robes and held it out. An officer carefully took it and presented it to the magistrate.

"W-what on earth is this bizarre scribble? There are lines drawn everywhere, and these incomprehensible symbols..."

The magistrate's brow furrowed deeply as he stared at the T-account ledger and the dense rows of Arabic numerals. I straightened my spine and spoke in the calm, measured tone I used to use when briefing high-profile cases back at the National Tax Service.

"Ledgers speak only facts, My Lord. On the fifteenth of last month, the Ministry of Taxation's records claimed the copper was safely in the warehouse. Yet, on that very same day, Hanseong-bu logs show thirty large carts were rented out to a merchant group in Jongno under the guise of 'transporting firewood.' Who on earth transports thirty cartloads of firewood in the sweltering heat of midsummer?"

As precise dates and figures poured from my mouth, Park Inseok's face stiffened.

"Those carts traveled down the back alley of the Type Casting Office and headed straight for Taepyeonggwan, where the Ming envoys reside. While we cannot inspect the private ledgers of the imperial envoys, the meticulous cargo registries kept by our own interpreters cannot lie."

I raised my chin, staring directly at Park Inseok as I delivered the final blow.

"According to those registries, the merchant group of the Ming merchant Wang Lao-da purchased Joseon ginseng and silk that day, paying an astronomical sum of silver bullion—more than three times their usual transaction volume. They cleverly disguised the payment for tens of thousands of catties of smuggled copper as the price of ginseng."

"Y-you insolent wretch! What kind of fantasy novel are you spinning here? How dare you make such wild accusations based on a few moving carts...!" Park Inseok shrieked, pointing a trembling finger at me.

I offered him a broad, mocking smile.

"And naturally, there is not a single line in our records showing that this massive amount of silver bullion ever ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠entered the state treasury. So, where did all that money go, Right Assistant Minister?"

"..."

"Pimat-gol in Unjong-ga. The underground warehouse of the Songsang Inn, operated by your brother-in-law. Send the Uigeumbu guards there right now, My Lord. You will find tens of thousands of taels of silver bullion, stamped with the seal of the Ming imperial court, sitting there pristine and untouched."

A heavy silence descended upon the interrogation yard. The color drained from Park Inseok's face, leaving him looking like a pale corpse. His trembling hands betrayed his guilt far better than any words could.

"At once... dispatch the investigators to Pimat-gol immediately!"

At the magistrate's urgent command, the guards mounted their horses and galloped away in a cloud of dust. About thirty minutes later, a breathless Uigeumbu investigator rushed back and threw himself onto the ground.

"M-My Lord! Jeongrang Kim was correct! We discovered dozens of heavy chests filled with silver bullion hidden beneath piles of straw in the basement of the Songsang Inn! None of them bore the official seal of the Ministry of Taxation—instead, they were stamped with the private mark of the Right Assistant Minister!"

Thud.

Park Inseok's legs gave out, and he collapsed onto the dirt.

"This... this cannot be... How could anyone find this in a single day from tens of thousands of chaotic records..." he muttered, completely dazed.

As the guards untied my ropes, I looked down at the pathetic figure sprawled on the ground and spat out a cold remark.

"Next time, Assistant Minister, I suggest you manage your dummy accounts—ah, I mean, your ledgers—a bit more carefully."

"Drag this treacherous thief away and throw him into the dungeons! Put him on the torture chair and extract every single one of his crimes!"

At the magistrate's furious roar, Park Inseok let out a beastly shriek as the guards dragged him away.

My very first tax audit against the Joseon ruling class. The result was a landslide victory.

It was late at night by the time I was cleared of all charges and stepped out of the Uigeumbu gates. Having spent an entire day on a literal life-or-death rollercoaster, every bone in my body was screaming in agony. It seemed Kim Jinseong's physical constitution was far weaker than my original body.

"Sigh... Let's just go home, take a hot bath, and sleep like the dead for three days."

Just as I was about to take a heavy step forward, a shadow silently glided out from the dark alleyway and blocked my path. It was a man clad in a deep navy robe, straight out of a historical drama. Hanging from his waist was an official identification plaque engraved with the royal crest, gleaming under the moonlight. An officer of the Royal Guard (Naegeumwi).

"Are you Hojo Jeongrang Kim Jinseong?"

"...I am. What is this about? My investigation was just concluded."

A sudden wave of foreboding washed down my spine. The Royal Guard scanned our surroundings before speaking in a low, heavy voice.

"His Majesty requests your presence. In secret."

Gyeongbokgung Palace was shrouded in the deepening twilight. My steps, as I followed the Royal Guard, felt as heavy as lead. Having rolled around on a cold prison floor and endured a brutal interrogation at the Uigeumbu, Kim Jinseong's frail body had long since passed its limits.

Sigh, I just want to wash up and sleep.

But I was in no position to complain. The place I was heading to was the very heart of Joseon—Sajeongjeon, the King's executive office.

"You may enter."

The heavy wooden doors creaked open, revealing the interior of the hall illuminated by the flickering glow of dozens of beeswax candles. A suffocating silence hung in the air, thick with the scent of aged paper and ink. The moment I crossed the threshold, I threw myself flat onto the floor and bowed deeply.

In my past life, I hadn't so much as blinked when facing the chairmen of the nation's top conglomerates. Yet, the sheer aura radiating from a true absolute monarch was on an entirely different level.

Carefully raising my head to steal a glance at the throne, I was utterly stunned.

...That man is King Sejong the Great?

The warm, grandfatherly figure from the ten-thousand-won bill was nowhere to be found. It was the year 1434, the sixteenth year of his reign. King Sejong was currently thirty-seven years old. This was not the frail, ailing monarch of his later years, but a ruler at the absolute zenith of his intellect, political cunning, and physical strength—a complete sovereign who utterly dominated his court.

True to the historical records of his heavy meat diet, his broad shoulders and robust frame beneath the scarlet royal robes were as imposing as any elite warrior of the Royal Guard.

Raising his head from a mountain of state reports, the thirty-seven-year-old King pierced me with eyes as sharp and intelligent as a tiger's. He was, in every sense, Joseon's ultimate budget-breaker and an extreme workaholic.

"Are you Hojo Jeongrang Kim Jinseong?"

"Y-yes, Your Majesty. I am Jeongrang Kim Jinseong."

Sejong rested his chin on his hand and stared down at me for what felt like an eternity. Just as cold sweat began to trickle down my spine from the oppressive silence, he tossed a bundle of papers onto his desk. It was the very double-entry ledger I had handed to the Uigeumbu magistrate earlier that day.

"I have reviewed countless records from the Ministry of Taxation, yet I have never seen a ledger as bizarre as this." Sejong's deep, resonant voice echoed through Sajeongjeon. "You drew straight lines horizontally and vertically, filling them with incomprehensible symbols. Yet, astonishingly, the fate of tens of thousands of catties of copper and the flow of silver bullion can be understood at a single glance. Did you devise this method of calculation yourself?"

I took a brief breath. Claiming I invented it would only invite trouble. Especially before this notoriously obsessive scholar-king, who would undoubtedly grill me on its underlying principles and philosophy. I bowed my head as low as possible and gave a smooth, calculated response.

"...No, Your Majesty. How could a mere low-ranking official like myself ever hope to devise such a miraculous method?"

"Oh? Then from whom did you learn it?"

"It is a secret art used by the wealthy merchants of the West, in a land far beyond the Middle Kingdom called Arabia."

"The West!"

In an instant, Sejong's eyes flared. This was no longer just the mild curiosity of a king looking at a clever subordinate who had caught a thief. It was the explosion of his trademark intellectual thirst upon encountering unknown knowledge, a new science, and a highly practical field of study. Leaning forward eagerly from his throne, Sejong pressed, "Merchants of the West beyond the Ming Empire, you say? Those blue-eyed foreigners who cross vast deserts and treacherous seas to amass astronomical wealth? Is this the calculation method they employ?"

"Indeed, Your Majesty. When those Western merchants conduct transactions worth thousands of gold pieces across tens of thousands of miles, they do not write long, winding paragraphs with a brush as we do in Joseon. Instead, they use those very symbols you see—Western numerals—to record incoming assets and outgoing expenses, ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠strictly dividing them into left and right columns."

"Dividing left and right..."

"Yes, Your Majesty. This is called double-entry bookkeeping. If a single digit on one side is altered, the other side will inevitably fail to balance."

"Double-entry... dividing left and right to make them interlock like the gears of a carriage? And through this, even the slightest discrepancy or embezzlement can be detected?"

"Precisely, Your Majesty. Numbers never lie. The Western method is a system that records nothing but the absolute truth."

Sejong stroked his beard, letting out a deep exclamation of awe. "Haha! Remarkable. Truly, what a wondrous logic! Even the Minister of Taxation slapped his forehead in admiration upon seeing your ledger, and now I see he had every reason to do so."

Sejong traced his fingers over my double-entry ledger as if it were a priceless treasure. To Joseon's greatest knowledge-enthusiast and pragmatist, a Western secret art that enabled flawless statistics and accounting must have felt like a refreshing rain in the middle of a devastating drought.

But the warm atmosphere was short-lived. The moment Sejong tore his eyes away from the ledger, his gaze sharpened to a razor's edge.

"Since your talent for handling numbers is extraordinary and you have mastered this rare Western science, I must entrust you with a task."

Flap! Flap! Sejong roughly tossed two thick scrolls from his desk, landing them right in front of me.

"One is a requisition request submitted by Hogun Jang Yeong-sil, stating he requires more funds to complete the striking clepsydra and the sundial. The other is a detailed invoice for military rations sent by Choi Yun-deok of Pyeongan Province and Kim Jong-seo of Hamgil Province for the pioneering of the Four Counties and Six Garrisons."

Holding my breath, I carefully unrolled the documents on the floor. The moment I scanned the densely packed text, I had to swallow a barrage of curses.

Are you insane? A massive R&D budget request on top of military rations for a northern campaign? The state treasury is practically empty, and you want to approve this?

Joseon's current financial state was on the brink of bankruptcy. Thanks to Sejong's endless stream of projects, casting the Gabinja metal type alone had consumed two hundred thousand copper coins, leaving the state granaries so barren that even the mice were starving. Yet, he wanted to squeeze out astronomical research funds and tens of thousands of bags of military rations on top of that?

"I shall give you fifteen days."

"...Pardon?"

"Use that miraculous bookkeeping of yours to scour every single ledger in the palace, and secure this budget within fifteen days."

My breath caught in my throat. This was the classic, ruthless pressure corporate chairmen used to squeeze their subsidiary CEOs. A silent threat from absolute power demanding results by any means necessary. If I were the original, timid Kim Jinseong, I would have been shaking like a leaf, begging for my life. But I am Kang Jinsung. If I'm going to die either way, I might as well place a massive bet.

I snapped the scrolls shut and slowly raised my head. My exhausted brain began to operate with icy precision.

"Your Majesty."

"Speak. Have you found a way to secure the budget?"

"No. You are bankrupt."

"...What?"

Sejong's thick eyebrows twitched. I heard the eunuchs and royal guards standing nearby gasp in sheer terror. Ignoring them completely, I delivered the cold, hard facts.

"With our current tax revenue, the state will default in two months. As for that northern campaign budget, it must be completely rejected."

A heavy silence fell over Sajeongjeon.

"Rejected? How dare a mere official like you pass judgment on a national enterprise."

"The conquest of Tsushima and the northern expansion are deficit-ridden ventures with zero return on investment. Have you calculated the logistics of the supply lines? For a single bag of rice dispatched from Hanyang to reach General Kim Jong-seo in Hamgil Province, the porters trekking through the rugged mountain passes consume more than two bags along the way! To deliver one bag, you must burn through three. It is like pouring water into a bottomless pit."

Sejong's eyes flashed with a murderous glare. The tension in the room was suffocating, as if a single word from him would have my head rolling on the floor.

"Are you... truly defying my command?" Sejong's heavy voice pressed down on me like a massive boulder.

The air in the hall grew incredibly heavy, but I did not avert my gaze. Instead, I let my lips curl upward and threw out a counter-proposal.

"Your Majesty's landmark tax reform, the Gongbeop. Has it not been stalled for years due to the fierce opposition of the conservative Gwanhak faction?"

"...And what of it?"

"There is no money in the treasury anyway. Squeezing the commoners any further is like trying to wring water from a dry sponge. If you absolutely must proceed with these demanding projects, then grant me absolute authority."

I let my true colors show—the ruthless nature that had earned me the nickname 'Grim Reaper of the business world' back at the National Tax Service.

"I will hunt down every single hidden estate that those corrupt, powerful clans have deliberately omitted from the registries to evade taxes. I will shake them down and secure the massive funds you require."

A declaration to legally plunder the wealth of the ruling aristocracy to fund the King's vision. The murderous glare in Sejong's eyes instantly transformed into a spark of profound intrigue and delight.

"If you grant me absolute authority, I will seize the hidden lands that those corrupt, powerful clans have deliberately omitted from the registries to evade taxes, and use those funds to secure your northern campaign budget."

The air in Sajeongjeon froze instantly. I saw the hands of the Royal Guards standing around me tighten on their hilts. A mere low-ranking official kneeling before the throne had just declared his intention to seize the ruling ministers by their throats. It was an audacity that warranted immediate execution.

Yet, Sejong's reaction from the throne was entirely different.

"..."

The thirty-seven-year-old monarch stared at me with a piercing gaze, then stroked his beard and muttered softly, "Hidden lands. I am well aware that the reason the Gwanhak faction has opposed my tax reforms for years is their fear of having their own concealed estates and wealth exposed."

Sejong leaned forward. "However, they are not easily dealt with. They are old foxes who slip through even the tightest nets of the Saheonbu. How do you propose to expose their hidden wealth?"

"If we fight them with swords or political justification, we will lose every single time."

"Then how?"

I began to brief him on the tax audit process I had mapped out in my head.

"No matter how deeply they conceal their lands or hide their slaves, the rice and silk produced from those estates must eventually flow into the market to be liquidated. By reverse-tracking the distribution of salt and textiles consumed in Hanyang and running a cross-verification using the Western method, we can pinpoint the exact locations of their dummy merchant groups and secret plantations."

As I finished, a heavy silence enveloped the hall. Sejong closed his eyes, seemingly running calculations in his mind. As Joseon's greatest genius, he was undoubtedly weighing my auditing method against the astronomical budget it could secure.

"...Puhahaha."

Before long, the corners of Sejong's lips curled into a wide grin. "To hold the ministers by their throats in such a manner! What an arrogant yet marvelous concept, truly fitting for one who has mastered a secret Western art!"

Sejong burst into hearty laughter and slapped his knee. To a budget-breaking monarch who desperately needed to spend endless funds to lay the foundations of his nation, my proposal must have sounded like the sweetest honey.

"Very well. I grant you absolute authority. Use that calculation method of yours to track down every single hidden asset of the Gwanhak faction and reclaim them for the state treasury."

"Your grace is immeasurable, Your Majesty." I bowed as politely as possible, subtly slipping in my core condition. "However, Your Majesty, I have one humble request."

"Speak."

"Conducting these tax audits... that is, tracking down the hidden wealth of the high ministers, is an incredibly dangerous and grueling task that requires me to risk my life. Therefore, I request a fair commission based on my performance."

"A commission?"

Sejong's eyes sparkled with amusement. An official daring to openly demand money in front of Joseon's greatest sage-king. It was a feat impossible for anyone without nerves of absolute steel.

"Yes. When I recover the hidden funds, I ask that you allow me to retain one-hundredth—one percent—of the total as an investigative expense and commission."

The Royal Guards gasped in sheer horror at my insane audacity to bargain over a royal decree. But Sejong did not anger. Instead, he let out a booming laugh and nodded. After all, this was money that would otherwise never enter the state treasury, wealth that could never be found. If he could secure ninety-nine percent of the budget by giving away a mere one percent commission, it was the greatest bargain he could ever ask for.

"Excellent! It is money I would have never laid eyes on anyway. I gladly grant your request!"

A clean, decisive approval. I cheered inwardly. A perfect, legal channel to amass immense wealth and build a personal slush fund had just opened. At the very least, I wouldn't have to worry about starving to death due to the ruinous state of Kim Jinseong's family in this era.

‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠

"However, your current rank is only a Junior 5th Rank Hojo Jeongrang. With such a low rank, your authority will be far too weak to investigate the Chief State Councillors and Ministers."

At Sejong's gesture, the Royal Secretary standing nearby brought forward a red royal decree.

"This morning, I dismissed and imprisoned the former Right Assistant Minister of Taxation, Park Inseok, for embezzling copper from the Type Casting Office. This leaves a vacant seat for a Senior 3rd Rank Dangsang-gwan."

A meteoric rise from a Junior 5th Rank to a Senior 3rd Rank Dangsang-gwan, earning the right to wear the red official robes and attend the core state council meetings. In a single day, I had seized the very position of the superior who had tried to oppress and execute me just yesterday.

"I shall repay Your Majesty's immense grace even if my bones are ground to dust!"

I accepted the royal decree with both hands and pressed my forehead to the floor with utmost sincerity.

The next morning, the headquarters of the Ministry of Taxation (Hojo Cheongsa) was in utter chaos.

"H-he is coming!"

"Heavens! It really is the red robe!"

Just yesterday, I was a miserable Junior 5th Rank official locked in a cell, awaiting execution. Yet, as I walked into work this morning, I was draped in the vibrant red robes of a Senior 3rd Rank Dangsang-gwan, complete with an ornate embroidered rank patch on my chest.

The officials of the Ministry of Taxation parted like the Red Sea, staring at me as if they were looking at a ghost. With my hands clasped behind my back, I strode confidently into the spacious office of the Right Assistant Minister of Taxation—the very room Park Inseok had occupied just yesterday.

"Alright, attention everyone."

The working officials and clerks gathered in the office swallowed hard, their eyes locked on me. I slammed the special auditing decree granted by Sejong onto the desk with a sharp clack.

"Starting today, we have a massive backlog of work to get through."

"Pardon? Assistant Minister, what do you mean by..."

"We're going on a field trip. To shake some people down."

I looked out the window and smiled. The leader of the faction opposing the Gongbeop most fiercely in the court was none other than the Senior 1st Rank Chief State Councillor, Lord Hwang Hui.

Though praised by future generations as a clean-handed, upright official, the Hwang Hui of this era was a cunning, slippery political titan who checked Sejong's authority and championed the interests of the landowning elite.

Taking down the final boss right off the bat is an amateur move. If I ruin the Chief State Councillor now, who will I have left to shake down later?

My goal was not to have Hwang Hui dismissed. It was to uncover his family's corruption—his fatal weakness—and use it as political leverage. To force him into submission, I had to dry up his financial lifeblood first.

"Listen up, everyone. Our target is the hidden estates of the Chief State Councillor's family scattered across Chungcheong Province."

The clerks' jaws dropped in sheer horror. Investigating the personal assets of the Chief State Councillor, the pinnacle of power in Joseon. A boss who was completely, utterly insane had just taken charge.

Yet, before the Dangsang-gwan rank patch on my chest and the royal decree issued by Sejong himself, no one dared to utter a single word of protest.

"Bring me all the logistics ledgers from Chungcheong Province over the past three years, along with the records of salt and textile shipments sent from Hanyang to Chungcheong."

To feed and clothe thousands of unregistered slaves on hidden estates meant to evade taxes, they absolutely required massive quantities of salt and fabric. By reverse-tracking these shipments, we could pinpoint the exact locations of their dummy merchant groups and secret plantations.

The clerks groaned as they hauled hundreds of dusty, handwritten ledgers, piling them like a mountain on the office floor. Soon, the Ministry of Taxation headquarters was filled with the scratching of brushes and the rhythmic clack-clack of sangaji—Joseon's traditional counting rods.

I paced back and forth with my hands behind my back, supervising their work.

Sigh, this is painfully slow.

Joseon's accounting was a primitive system of writing down transactions in long, narrative paragraphs. And because they had to manually ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠add and subtract every single figure using wooden counting rods, progress was agonizingly slow. At this rate, it would take an entire year just to review a single ledger from Chungcheong.

"You there! Why did you sum up the digits like that? Recalculate it!"

"M-My Lord! Forgive me!"

Every time I barked an order, the terrified clerks fumbled their brushes, dripping black ink all over the paper. As I sighed in frustration and rounded a corner, my eyes caught a young, low-ranking clerk huddled next to a pillar in the corner.

"...Huh?"

My steps came to a sudden halt. The nobility generally despised mathematics, viewing the handling of numbers as a vulgar task fit only for lowly merchants. Consequently, most of these clerks merely copied the ledgers mechanically. But this boy was different.

He wasn't even using counting rods. He simply stared at the complex figures in the ledger, casually scribbled the final sum onto a blank sheet of paper, and flipped to the next page.

"You. Come here."

Startled by my call, the boy immediately threw himself flat onto the floor.

"P-please spare my life, Assistant Minister! If I have committed some wrong..."

His wide, terrified eyes darted around like a cornered stray dog, and his pitifully thin frame trembled like a leaf in the wind. He looked like someone who had spent his entire life rotting in the dusty corners of the Ministry of Taxation.

"That ledger just now—how did you sum it up without using counting rods? If you merely guessed, I will have your head for disrupting state affairs."

At my threat, the boy stammered in tears.

"I-I did not guess... It is just that when I look at the ledgers, the numbers seem to cluster together in my head, and the answer simply appears on its own..."

I snatched the ledger he had just finished and quickly ran the calculations in my head.

...It was flawless. A perfect mental calculation without a single digit out of place. And to do it at such speed while reading these chaotic, handwritten Joseon records?

Holy crap, he's a mathematical genius.

Back at the National Tax Service, I had managed countless elite data analysts, but I had never seen anyone with such raw, instinctive mathematical talent. I gripped the trembling boy's shoulders firmly.

"What is your name?"

"G-Gaetdong-i, My Lord."

"Gaetdong-i?"

"Yes, yes. Since I am of lowly birth..."

What a terrible name, even for a commoner. I clicked my tongue, cutting him off, and let out a broad smile. I had just unearthed Joseon's greatest data analyst from the dirt.

"Gaetdong-i."

"Yes, My Lord!"

"Starting today, you are my direct apprentice."

"...Pardon?! Apprentice...?"

"While the noblemen look down on numbers to study their useless philosophy, you and I are going to taste the power of real money." I pressed the brush back into his hand and whispered softly. "We leave for Chungcheong Province tomorrow. Pack your things. We are going to seize every single hidden ledger and estate belonging to the Chief State Councillor's family."

Leaving the utterly dazed Gaetdong-i behind, I turned on my heel. It was time to sever the Achilles' heel of Hwang Hui, the most formidable politician in Joseon.