I Activated Cheat Mode in a Bizarre Game

Han Sora, Seo Jihyun, and I were in the middle of a lively conversation about Leo—his cuteness and odd habits—when it happened.
Team Leader Park Cheolwoo entered the break room, wearing a slightly tired expression.

"Aah... There you all are. We just received word from headquarters."
All eyes turned toward him at his words.
"First off, the final list of successful applicants for the new Exploration Teams has been confirmed, and team assignments have been completed. Teams 16 through 20—five teams total—have been newly established."

"Oh! Finally! Does that mean our workload’s about to lighten up?"
"...I wouldn’t bet on it."
At Han Sora’s hopeful question, Team Leader Park gave a bitter smile.

Then he turned his gaze to me.
"The candidates you supervised in Group 8… They all passed. They’ve officially been assigned as Exploration Team 16. And the team leader will be the exorcist applicant—Bora."
"Wow, they make an applicant a team leader just like that?"

"It’s my first time seeing it too, but… I believe that was the condition under which she applied."
Makes sense.
I’d wondered why a well-known exorcist—famous for handling monsters alone—would bother applying to Dongto at all. So that’s what the interview was really about.

It all added up now.
I nodded to myself. Given how calm and composed she was in the labyrinth, how effectively she handled unexpected situations, she was more than qualified to lead a team.
She may have lacked raw firepower, but her abilities had versatility—and that mattered just as much.

"And... our team has received a new assignment as well."
Team Leader Park’s voice dipped slightly.
He turned on the briefing screen and displayed it for us. On the screen was a map of a decaying warehouse district near Incheon Port.

"A report just came in about strange sightings in this area, passed along by the local merchants. No confirmed victims yet, but based on the context, it’s likely a monster has appeared."
His words immediately put me on edge.
"Our Team 15 has been tasked with exploring the site to determine if a monster is present, and if so, what kind, and what level of danger it poses. In other words, it’s a scouting mission."
"Team Leader."

Seo Jihyun, who had been quietly listening, adjusted her glasses and spoke.
"Excuse me, but… isn’t that kind of reconnaissance mission usually assigned to Teams 6 through 10 only?"
She was right on the mark.

Our main duties were centered on handling low-risk monsters.
That meant dealing with creatures listed in the manual—monsters we already had information on—or working alongside support teams for containment.
Sending us in alone to an area that might hide unknown threats was a completely different level of responsibility.

Team Leader Park gave a solemn nod.
"...You’re absolutely right, Seo Jihyun. But… do you remember? They told us that with more exploration teams being added, our own assignment scope would be slightly expanded. This seems to be the first case of that happening."
His tone was one of resignation, tinged with unease.

"They haven’t determined the danger level yet, but it’s expected to be Grade 3 or below. I believe HQ wants to test whether Teams 11 through 15 can handle missions at that level."
"Haa... so it’s finally happening."
Han Sora sighed and scratched her head.

The cheer vanished from her face.
Same here. I was just starting to get used to the routine of working here—handling low-risk assignments.
I cautiously raised my hand to ask:

"Grade 3… what kind of monster does that entail, exactly?"
"Oh, right. I suppose I should explain."
According to Park, monsters classified as Grade 1 or 2 were the kind we’d been dealing with so far.

Most of the creatures held in containment cells fell into this category. The chameleon-type monster was one of them.
But starting from Grade 3, monsters gain the ability to create domains.
That included the berserk stone tablet monster—the one that created a space like a quiz show.

Unidentified monster reconnaissance…
There was no telling what we’d find.
Unconsciously, my hand went to the hilt of the return blade on my hip.

I could only hope that the threat we were walking into was still within the range that my sword—and my cheat—could handle.
"And, not that it makes things any better, but this time the field assignment includes a much larger bonus."
"Whew… Alright, my sweet dusty baby, noona’s going to earn us enough ❀ Nоvеlігht ❀ (Don’t copy, read here) for a brand new cat wheel..."

Han Sora mumbled under her breath, sighing.
Scary or not, a higher bonus was good news.
I need to save money—fast.

Things were different now.
There was someone I had to protect.
I wanted—no, needed—to get to Seoul, where monster activity was minimal, as soon as possible. For Leo’s sake.

If Leo ever got caught up in a monster incident, if our delicate little Leo were hurt—
Just the thought made my stomach churn.
We immediately gathered our gear and got into the vehicle.

Our destination: a rundown shopping complex near Incheon Port.
The gray industrial scenery outside the car window felt bleak, almost ominous.
Even the fish market we passed seemed strangely deserted.

"This is the place."
The car stopped in front of a worn-out, three-story commercial building, its location desolate and isolated.
From here, we could see the ocean—likely due to how close we were to the port.

A middle-aged man with a nervous expression was waiting at the entrance. Judging by the way he rushed to greet us, he was probably the building’s owner.
"Ah, thank goodness you’re here! You’re from Dongto, right?"
He hurried toward us, voice strained with anxiety.

"Please, you have to do something! I’m going crazy from the noise upstairs—day and night!"
He pointed up at the second floor of the building.
"The whole second floor’s been empty, but lately we’ve been hearing people laughing, shouting, partying up there! At first I thought I was imagining things, but now the other tenants have all heard it too! They’re scared—they’re closing up early—and I’m too terrified to even go to the second floor myself…"

He was nearly in tears as he pleaded.
"What was the second floor used for, exactly?"
Seo Jihyun asked sharply.

"Huh? Oh… uh, let me think. About ten years ago? It was an illegal gambling den. Got shut down during a police raid, but it was a rowdy, violent place before that."
"...Understood. We’ll take it from here. Please wait somewhere safe for now."
Park Cheolwoo reassured the owner, and we turned toward the building’s entrance.

"Why did you ask about the second floor?" Han Sora asked, keeping her voice low as she waited for the landlord to move away.
"Monsters are always influenced by their surroundings."
She was right.

A former hospital had produced doctor and nurse-type monsters.
And beneath the hotel, there had been a hotel filled with monsters.
Which meant... this time, the monster might be connected to gambling.

When we pried open the sealed metal door on the first floor, a stale, dusty odor hit us—followed by a chilling rush of air.
My hand instinctively went to the return blade again, and I stepped into the abandoned building, tension mounting.
We made our way through the eerie ground floor and climbed the stairs toward the second floor—the one from which the noises had been reported.

At the far end of the second-floor corridor, a heavy iron door stood shut.
Then, from behind the door, a faint voice rang out—
Ahaha… yeah!

"...Did you hear that just now?"
"Yeah, I heard it."
"Not a hallucination, then..."

As we drew closer, the strange sounds and flickering light spilling through the gap in the door became unmistakable.
This place was supposed to be abandoned, and yet from behind the door, we could hear laughter, chatter, and even faint music.
Colorful neon light was leaking out from beneath the door.

"...There’s definitely something in there."
Park Cheolwoo’s voice was tense.
Han Sora swallowed hard. Seo Jihyun already had an item in hand, ready to act.

I tightened my grip on my blade.
Park Cheolwoo took a deep breath and gave us a nod.
Then, summoning his courage, he grabbed the door handle and yanked it open.

KIIIIIIIIIK—
The iron door, clearly unopened for years, shrieked loudly as it swung open.
And what we saw beyond it defied belief.

"...Whoa…"
What lay beyond that door was a massive, dazzling casino—something no one would ever expect to find on the second floor of a run-down commercial building.
An endless sea of slot machines bathed the room in colorful light and blasted loud sound effects. At the central tables, skilled dealers shuffled cards as cheers and groans from players rang out.

And it wasn’t just gambling tables—around the edges of the first floor were pawn shops, convenience stores, restaurants, even a sauna.
The air was thick with cigarette smoke, expensive perfume, and the heat of human activity.
The casino was packed.

Women in glamorous dresses, gentlemen in sharp suits, dealers, bartenders, and waitstaff.
Dozens—no, hundreds—of people laughed, played, drank, and shouted, immersed in the games.
There was no way such a place could exist within the confines of this decrepit three-story building.

"What... is this even..."
Han Sora’s jaw dropped, words failing her.
Park Cheolwoo and Seo Jihyun stared in stunned silence, eyes wide with a mix of shock and confusion.

And I was no different.
Physically, this shouldn’t be possible. There was no way to explain this unless it was magic—or a hallucination.
We didn’t need to say it aloud, but all of us knew, beyond a doubt, what this place truly was.

...This is a monster.
No question.
This entire spectacle—this impossible, dazzling casino—was either an illusion crafted by a monster, or a separate dimensional space it had created.

At minimum, it was a Grade 3 monster.
And we had just stepped into the heart of its domain.