Side Quest: Dungeon Exploration Failure and Strategy (5)
Dungeon.
A kind of "monster den" that appeared across the world after the unprecedented cataclysm in human history.
In the game, the Yeongdeung Mountain Dungeon was called Mad Mage Kate's Lab.
Long ago, a mage named Kate discovered the dungeon and forced through experiments that captured humans and monsters alike, fusing them into single organisms. To keep outsiders from interfering, she filled the interior with traps and released monsters, turning the place into a fortress. Heroes had already attempted a raid once and failed — as a dungeon, its performance was excellent.
Especially the traps.
Falling boulders. Collapsing floors. Tentacles erupting from below. Ceilings that caved in. Traps that randomly teleported people…
In the Yeongdeung Mountain Dungeon, the traps were more dangerous than the monsters.
But then again—
A trap only shows its true worth when you don't know it's there, right?
So what if — just hypothetically — you walked in already knowing almost everything? The layout, the traps, the monsters, the fixtures, the mechanisms?
"Hold on a second."
Seven people were following the advance team's trail deeper into the Yeongdeung Mountain Dungeon when Lee Jinhyuk, who had been carefully scanning the surroundings as he brought up the rear, suddenly called everyone to a halt.
"Could we stop here for a moment?"
Oh Jeongnam and Park Sangcheol stopped and looked back.
Why was he calling them out of nowhere?
"What is it?"
"Could you take a look over there?"
Jinhyuk pointed a finger at a patch of ground a short distance away. The others turned their eyes to the floor and realized that a rectangular tile-like section was protruding — very, very slightly.
"I think that's a trap."
"I'm sorry, what?"
Oh Jeongnam, who had been leading from the front as the header — responsible for spotting traps and keeping the team safe — stared straight at Jinhyuk's face.
A trap?
This corridor was a place the advance team had already passed through. Jeongnam himself, as the scout, had found nothing. And now an academy trainee who had only just enrolled at Union was claiming to have found a trap that a veteran like him had missed?
"If you look closely, you can see a structural mechanism in the gap in the floor. It looks like a pressure-activated trap."
"…"
Jeongnam frowned slightly.
He'd spotted that tiny gap with the naked eye?
It was a little hard to believe, but just in case, he slowly examined the ground again. And just as Jinhyuk had said, through a barely open seam he could make out some kind of mechanical device.
He had been checking everything carefully as he led the team — and this was still his mistake as the scout. If they had kept walking, one of the people following behind would almost certainly have triggered it.
"Ah… sorry. I must not have looked carefully enough."
"It's fine. The advance team walked right past this place without noticing either, and it's so dark in here it's hard to see."
Even Jeongnam had to admit the trap was so tightly concealed that it would have been easy to miss. A thorough sweep might have found it, but knowing the advance team had passed through safely, he had unconsciously been a little less careful.
"But Jinhyuk?"
"Yes?"
"Your eye for detail is impressive. How did you spot that in a place this dark?"
It wasn't wounded pride that a pro like him had missed something Jinhyuk found — pure curiosity. Jinhyuk had mentioned he was an archer, and Union was full of talent. Maybe the kid's eyesight really was better than his.
And then—
"I watched the advance team's body-cam footage. That's how I had some idea."
"Oh, is that so?"
Jinhyuk's answer was a little unexpected.
Body-cam… Jeongnam had watched that too.
"No, I watched it as well, but the footage wasn't good enough to pick out trap mechanisms like that."
"Ah, that? I upscaled the video, maxed out the brightness, then split it frame by frame and went through it one by one."
"Excuse me?"
"Doing that, I found about a hundred and eight spots that looked a little suspicious. The ones with a high probability of being traps, I compiled into a separate document and submitted — I believe it was passed along to all of you."
"Ah, yes. That…"
"It's fine. Honestly, even I wouldn't have paid much attention to it. The advance team had already cleared the area, and it was analysis from a hero trainee who doesn't even know the field that well."
Watching Jinhyuk speak so casually, Jeongnam felt a quiet flicker of admiration. Spending an entire day rewatching footage and memorizing it required serious focus and memory. And he had just memorized a hundred and eight suspected trap locations?
Jinhyuk had never set foot in this place before. Even with lantern light, the fact that he could immediately point out a spot he had memorized in this pitch-dark dungeon was genuinely impressive.
Come to think of it, he'd heard the kid's theory scores were outstanding. He'd assumed Jinhyuk was just the type who studied hard enough to get into Korea's top hero academy on written scores alone.
Maybe he hadn't gotten into Union on worthless practical scores after all.
For his first dungeon exploration, he really put in the work.
Jeongnam nodded to himself, settling into a kind of acceptance. The world was full of all kinds of eccentrics and geniuses — people who could memorize something after a single glance, or compute dozens of digits in an instant. Years ago, Jeongnam had even met someone with perfect recall at the Gaonnuri Clan. So he didn't think much of it.
Not long after—
"Kieeee, eeee, eee!"
"Kii, kiii, kiiii."
"Red vampire bats confirmed ahead."
In the distance, bat monsters came winging hard toward them, massive wings beating as they dove straight at the party. Sharp fangs looked ready to tear into flesh and suck blood dry.
"Everyone, combat ready."
Han Seowoo tightened her grip on her whip. They weren't powerful monsters, but there were a lot of them. Being flying beasts, they were highly mobile, and their bloodsucking ability let them regenerate wounds on the spot — fighting mindlessly would burn through stamina fast.
"Uncle Sangcheol, draw aggro from the fron—?"
That was when it happened.
"Wait — you!"
Out of nowhere, Jinhyuk was spraying something like an aerosol into the air above them. Startled by the sudden action, Seowoo frowned hard and moved to stop him at once.
What the hell was that kid doing?!
"Stop messing around and get over he— huh?"
But what was this?
"Ki, eeee? Eeee, eek?!"
"Keeeeeek?! Kerrrrk…!"
"Kiiiik! Iiiik!"
The red vampire bats that had been streaking in like arrows suddenly writhed in distress, their wingbeats falling apart. Several of them failed to fly properly and slammed their heads into stalactites with a hard crack. They hit the floor in a spray of blood and simply lay there trembling. The rest turned tail and fled for their lives.
"What the hell…?"
The situation was thoroughly baffling, but like a veteran she finished off the remaining bats first, then walked over to Jinhyuk.
"What exactly did you do? Why did they react like that…"
"Red vampire bats have extremely developed senses of smell, so they're vulnerable to the scent of certain chemical compounds."
"What?"
"The same way humans react extremely sensitively to a substance called geosmin compared to other animals — and can detect it no matter how diluted it is — those vampire bats are far more sensitive to specific chemicals than other creatures…"
"No, wait, wait."
Faced with Jinhyuk's sudden lecture, Seowoo waved her hands.
"How do you even know that?"
"I read it in a paper recently."
"A paper?"
"Yes. A paper Professor Goo Seokyeon published two days ago… a detailed treatment of the biological evolution of red vampire bats, their traits, and the related dynamics. It was in there."
"Huh."
Seowoo was flustered.
What was this kid even saying?
He'd read a paper on vampire bats recently and learned their weakness? It was already weird that a busy Union hero trainee had been reading some random paper — how had he even expected red vampire bats to show up?
"You — how did you know red vampire bats would appear? They weren't in the advance team's survey data."
"I didn't know."
Huh?
He didn't know?
"I just made some educated guesses."
Jinhyuk continued in a flat, matter-of-fact voice.
"Based on the advance team's survey materials — the environment around Yeongdeung Mountain, the dungeon's internal temperature, humidity, terrain, lighting, monsters, mana density, scale, native plant life, and so on — the kinds of monsters that could inhabit an environment like this came to roughly fifty-three species."
"Uh, right."
"I narrowed those down to the most likely ones, then searched online for their traits and countermeasures and studied as many as I could."
"Y-you did?"
"Of course, I didn't just prepare for red vampire bats. I brought gear for other monsters too."
Without warning, Jinhyuk started pulling items one by one from the massive backpack he had lugged along. A flashlight rated over 100,000 lumens. An ultrasonic repeller. A 170-decibel sonic blast device. Pheromone perfume from a lotus-claw frog. And more.
Items that would be extremely effective against several of the monsters likely to appear in this dungeon.
"…"
So that was why he'd brought such a huge bag.
He'd packed all of this?
Seowoo's face went a little blank with disbelief.
"You found, memorized, and prepared all of this… in a single day?"
"I already knew a lot of it from before. And more than anything, when I asked Yu Seolhyeon, she got everything ready right away, so that was a relief."
Seowoo lost the ability to form words.
"And earlier you said you memorized places where there might be traps the body-cam footage missed. In a single day."
"Yes."
Was this kid insane?
How did you research and memorize all of that in one day?
"They say better safe than sorry, right? Best to prepare everything you can."
"Mmm."
"And the reason I didn't mention any of this beforehand is that I wasn't certain those monsters would appear, and I figured people might think I was weird for no reason."
She couldn't exactly say that wasn't true.
Come to think of it, he said he had compiled research and information, right? No way he did all of that in a single day. Did Yu Seolhyeon feed him intel ahead of time, back when the advance team was raiding?
Either way, thorough preparation never hurt. But she still needed to caution him about acting on his own. Leave it alone and he might keep freelancing.
With that thought, Seowoo was just about to open her mouth when—
"I'm sorry."
"Huh?"
Jinhyuk got there first.
"We have team positions, and I feel like I acted on my own a bit. We got lucky this time — that doesn't mean it would work out next time."
"…Well, that's true."
"Sorry, Team Leader Han Seowoo. From now on I won't move without orders."
"…Alright. As long as you understand."
When he bowed his head first and admitted fault, there wasn't much she could say. On top of that, he had found the trap Jeongnam missed, and his attitude was so earnest it was more than enough to draw the other teammates' sympathy and support.
Like this, for instance.
"Aw, come on, Jinhyuk. Thanks to you we got rid of those bats without any trouble. Seowoo understands too. Right?"
Good-natured Park Sangcheol spoke up in his defense — only natural, given his personality. And if Jinhyuk hadn't found that trap earlier, the one who would have stepped on it was Sangcheol himself.
"It was the first time. Just be a little more careful going forward."
Even Erina the mage shrugged as if it were fine, and Seowoo could only click her tongue inwardly. In an atmosphere like this, saying anything would only make things worse.
"Well… then let's reorganize and keep moving."
And not long after, again—
"What is it this time?"
"This is the only path, but the door…"
The team stopped. A massive metal door blocked the way ahead. On the screen above the opening mechanism, a string of strange numbers was displayed. What was this now? The team fell into thought.
5212 = 0
6202 = 2
9408 = 5
8102 = ?
"A riddle? You've got to be kidding."
"I've heard of dungeons like this, but this feels pretty artificial."
"Should we just smash the opening mechanism? It might open if we're lucky."
"Don't. If something goes wrong, the whole door could lock up for good."
"Hmm. That door looks solid. Breaking through would take a lot of time."
"Ugh, I don't know. Anything that needs thinking is poison to me."
While everyone was trading opinions, Jinhyuk took a step forward.
"I think I know the answer."
"Huh?"
Seowoo was a little surprised.
He'd solved that bizarre riddle?
Already?
"Mind if I try entering the answer?"
"Mmm… well."
Seowoo glanced around at the others for agreement, and they nodded as if to say go ahead. They didn't seem likely to figure it out by thinking longer anyway. Besides, they had three chances — and after everything Jinhyuk had shown so far, there was a sliver of expectation.
"So what's the answer?"
"I'm not certain, but it's probably three."
"Three? Why?"
Seowoo voiced her confusion. She had no idea why it would be three.
"If you think about the pattern in the riddle, it's simple. Count the holes in the numbers as one each."
"Uh… o-okay?"
"Yes. The digits 0, 4, 6, and 9 each have one hole, so they count as one. The digit 8 has two holes, so it counts as two. Like that."
"Hmm…"
It was… a really intuitive problem, in a way. Whether the answer was right or not was another matter.
Seowoo scratched her chin.
"I'll try entering it."
Jinhyuk input the number 3 on the panel. Seowoo watched, wondering how it would go — and then, with a heavy rumble, the massive door began to open.
It was actually the right answer?
"It really was?"
"Honestly, it was a pretty intuitive, one-dimensional riddle, wasn't it?"
"…"
Seowoo chewed her lip. She hadn't even managed that one-dimensional thought. The answer itself was a little ridiculous, but as someone who hadn't managed any real deduction at all, what was she supposed to say?
"Anyway, the door's open, so shall we keep going? There are traces that look like the advance team was dragged off, continuing that way."
"…Yeah. Alright. Let's go."
Seowoo clicked her tongue inwardly and thought.
Honestly, she'd figured it would be enough if this kid just didn't get in the way.
She was going to have to revise that opinion a little.
No — not a little. A lot.
A wide clearing.
A short rest break.
A little apart from the others, Yu Seolhyeon and Lee Jinhyuk spoke in near-whispers.
"Ugh, how was I supposed to memorize all that in a single day for real."
Well — remembering game content from a past life this thoroughly was just as weird. Of course, there was plenty he'd forgotten too.
"Heh heh. Good work. Those excuses about reading a paper in advance… splitting the video into individual frames and memorizing them… they were pretty funny, though."
"…No, the paper was real, okay? It really was published two days ago."
"Oh, was it~? Heh."
"But why does everyone just kind of believe me? If it were me, I'd be staring at them like, what kind of nonsense is this guy spouting?"
"You already built up some credibility by ranking first in theory."
"Come on, even so…"
Yu Seolhyeon, who had been watching Jinhyuk's half-baked excuses the whole time, just laughed softly under her breath.
You have to put the information you got from future sight to use somehow, Jinhyuk.
Right?