Thick filth clung to the soles of Lee Jin-gu’s hiking boots, tugging at every step.
Each breath scraped his lungs with the stench of stagnant water and animal waste. Instead of grimacing, Lee Jin-gu shortened his breathing and pressed himself close to the wall.
The blue message window that had appeared before him soon dissolved into the air. There was no dramatic change—no sudden heat flooding his body or explosive surge in strength.
Only silent darkness and an unbearable stench filled the sewer passage.
Does it want me to kill something first?
Lee Jin-gu clicked his tongue softly and turned his gaze toward the darkness.
Screeeech!
A spine-chilling metallic shriek erupted from a corner.
A mutant rat as large as an adult man’s forearm sprang out, its red eyes gleaming. It kicked off the muddy ground and launched itself toward his thigh.
After ten years of working C-rank hunting grounds, Lee Jin-gu’s mind had already calculated its trajectory perfectly.
The timing of its leap.
Its posture in midair.
The time remaining before its pointed teeth reached his trousers.
He could already picture himself dodging elegantly and delivering a counterattack.
The problem was his body.
Oh, right. I’m a tin can with a mana capacity of twelve.
His muscles could not keep up with his mind’s commands.
His reflexes were half a beat too slow. If he forcibly twisted his body now, he would either roll his ankle or pull something in his back.
Lee Jin-gu did not attempt a flashy dodge.
Instead, he slid one foot into a moss-covered gap along the damp sewer wall. His weight dropped downward, naturally lowering his body toward the ground.
The mutant rat’s teeth sliced through the air and brushed past the tips of his hair.
At that exact moment, Lee Jin-gu reversed his grip on the dagger and drove it upward beneath the rat’s jaw.
Stab!
The cheap dagger pierced the mutant rat’s vital point with a dull tearing sound.
It was a fatal strike delivered from an unavoidable angle, made possible solely by his extensive combat experience.
Screek...!
The creature released a dying cry and dropped limply to the ground.
The metallic scent of blood surged into the air.
Before Lee Jin-gu could pull out his dagger and catch his breath, a faint gray mist began rising from the mutant rat’s corpse.
It hovered in the air for a moment before flowing directly into his fingertips.
Ding!
A blue window flashed into existence alongside a mechanical chime.
[You have collected the trace of a Mutant Rat.]
[Strength +0.01]
[Agility +0.01]
[Presence Detection and Dark Adaptation have slightly increased.]
Lee Jin-gu quietly studied the hand holding his dagger.
He could feel a faint warmth spreading from his fingertips and flowing through his veins.
If someone else had seen the notification, they might have scoffed and cursed.
A mere increase of 0.01.
Even killing a hundred monsters would only raise the stat by one point.
But the perspective of a ten-year veteran who had survived countless hardships was different.
“Holy shit.”
A disbelieving laugh escaped his lips.
I don’t need to burn through expensive mana stones or drink potions worth tens of millions of won? My stats will increase indefinitely as long as I keep killing things?
And stats were not the only reward.
He had absorbed the environmental adaptations of a mutant rat that spent its entire life crawling across sewer floors.
After blinking several times, Lee Jin-gu found that the dense darkness—which had appeared murky only moments earlier—had grown noticeably clearer.
The distant dripping of water reached his ears.
Amid it, he could distinguish dozens of tiny claws scratching against the ground.
This skill is practically made for grinding.
A predatory smile spread across his lips.
He might not possess spectacular explosion magic or an instant-kill technique, but no ability could be better suited to surviving in a cramped, filthy environment like this.
“Ten thousand won per rat.”
Lee Jin-gu crouched and tightened his mud-covered hiking boots once more.
“I’m cleaning out this entire sewer tonight.”
***
The hunt was not a simple one.
Lee Jin-gu was not foolish enough to charge into the middle of a rat swarm with nothing but a knife.
He first examined the direction of the flowing water and identified the routes where the creatures’ scent was strongest.
He gathered mud and garbage against one side of the narrow passage to form a crude barrier. Then he embedded sharp fragments of broken wire mesh into the chokepoint the rats would be forced to cross.
It was a rough but reliable trap.
Screeeech!
Whenever mutant rats drawn by the scent of blood became caught in the trap, Lee Jin-gu’s dagger mercilessly emerged from the darkness.
Stab! Slash!
There was no unnecessary swordsmanship.
Only vital points.
The eyes, the nape, and beneath the jaw.
He targeted only the places that were easiest to pierce and would kill them the fastest.
[You have collected the trace of a Mutant Rat.]
[Strength +0.01]
[Agility +0.01]
[Dark Adaptation has slightly increased.]
Notifications continuously filled the corner of his vision.
As the hunt continued, his previously sluggish F-rank body gradually began moving as smoothly as an oiled machine.
A value of 0.01 was small, but once those minute improvements accumulated, the response speed of his muscles changed noticeably.
He could sense the rats more clearly in the darkness, and the strain on his wrist whenever he swung the dagger steadily diminished.
“Nine.”
Slash!
“Seventeen.”
Stab!
“Thirty-two.”
It was a thoroughly repetitive process, like the work of a butcher standing in a slaughterhouse.
Lee Jin-gu’s old outdoor clothes were already ruined by dark blood and splattered mud. The stench had seeped into his body and made him gag, but he did not stop.
Every one of these is money for Father’s hospital bills and Mother’s new shoes.
Strangely enough, calculating the money in his head filled him with strength.
Before his regression, he had felt hollow even after completing requests worth tens of millions of won.
Now, however, every ten-thousand-won rat tail he cut off left him feeling deeply fulfilled.
His hunting speed steadily increased.
He finished off the rats caught in his traps, pursued those attempting to flee, and ended their lives.
As the collected traces accumulated and his body adapted to the environment, his movements became increasingly seamless.
Before long, the old burlap sack he had brought with him had grown heavy and swollen.
“One hundred.”
Lee Jin-gu severed the final rat’s tail and shoved it into the sack before straightening his aching back.
His wrist throbbed, and his legs trembled.
Yet his bloodshot eyes shone with more vitality than ever.
“Good work. Time to go.”
After briefly praising himself, Lee Jin-gu wiped the blood from his dagger on his trousers, put it away, and left the sewer without hesitation.
***
The morning sun rose over the city’s outskirts.
The twenty-four-hour payout office operated under contract with the Hunter Association was crowded with low-ranked hunters returning from their early-morning jobs.
They smoked with exhaustion etched across their faces or sipped coffee from the vending machine.
Just then, someone approached along with an eye-watering stench.
“Ugh, fuck! What the hell is that smell?”
“Damn, did someone fall into a septic tank?”
The hunters near the entrance grimaced and covered their noses.
It was Lee Jin-gu, caked from head to toe in black blood and sewage.
The yellow-haired man and his companions who had picked a fight with him at the late-night request board were also there.
When they saw Lee Jin-gu’s condition, they burst into laughter and pointed at him.
“That bastard actually went rat hunting. Hey, did you at least earn enough for your hospital bill? Your medicine will probably cost more, you moron.”
“Look at him. He must’ve spent the entire night rolling around in the sewer.”
It was predictable ridicule.
Without sparing them a glance, Lee Jin-gu silently approached the payout counter.
“I’d like to collect my reward.”
The receptionist, who had been dozing behind the counter, jolted awake and quickly covered his nose.
“God, that smell! Stand farther away when you talk! What did you bring back?”
When the receptionist snapped at him, Lee Jin-gu removed the heavy burlap sack from his shoulder and dropped it onto the counter.
Splat!
The mouth of the sack came loose from the impact, spilling its contents across the counter.
“Eek!”
The receptionist stumbled backward as if he were about to faint.
A heap of blood-soaked mutant rat tails had spilled across the counter.
Even at a glance, there were far more than one or two.
The receptionist’s face turned pale as the nauseating metallic stench radiated from the tangled pile.
“W-What is all this?”
“Mutant rats from the Sector D sewer. Ten thousand won each. There are one hundred.”
“O-One hundred? In a single night?”
The receptionist’s eyes widened.
It was almost impossible for an F-rank hunter to kill one hundred mutant rats overnight.
The yellow-haired group, who had been snickering behind him, stared at the pile of tails with their mouths hanging open.
The receptionist struggled to hide his bewilderment as he tapped at his tablet.
“J-Just a moment. Did you really kill all of these yourself? You didn’t find them somewhere, did you?”
“If you’re suspicious, go to the sewer and inspect the site yourself.”
“No, it’s just that under the regulations... When someone brings in such a large quantity at once, we have to deduct twenty percent for disposal costs and processing fees—”
It was a common trick used by subcontractors to skim money from inexperienced hunters who looked easy to exploit.
Before his regression, Lee Jin-gu might have stammered helplessly and allowed them to steal two hundred thousand won from him.
But now, he pulled a bloodstained smartphone from his pocket and slapped it onto the counter.
The screen played footage of the corpses he had periodically recorded while hunting in the sewer the previous night.
“Article Four, Paragraph Two of the Hunter Association’s Standard Subcontracting Agreement. For requests involving the extermination of small monsters, the full reward must be paid immediately once the required proof has been submitted and verified.”
Lee Jin-gu’s voice was quiet and composed, yet it possessed an unyielding weight that bore down on the listener.
“Deducting disposal costs only applies when collecting the remains of medium-sized monsters ranked C or higher. This request clearly states that severed tails must be submitted as proof, so what processing fee are you talking about?”
“W-Well, that’s...”
“If you’ve confirmed the number of tails, pay me exactly one million won in cash without deducting a single thousand-won bill. If you refuse to follow the regulations, I’ll send this footage straight to the Association’s complaints office and report you for violating your subcontract.”
Thick beads of cold sweat formed on the receptionist’s forehead.
He did not know where this man had come from, but Lee Jin-gu had memorized the regulations and carried himself with an intimidating confidence.
He was clearly not someone who could be pressured into accepting a reduced payment.
“A-All right! I’ll give it to you! I’ve finished verifying everything!”
The receptionist hurriedly opened the safe, counted a bundle of crisp fifty-thousand-won notes, and stuffed them into an envelope.
“Here! One million won! Count it yourself!”
Lee Jin-gu accepted the envelope and flicked the stack of bills with his fingers.
The substantial weight of the money filled his hand.
Only then did a faint smile appear on his lips.
This one million won, earned entirely through his own efforts, felt far more valuable than the tens of millions he had once received for surviving a large-scale Gate.
“Much appreciated.”
Lee Jin-gu tucked the envelope deep into the inner pocket of his jacket and turned away without hesitation.
After leaving the payout office, he faced the morning sunlight and stretched his entire body.
Exhaustion from hunting through the night crashed over him, leaving him desperate to collapse somewhere and sleep.
Yet his feet carried him somewhere other than home.
Only one thought occupied his mind.
His mother’s old shoes, carelessly left in the entryway, their worn soles on the verge of developing holes.
With every step, the envelope containing one million won thumped heavily against his chest.
“I should stop by the market first.”
Lee Jin-gu’s footsteps were lighter than ever.
His old outdoor clothes were torn and reeked of blood, but imagining his mother’s delight upon receiving a comfortable pair of new shoes made a quiet laugh escape him.
He walked toward the traditional market that opened early in the morning without the slightest hesitation.
Instead of pursuing the path of some grand hero, he was delighted simply by the fact that he could replace his mother’s worn-out shoes.
His hand cheerfully patted the pocket containing the money.
Before long, Lee Jin-gu reached the entrance of the traditional market as merchants began raising their shutters one by one.
The savory aroma drifting from a soup-and-rice restaurant mingled with the lively voices of vegetable vendors and filled the market alley.
Ignoring the people glancing at him because of the bloody smell surrounding him, he headed straight toward a shoe store.
Shoes of every color were displayed at the front of the shop.
Lee Jin-gu immediately pointed toward the softest-looking pair of gray sneakers at the center of the display.
“Excuse me! I’d like these gray sneakers in size 235. Give me the pair with the best cushioning.”
Startled by the sight of a young man covered in blood first thing in the morning, the shopkeeper took a step backward.
“Good heavens, young man. What happened to you? Were you injured somewhere?”
“No, I just got some dirt on myself while working. Please bring out the shoes first.”
Lee Jin-gu answered casually as he removed the envelope from his inner pocket.
He pulled out a crisp fifty-thousand-won note.
At the sight of the money, the caution on the shopkeeper’s face faded, quickly replaced by a merchant’s smile.
“Are they for your mother? What a devoted son. Wait right there. I’ll bring you a new pair from the storeroom.”
While the shopkeeper retrieved a fresh box, Lee Jin-gu examined his reflection in the store mirror.
His appearance was appalling.
His entire body was stained with mud and blood.
But the eyes of the man in the mirror looked clearer and more resolute than they ever had before his regression.
“Here you are. I packed them nicely in the box. And here’s your change.”
“Thank you. I hope business goes well.”
Lee Jin-gu carefully cradled the box in his arms and left the market.
His stomach growled loudly.
After spending the entire night fighting rat swarms, it was only natural that he was starving.
As he walked toward the bus stop, he lightly patted the box in his arms.
“I’ll earn the money for Father’s hospital bills tomorrow night.”
His muttering contained cheerful energy rather than exhaustion.
Before boarding the approaching bus, Lee Jin-gu looked up at the clear morning sky and clicked his tongue softly.
“I should take a shower as soon as I get home. I smell fucking awful.”