The man called an intruder by Rei tilted his head, looking as if he didn't understand at first.
Despite being woken by a slap, he still wasn't fully alert.
He stared at Rei intently... and eventually grasped what sort of situation he was in, his mouth opening and closing repeatedly.
"I... i-intruders!? Why!? Why are intruders all the way in here!?"
"You're asking me why? In my case, I just came in the normal way."
Rei said that casually, but in reality, he had fought his way through the gatekeepers guarding the entrance to get here—hardly something that could be described as "the normal way."
"N-normal, you say..."
"That's far enough."
The man tried to say more, but Rei cut him off.
He hadn't done anything physical.
He had simply said "that's far enough," yet... the researcher found himself unable to utter another word.
If the man had been an adventurer who had weathered countless violent clashes rather than a researcher, he would have recognized that what Rei had just released was pure killing intent.
Unfortunately, while the man belonged to the dark organization Jaya, he was, in the end, nothing more than a researcher.
That was precisely why he had no idea what Rei had done to him—and yet he found himself completely unable to speak further.
"We're intruders. In other words, we want information about this place. You understand that, right?"
The force behind Rei's question made it feel as though a Giant stood right before him... no, even compared to the Giants the man knew, Rei's presence was overwhelmingly greater.
In terms of sheer physical size, of course, Rei was far smaller than a Giant.
At any rate, perhaps realizing that defying the person before him was the worst possible course of action, the man nodded repeatedly without another word.
Satisfied, Rei nodded back and spoke.
"Now then, the first thing I want to ask: there are Giants in this underground facility, right?"
A foundational question.
If the man had claimed there weren't, Rei would have judged him uncooperative.
But the man, who certainly appeared to be a researcher, nodded in response.
"Y-yeah. Of course I know that. It's just that I don't clearly understand exactly how they're created yet."
"...I've heard it's the effect of that Slave Collar?"
"That's certainly true. But the exact mechanism behind how a Giant is born still isn't understood."
"Huh? It's a Magic Item your people developed, isn't it? Or was it one you created by accident?"
The man Rei's party had brought as a guide was ultimately someone assigned to a role requiring physical action, so it wouldn't have been strange for him to know little about Magic Items.
But the man now standing before Rei, given the state of his room, could only be a researcher or an Alchemist.
(Could I have been mistaken?)
Just because the man looked the part didn't necessarily mean he was a true researcher or Alchemist.
There was even a slight possibility he was completely unrelated.
"I'll ask just in case—you're a researcher or Alchemist affiliated with Jaya, correct?"
"Ah, of course."
The man answered without hesitation.
For a brief moment—a very brief moment—Rei wondered if the man had simply been left in charge of tidying the room and had fallen asleep from exhaustion. But that thought was immediately dispelled by the man's next words.
"...Then let me ask again. Why don't you understand the reason Giants are born from the Slave Collar's effect?"
"Because that Slave Collar, and the Black Crystal it originates from, aren't things we made. They were given to us."
The man answered matter-of-factly, without any sign of reluctance.
Rei noticed the man's words contained information his party didn't know and voiced it aloud.
"Black Crystal?"
"Yeah. What you people call a Slave Collar—strictly speaking, that's not what it is. Though it does have similar effects."
What came out of the man's mouth was entirely unexpected.
Yet at the same time, it made sense.
The Slave Collars used in Mejougo had always been strange in various ways.
A normal Slave Collar could compel the wearer to act against their will, but it couldn't alter their very will itself.
The Slave Collars used in Mejougo, however, completely rewrote the wearer's will.
So thoroughly that even a woman normally fastidious about relations between men and women would willingly choose to work as a prostitute... just like that.
And according to Rei's prediction—more like a half-conviction—that Slave Collar was supposed to be the condition for birthing Giants.
"Making them birth Giants is one of those effects too?"
"That's right. But strictly speaking, simply wearing the Slave Collar alone doesn't allow someone to give birth to a Giant. Only when someone wearing a Slave Collar becomes pregnant here in Mejougo—where the Black Crystal exerts its magical influence—can a Giant finally be born."
A note of frustration crept into the man's voice as he said this.
"So what exactly is this Black Crystal? Is it literally a black crystal?"
"No, I don't know its exact name. We call it Black Crystal based on its appearance, but it's not actually a crystal."
The man was forcing women into prostitution and making them birth Giants, yet he showed not the slightest sign of guilt.
At that, the mood of everyone besides Rei rapidly soured—but the man remained completely oblivious.
Sensing that letting this continue would lead to trouble, Rei steered the conversation back to the main subject.
"...I should have asked this first. That Black Crystal and the Slave Collar—they aren't things you people created, then?"
"That's right. I only research the Black Crystal."
"Then who created it? Or where was it discovered?"
If the Black Crystal was simply a type of special magical ore excavated from somewhere, there wouldn't be much cause for concern.
But if someone had actually created it... that would be dangerous in every sense of the word.
Because if it had been made once, there was a possibility it could be made again.
Rei asked with that thought in mind, but the man simply shook his head.
"I don't know. Originally, I was in another country researching magical minerals—famous ones like Flame Ore and the like. I was brought here specifically to research the Black Crystal."
"...Brought here? Were you forced to conduct research here against your will?"
Hearing this, Rei wondered if the man before him had been abducted just like the prostitutes and was being forced to do research. But the man shook his head once more.
"When I was first brought here, of course it was against my will. But the reason I'm still here researching is simply because I want to. No matter how much I study it, I can barely figure out anything about that Black Crystal."
The man paused, then shook his head with exaggerated disbelief.
"That Black Crystal! It's not even a Magic Item, yet it creates a field that exerts that much influence—why? I can't stand it, I'm so curious! From its appearance alone, there's no sign of any special craftsmanship. And yet..."
The man continued rattling off one question about the Black Crystal after another.
From his demeanor, it was impossible to see him as someone being forced to research against his will, as he had claimed.
It was obvious to anyone that he was here of his own volition.
(Being kidnapped, then sympathizing with the kidnapper and growing close to them during captivity... what was that called again? Stockholm Syndrome? No, it couldn't possibly be that.)
Rei recalled the concept from his knowledge of Japan, but the person before him didn't seem to fit that pattern.
Of course, Rei had never actually seen someone with Stockholm Syndrome firsthand. He had only encountered the concept through anime, manga, novels, movies, and dramas that used it as a theme.
So even if the man truly did have Stockholm Syndrome, Rei wouldn't have been able to say for certain.
Then again, even if it was Stockholm Syndrome, it wouldn't change the fact that this man had been cooperating with Jaya—nor would it change the fact that he was now gleefully explaining the Black Crystal to Rei.
At that point, Rei understood perfectly: the man had always been this kind of person, the type who believed any number of people could be sacrificed for the sake of research.
The man himself might not realize how many he had sacrificed, but even if he wasn't directly killing anyone, cooperating with Jaya's research inevitably produced exactly those results.
"I see. I understand the situation. In other words... you're our enemy."
"Hardly! There's no way that's true!? I'm nothing but a researcher. Whoever you people are, it has nothing to do with me. Though I suppose I should thank you for waking me up. My research is getting rather busy right now. If my hypothesis is correct..."
"That's far enough."
Interrupted mid-sentence, the man shot Rei a dissatisfied look, clearly wanting to say more.
But Rei, meeting that gaze, silently gestured for the man to look at Elena and the others standing nearby.
What the man saw was Elena and the others, wearing expressions of unmistakable displeasure.
Their refined features only made it more apparent just how much irritation was simmering behind the gazes fixed on him.
Faced with stares that could only be described as absolute zero, even the man couldn't bring himself to continue bragging about his research.
"U-um, why are you all looking at me like that? I don't think I've done anything particularly wrong..."
The man genuinely could not understand why he was being subjected to such gazes.
He did, however, seem to grasp that if things continued like this, the situation would go from bad to worse.
With a bewildered expression, he turned a pleading look on Rei, silently begging for help.
Rei's response was to calm Elena and the others down for the time being.
Not out of concern for the man's well-being, mind you—but because if Elena and the others acted on their emotions and harmed him, Rei would lose his only source of information.
...He stopped them because losing the ability to extract information from the man would be a problem, so it wasn't entirely wrong to say he had the man's safety in mind.
"Elena, Marina, Vihera, that's enough."
That was why he told the three of them to rein in their anger.
But Rei made one critical mistake in that moment: he told the three radiating intense fury to calm down, yet said nothing about the one person standing behind them. As a result...
"Uwah! Ow! It hurts!"
As if seizing the opening created while Rei was busy calming the other three, a single Long Needle flew through the air.
Rei had been focused on settling Elena and the others, and naturally, he had also kept watch to ensure the man—his information source—didn't try to flee.
But... no, perhaps precisely because of that focus, he had completely forgotten about the last person in the room: Byune.
The man screamed, staring at the Long Needle embedded in his arm.
Whether he was actually in pain or simply shrieking at the sight of it, Rei couldn't say.
What he did understand was this: even though she never showed it on her face, Byune had been every bit as furious as the other three.
Byune, while still young enough to be called a girl, was a grown woman.
As such, she naturally harbored an intense disgust toward what was being done in Mejougo.
The reason Rei hadn't noticed was simple—Byune never expressed her emotions through her face.
That was why he had failed to grasp just how furious she truly was.
...Or perhaps he still saw Byune as a child, and the thought simply hadn't crossed his mind.
At any rate, the ones Rei had stopped were only Elena, Marina, and Vihera.
Realizing she hadn't been told to stand down, Byune seized the opportunity and let fly her signature weapon—the Long Needle—at the man.
Even so, the fact that she didn't draw Hakumo, her dagger forged from Silver Lion materials, suggested she hadn't completely lost herself to rage.
The man was lucky to still be alive. But a man screaming in pain was hardly about to feel grateful for the distinction.