After stowing our belongings in a cardboard box, the staff member produced two small plastic items from his uniform pocket—roughly the size of Zippo lighters—and handed them to us.
"Take these with you."
"...What are they?"
"They're for giving up... rescue signal transmitters. If you're in the middle of the challenge and decide you've had enough, don't hesitate to remove the cover and press the button inside."
Yuji and I examined the devices. A faint seam ran along the side, indicating a lid that could be slid open. When I tried it, a single red button sat inside, practically begging to be pressed.
"If you press that button, the facility's emergency lighting will turn on. Stay exactly where you are and wait for a staff member to come and retrieve you. If you move around, it'll only delay the rescue."
"...Understood."
"And of course, the moment you hit that switch, you're disqualified."
A reasonable precaution, all things considered.
"That’s truly the end of the explanation. I’m looking forward to seeing how you do."
"Thanks. We'll give it our best shot," Yuji replied.
With that, the staff member opened the entrance gate.
After giving him a brief nod of thanks, we both closed our right eyes and stepped across the threshold into the Advanced Zone.
It was dark. That was the first thing Yuji and I felt as we entered the course. Compared to the bright lights of the lobby, the path ahead—lit only by the dim glow of low-power safety lights—was a void of pitch black. From the sensation beneath my boots, I could tell the ground was covered in grass, likely artificial turf.
We opened our right eyes, which we had kept closed to preserve our night vision. While we weren't fully adjusted yet, we could see much more clearly than we could with our left eyes.
"Keeping one eye closed was definitely the right call."
"Yeah. I didn't expect a pitfall trap to be waiting the moment we stepped inside..."
Yuji and I stared down at the floor. It was a trap designed to genuinely eliminate intruders. Clearly, the Advanced Zone operated on a different level than the previous ones.
"If we'd just strolled in thinking our eyes would eventually adjust, we would've been in that hole before we knew it."
"Yeah. It looks like we'll have to stay sharp and treat this seriously from here on out."
Bracing ourselves, we prepared to tackle the course with the same mindset we used for a real dungeon. We stopped for about thirty seconds, letting our eyes fully adapt to the gloom. When you can't see, your ability to gather information drops to almost zero.
Despite the time limit, rushing was a recipe for failure. Even if it cost us a minute, this preparation was essential.
"...Alright, I'm good. How about you, Yuji?"
"I'm ready."
We had spent about a minute acclimating to the dark.
"Shall we?"
"Yeah. Let's go."
Yuji and I split to the left and right to bypass the pitfall. We could have jumped over it, but a second trap had been meticulously placed at the landing spot.
"A falling ceiling... a double trap, then."
I looked at the ceiling just ahead of the pit. The texture of one specific section differed from the rest; there was no mistaking it.
"If someone were setting traps to seriously repel intruders, they wouldn't stop at just one... There's probably a pressure sensor in the floor right where you'd land after jumping... Whoops."
"A tripwire too? They’re really going for it right from the start."
Yuji and I stepped over a black-painted wire, avoiding it with ease.
"Yeah. This wire is likely meant for the people who let their guard down after avoiding the ceiling and the pit. Daiki, don't relax."
"I know."
Even after clearing the entrance, we didn't let up. We scanned our surroundings with clinical caution. Unlike the earlier zones, the area was thick with vegetation—perfect for concealing mechanisms. The difficulty of spotting traps had skyrocketed.
"Reminds me of Genya-san's training..."
"Yeah. This isn't going to be straightforward."
It wasn't quite as brutal as the curriculum at Genya-san's place, but it was leagues beyond the Beginner or Intermediate Zones. In those sectors, the facility had left subtle hints to help explorers find the traps. Here, there were none. We weren't meant to find clues; we were meant to sense the danger and react on our own.
I could see now why only one group had ever cleared this course.
"That said, it's not like it can actually stop us."
"True. Well then, let's go find our treasures."
"Right."
After confirming the immediate area was clear, we consulted the map to check the item locations.
"The nearest one is... that way."
I pointed toward the right.
Unlike the previous zones, the Advanced Zone wasn't partitioned into rooms. The entire building was designed as one massive, open area. There was no specific order required for collecting the items.
"Let's aim for that one first, then."
"Yeah."
Moving with wary steps, we began our trek to the right.
I disarmed the weight sensor on the pedestal and retrieved the item. It was a key marked with the number 5. That made six.
"Phew... only one left."
"Yeah. We still have fifteen minutes on the clock. At this rate, we'll clear it no problem."
"We can't get overconfident, but yeah, it's looking doable."
I tucked the key into my pocket and checked the map for the final location. Correlating our position with the diagram, I pointed toward our destination.
"...It's over there."
"Over there? If we go straight, we'll hit a pond. If it's on the far side, we'll have to take a long detour..."
"Actually, Yuji, looking at the map... the last item is in the middle of the pond."
"...In the pond?"
Yuji leaned in to squint at the map himself.
"You're right. According to this, the item is definitely smack in the middle of the water."
"Right?"
"..."
"..."
Yuji shot me a grimace. I wasn't exactly thrilled about wading into a pond either. However, if we wanted to clear the Advanced Zone, we had to get that item.
"Well, let's just go take a look first."
"Yeah, let's check the site."
Feeling a bit gloomy, we headed toward the final objective.
Navigating around the remaining traps, we eventually reached a circular pond about twenty meters in diameter. In the very center sat a small island.
"That island is the final placement point."
"Looks like it... So, what's the plan? Are we wading in?"
"I’d rather not..."
Standing on the shore, we debated our options. I couldn't bring myself to agree with Yuji's half-hearted suggestion. My intuition told me that the moment we set foot in that water, something nasty would trigger.
"I was joking, obviously. There's no way I'm walking into a pond when I don't know what traps are lurking under the surface."
"I figured."
It seemed Yuji was on the same page.
"But that brings us back to square one. How do we get over there without getting wet?"
"Yeah... I don't see anything like a bridge... wait. Hey, Yuji. Look over there."
"Hmm? What is it?"
"There! It's hard to see in this light, but isn't that a boat hidden in those bushes?"
I pointed toward the brush on the far side of the shore.
"A boat... oh, I see it!" Yuji exclaimed.
"That's a boat, right?"
"Yeah. It's small, but that's definitely a boat."
"I guess they want us to use that to cross?"
Since there were no bridges, providing a boat made sense as a solution, but...
"...No way. A tool that obvious has to be a trap."
"My thoughts exactly. It's probably rigged to go off the moment we get in."
"Most likely... Well, let's go check it out anyway."
Assuming it was a trap, we walked around the perimeter to inspect it. As we walked, we looked for any other way to reach the island.
"A running jump is out," I muttered.
"Yeah. They've perfectly lined the shore with traps. You can't get enough of a lead-up without hitting one, so you'd just end up face-planting into the water."
After circling halfway, we confirmed the shore was a minefield. A running long jump was physically impossible given the layout.
"We could probably make it with a standing jump... but that would be too conspicuous."
"Yeah. A ten-meter standing long jump? Even for an explorer, that's an insane record."
During the school's physical fitness test, the average standing long jump for a non-explorer was just over two meters, while explorers averaged around four. Jumping double that distance from a standstill would be a neon sign announcing our levels were off the charts. Doing that in a facility run by the Dungeon Association would invite nothing but trouble—especially since we were already under scrutiny for the ogre incident.
"If there were some stepping stones, we could hop across without standing out..."
"Yeah, but there's nothing like that here."
We reached the boat.
"Whoa, it's tiny. Is this a one-person craft?"
"Looks like it. Can you even make it to the island in something this small?"
A brand-new shipping crate and various packing materials were scattered around the boat, almost as if the facility were shouting about how "new" and "safe" it was. After confirming there were no immediate traps, we hauled it out from the shadows. It was a plastic, assembly-type boat, and it felt surprisingly light.
"Hey, Yuji. Why don't you take the first shift?"
"No, no, I insist. You go ahead, Daiki."
"..."
"..."
We both smiled at each other while refusing to budge. There was no way either of us was getting into a boat that looked this suspicious. Especially an assembly-type—I was terrified the joints would give way the moment I put my weight on it, sending me straight to the bottom.
Since we were at a stalemate, I proposed a compromise.
"Let's just float it and see what happens."
"Good idea. If it stays afloat for a while, we'll know it's at least seaworthy. We can decide who gets in after that."
It was the most logical way to test for a trap. If it were rigged, the water itself might trigger the mechanism.
"Alright, on three."
"Ready."
"One, two... heave!"
We shoved the boat into the water. It bobbed gently, swaying left and right, but it didn't seem particularly unstable.
"...Seems okay."
"Yeah. But we haven't put any weight in it yet. We need to see how it handles a load."
"True. In that case... those should work."
I grabbed the rope attached to the bow and pulled it halfway back onto the bank. We gathered several large ornamental stones from the shore, loading the boat until their combined weight matched that of a person. Then, we pushed it back out.
"Hey, Yuji?"
"...What?"
"Is that boat... sinking?"
"...It's definitely sinking."
"I thought so."
Right before our eyes, water began gushing over the stern. The boat started to submerge with alarming speed. Within a minute, it had capsized and settled on the pond floor, with only a tiny sliver of the hull visible above the surface.
"...I'm really glad we didn't get in."
"...Yeah. Seriously."
"..."
"..."
We stared at the sunken wreckage in stunned silence, our minds racing to figure out how we were actually supposed to reach that island.