Chapter 16

A sudden surge in magic energy across the surrounding area. With electronic devices becoming uncontrollable and the risk of large-scale accidents predicted, emergency alerts blared all at once, and at the same time an announcement relayed a message from the event staff:

“All explorers are to proceed to the launch site.”

It wasn’t only Arnie who had thought of it. The theory once dismissed as mere speculation—that dungeons seek magic and expand their scale—had persisted among modern researchers. With this abrupt rise in magical energy, they predicted that the “theory would become reality,” and prepared for the worst.

Thus, under the official authority of the Dungeon Management Center, explorers present at the venue began converging on the launch site.

“Hey! This has got to be the biggest incident since dungeons first appeared, right!? You think this affects our evaluations or something!? Is this a chance to show off!?”

“Now’s not the time for that! According to eyewitnesses, monsters appeared at the launch site! Hurry up—only explorers can deal with monsters!”

“Mm… to be honest, my wife and daughter are here at the venue today. If monsters start spilling out…”

“But the buses and cars at the venue aren’t moving right now, right? Maybe we should’ve coordinated with the police handling crowd control. I only just became an explorer—I won’t be much help in a fight.”

“What are you saying, elite? Come on, let’s go!”

Explorers who had been enjoying the festival nearby headed toward the launch site—no, toward the newly born dungeon. And before long, those who gathered there would witness it.

The moment a new dungeon was born.
The harbinger of a disaster that would be written into history textbooks.
A vast horde of monsters that could potentially devastate an urban area.

And above all—

The moment a hero of the next generation was born.

“Onee-san, I think people who look like explorers are approaching!”

“Good. Then… I’ll give them instructions to place them under my command. Akira, if anything happens, move in sync with me. Just in case, I’ve already been making preparations on my end.”

We continued fighting relentlessly, simply carving away at the massive horde to reduce their numbers.

The strategy was straightforward: my sister would restrain them, and I’d charge straight through the slowed sections. Thanks to that, the monster horde finally seemed to have learned that being at the front meant death, and they began hesitating to leave the dungeon.

Still, they were pushed from behind, forced unwillingly onto the surface one after another.

We cut them down tirelessly, but even so, we were nearing our limits.

My sister’s magic had hit its cap multiple times already; each time, she bit down on a precious mana recovery potion, and empty bottles were beginning to pile up at her feet.

“It helps that the ambient magic density is rising. The recovery potions are working at full effect.”

“But at this rate, we’ll be ground down. The environment is getting worse.”

What made things especially troublesome was the fact that monsters killed on the surface are not absorbed by the dungeon.

Normally, when monsters die, they dissolve into magical energy and are absorbed back into the dungeon.

But monsters killed above ground took a long time to disappear.

It was a living hell. The exit of the massive pit had turned into a mire of blood and corpses.

The unstable footing directly led to reduced mobility—and that meant reduced extermination efficiency.

So reinforcements arriving now was honestly a huge relief.

Since my sister seemed to be issuing orders smoothly, I kept quiet and focused on filling the gaps she left, gritting my teeth and continuing to slay monsters just a little longer.

“You! You’re the one from earlier! Did you rush here after hearing the broadcast!?”

“That broadcast was issued under my instruction. At present, my master and I are already handling the situation. From this point on, you will operate under my command. Acting independently will only worsen things.”

“That’s quite a way of putting it. Are you saying we’ll just get in the way if we don’t follow you?”

“That is correct. Can you insert yourself into that situation?”

Arney, in truth, believed that reinforcements could sometimes be a hindrance.

The current balance was being maintained by the slimmest of margins. There was no guarantee that additional help would actually contribute.

She feared the increase of negative factors—poor coordination, blocking lines of attack, reduced extermination speed.

With only Akira and herself barely holding the line at full capacity, adding explorers weaker than herself would simply mean more dead weight.

“Th-That’s a mountain of corpses!”

“My master and I have held them back this far. You are to provide support for us. If extermination speed drops any further, we will be overrun.”

“H-Hey… she’s right. If we jump into the front line, we’ll just get in the swordsman’s way. Sorry—what should we do!?”

Confronted with the overwhelming gap in ability and reality itself, even the explorers who had resisted fell silent.

Taking that silence as acceptance of her command, Arney issued orders to everyone.

“First, station two people at the route connecting to the mainland, in case of any leaks. Next, if anyone here can use magic, follow my instructions and cast when ordered. Melee fighters should preferably stand by at the route. Those with magic or ranged attack capabilities will operate under my direct command. However, as the situation is still unstable, there may be cases where everyone will be required to act as decoys.”

She chose to treat them completely as pieces on a board.

In fact, Arnie knew the explorers gathered here.

While diving into dungeons daily, she had quietly assessed who might become strong, who required caution, and investigated their capabilities as thoroughly as possible.

All of it was for one reason: to never lose Akira again.

She had researched everything she could—who might become Akira’s enemy, who required vigilance. She knew it all.

“…Is that really the optimal solution, in your eyes?”

“That is the worst-case scenario. If it’s merely a monster horde, holding out until more reinforcements arrive should suffice. But a newly born dungeon has blurred boundaries and rules. What if a deep-layer boss—equivalent to a tenth-floor boss in Ginza—emerges onto the surface? At that point, the only thing you could do would be to act as decoys. I am not belittling you—this is simply the truth. No one here has reached level five yet, correct?”

The concept of level—the clearest, most absolute indicator of reality.

Indeed, among the explorers gathered here, the highest was level four. The rest were only levels two or three.

And to challenge a branching dungeon boss, at least two people at level five were required.

Everyone present understood that Arnie’s assessment was correct.

“My current level is seven. And… while I cannot explain the details, my master is someone who stands far beyond even me. If the worst happens, we will devise a strategy that keeps everyone alive. If you are to enter my command, I ask that you accept our policy in advance.”

“L-Level seven!? And her master is even higher than that…?”

“…Understood. Preparing for the worst is basic common sense for explorers. If—if in the worst case we rush for merit and lower the success rate of the plan, then the lives of the people at the venue will be put in danger. My wife and daughter mean more to me than anything else. If it comes down to it, staking my life as a decoy is nothing to me.”

“…You’ve got guts. Alright, I’ll follow you too. I came to the festival with some old friends from before I became an explorer. They’re probably still at the venue in this chaos. If you need decoys… tell me. I’ve got a bit of an unusual skill.”

The two explorers voiced their resolve in turn.

As if inspired by them, the rest nodded firmly as well.

They had understood: this was an unprecedented crisis.

And the only ones who could stop it were the explorers present at the venue.

If overwhelmingly powerful elites or famous explorer clans were here, things might be different.

But in the midst of this chaos, everyone understood that expecting outside reinforcements was unrealistic.

Rescue by helicopter or approach by ship would be hopeless in this level of magical density.

And above all, no organization even existed that anticipated a situation like the spontaneous birth of a dungeon.

“All right, let’s take our positions! I use a greatsword—if we’re forming a line between the launch site and the mainland, I’m the best fit.”

“I’ll stay there too. I’m a swordsman, but my skill causes small-scale earthquakes. I’m good at slowing enemies down.”

“That’s awesome! I’ve just got ‘Strength Enhancement,’ so all I can do is punch things. If you hold them in place, I’ll blow them away—count on me!”

Watching them discuss their fighting styles and coordination, Arney felt a spark of hope.

This might actually work.

But then—

“M-Maid-san…! Th-That! Something’s coming out—look at that!!”

“Wha—! Everyone, I’m sorry to interrupt while you’re forming plans, but… it seems we really will need you to act as decoys.”

An explorer woman pointed ahead with a trembling voice.

What had emerged from the massive pit was—

A grotesque, impossibly huge figure:
a two-headed giant, bearing a monstrous, alien form.