The day after we decided on our course of action—the second day of Golden Week—we finally reached the 29th floor.
Standing before the massive, double-leafed metal doors at the end of the stairs, I checked my watch and let out a small sigh.
"It took four hours one way, just like we expected..."
"What’s the call?" Yuji asked.
"If we start a boss battle now, the timing is going to be tight..."
I stared at my watch with a grimace. We had researched the area boss at the Dungeon Association beforehand, but knowing the theory was different from knowing how long the actual fight would take. With our pre-arranged return time fast approaching, I was torn between retreating and pressing on.
"We’ve come all this way," Hiiragi-san said. "I’d like to at least give it a try, but..."
"So, you’re in favor of the boss fight, Hiiragi-san?"
"It’s not so much a 'desire' as it is a lingering feeling. I’d hate to walk away now."
"I see."
She was reluctantly in favor. I could relate; after spending so much time reaching this point, I understood why she didn't want to just turn around.
"I did make some preparations assuming we might fight the boss, so it’s not impossible if we want to go for it. What about you, Yuji?"
"Personally? I want to do it."
"Yuji..."
He was clearly in the 'pro-challenge' camp.
"Of course, I know the return time is close. We’ve mapped the route this far, so I know that if we come back next time, we could probably squeeze out enough time for the fight."
True. As Yuji said, we didn't have to force a boss battle now. We could come back with more time to spare. The stairs weren't sealed, and the boss wasn't breathing down our necks yet.
"Then shouldn't we pull back for now? Knowing when to quit is part of the job, right?"
"But we won't always have the luxury of avoiding combat whenever it suits us, will we?"
"Well... I suppose not."
I was at a loss for words. Right now, we were only able to choose our battles because of the sheer gap between our strength and the monsters on the lower floors. There was no guarantee that would remain true as we went deeper.
Yuji continued, his eyes fixed on the massive metal doors.
"I suspect this battle is the type where once you pass those doors, you can't come back out until it’s settled."
"A deathmatch, you mean?"
"Probably. That's exactly why I want to try it now. While we still have a margin of safety in our strength, I want to experience an unavoidable battle under the pressure of a time limit."
"..."
Geez... he has a surprisingly bellicose look on his face. Isn't his mindset a bit too much like a battle-hungry warrior race?
I mean, I followed his logic, but still... experiencing combat under disadvantageous conditions was probably a good idea in the long run.
"Um, Hiiragi-san?"
"Yes?"
"Yuji feels this way, and I get what he’s saying... but what do you think?"
Since the "disadvantageous conditions" factor had been added to the mix, I wanted to re-confirm her stance. She had been leaning toward it anyway, so I could guess her answer, but...
"I’ll cast my vote for going ahead. It’s true that we’ve had very few fights where the odds or conditions weren't in our favor."
"I guess so."
"In that case, I think I should experience it now. Disadvantageous conditions mean more mental pressure, and pressure leads to impatience. It’s dangerous to encounter a monster you can only just barely handle if you aren't used to fighting while feeling that kind of heat. Besides, while the return time is a constraint, it’s not a fatal one. Like Hirose-kun said, it’s better to experience this while we still have enough strength to handle it with room to spare."
As expected, Hiiragi-san was also in favor. That made two votes for the boss battle. Since I was also leaning that way, the matter was settled.
I looked at them both and gave our conclusion.
"Alright. Let's challenge the area boss."
"Yeah."
"I'm ready."
They both nodded in agreement.
Phew. Well, that meant we had to hurry up and prepare. Once the decision was made, I felt a slight twinge of anxiety as I checked my watch again. So this is the mental state she meant...
In front of the massive doors engraved with relief-like patterns, we made our final preparations during a brief rest. The time on my watch had already ticked past our intended four-hour turnaround point. Every minute the boss battle dragged on would be another minute added to our late return.
I exhaled slowly, composed myself, and looked at the other two.
"Shall we?"
"Let's do it."
"Yes."
We stepped toward the massive doors with me in the lead, maintaining a formation that allowed us to check for traps. As I observed the entrance using Appraisal Analysis, a look of exasperation crossed my face.
"What a pain..."
"What is it, Daiki? Is it trapped after all?"
"No... no traps."
"Then what's the problem?"
"There are no traps, but these things are just incredibly heavy."
I pointed at the doors and shared the appraisal results.
"Heavy?" they asked in unison.
"Yeah. Even just one side of the door weighs nearly ten tons."
"Ten tons... That's about the weight of a large truck."
"Right. And since the bottom of these thick doors is flush against the ground, the friction acts as direct resistance. They're going to be a nightmare to push open."
"Ugh..."
"So, to open this, we need the strength to move a ten-ton object?"
Yuji grimaced, and Hiiragi-san let out a small cry of surprise. I nodded silently to her question.
"There is an auxiliary opening mechanism, though. See that indentation on the surface?"
"An indentation?"
Their gazes followed my finger to a relief with a hole about the size of a ping-pong ball.
"It looks like the mechanism activates if you insert a Core Crystal of the right size into that slot."
"A Core Crystal... At that size, would it be the one from the big bear we fought on the 28th floor?"
"Most likely. For items you can find on the lower floors, that’s probably the only one that fits."
The big bear—the giant bear from the 28th floor. It had heavy blows from its powerful arms, agility that defied its massive bulk, and high defense thanks to its thick fat and fur. Most importantly, it had been significantly smarter than any monster we had encountered previously.
"Technically, we can force them open without the mechanism... what do you want to do?"
Core Crystals were generally traded by weight, so even a big bear’s drop wasn't exactly a priceless treasure. I asked if they wanted to use it.
"Can we actually open them without it?"
"With our current strength, I think we could manage if we pushed with everything we had. But it’s not a great idea to waste that much energy right before a boss battle."
"True."
Yuji and Hiiragi-san both nodded. If we could avoid unnecessary exhaustion just by spending a Core Crystal, it was a small price to pay.
"This is probably a way to screen challengers. The opening mechanism is a bit of a saving grace, but..."
"You mean anyone who can't move these doors isn't worthy of fighting the boss?"
"Probably. As an explorer's level rises, their physical abilities naturally improve. Even a solo explorer could move this weight if they used physical enhancement skills. And a full party could just push together. It’s a simple way to weed out the weak."
"I guess that makes sense... but why bother screening them? I’d understand if the Association set this up, but the dungeon was like this before humans arrived, right?"
Yuji’s doubt was valid. Why would the dungeon itself care about screening challengers? I couldn't think of a concrete reason either, and the mystery felt like a nagging itch in my mind.
"Who knows?"
"That’s all you’ve got?"
"I can't help it. I really have no idea."
Yuji looked dissatisfied, but I didn't have a better answer for him. If I had to guess, maybe the dungeon dislikes the pointless waste of explorers. Looking at the "tutorial-like" nature of the surface floors, perhaps it views explorers being killed due to reckless challenges as an undesirable outcome.
As Yuji and I fell into silence, Hiiragi-san clapped her hands together.
"Alright, that’s enough. Let’s save the philosophy for after we’re back on the surface. Talking about it now won't give us an answer, and our clock is ticking."
"Ah, sorry."
"My bad."
We both looked sheepish and apologized. She was right; having an endless debate with no conclusion was a poor use of our limited time.
"So, what's the plan? Are we using the Core Crystal?"
"Uh, yeah."
"I think we should."
"Then it’s settled. Kokonoe-kun, could you produce the Core Crystal?"
"Right away..."
Feeling a bit pressured by her unyielding tone, I hurriedly searched through my Spatial Storage and pulled out the big bear's Core Crystal. Hiiragi-san’s smile was a little intense.
"Here you go."
I timidly handed the crystal to her like a tribute. She took it and pointed at the indentation for one last check.
"I just put it in here, right?"
"Yeah. That should trigger the mechanism. The door itself is a kind of magic item, and the crystal acts like a battery."
"I see. Here goes, then. Be on your guard; something might jump us the moment it opens."
She pressed the Core Crystal into the slot. Yuji and I drew our weapons and braced ourselves, while Hiiragi-san quickly moved back and leveled her spear. We avoided standing directly in front of the doors, positioning ourselves to the sides. I didn't expect a trap, but I didn't want us wiped out by some freak opening blast that ignored all the rules.
Several seconds passed in silence.
"...Nothing's happening."
The moment Yuji grumbled, the crystal began to glow. The light rippled outward through the engraved patterns of the relief until the entire door was bathed in a soft radiance. With a heavy, grinding sound, the doors began to swing inward. A few seconds later, they were wide open.
"It worked."
"Yeah, they’re open."
"Here we go."
We watched the open doorway for a moment before nodding to one another.
"Alright, let's move. We don't know the layout inside, so stay sharp."
"Got it. Daiki, check for traps as soon as we step in. I want to know the floor is safe before we focus on the boss."
"Understood. Hiiragi-san, any signs of life?"
"One monster presence in the room."
"Just one?"
"Yes. Only one right now. But something could pop up later, or come in from another room."
That was a real possibility.
"Got it. Stay alert and stick to the plan."
"Right. We have a time limit, but there's no need to panic."
"Exactly. We’re past the turnaround point, but let's keep our heads."
Yuji and Hiiragi-san were intentionally emphasizing the time limit. I knew they were doing it to maintain the mental pressure we had agreed to train under, but it still made my heart hammer against my ribs.
I took a steadying breath, and we followed Yuji into the room.
Inside the vast, dimly lit chamber, our lights cut through the gloom to reveal a single monster standing at the far end.
It was over two meters tall, with a crimson body of corded muscle. It wore simple black armor and gripped a thick metal club as long as itself. A single horn jutted from its forehead, and sharp fangs peeked from its mouth.
"An ogre."
The word escaped my lips as I named the monster standing before us.