It was fortunate that when Rei used the Paired Orb to contact Grimm, the other side responded immediately.
"Rei? What is it? I happen to be free at the moment, so there's no issue, but."
Grimm's face in the Paired Orb was still a skull as always, yet somehow, from the way he spoke, it seemed as though he was smiling.
To Grimm, Rei was the successor to the Zephyle he so admired—and one who possessed the ability to match that title. More than anything, Rei had never shown fear or hostility upon seeing him as an Undead. Because of that, Grimm harbored feelings for him not unlike those a grandfather might have for a grandson.
Since this was a call from Rei, there was no reason he wouldn't be pleased.
"There's something I don't quite understand. It seemed like it fell within your area of expertise, so I figured I'd ask you about it."
"Mine? In that case, is it about the Undead?"
"Not quite. I found what looks like a magic circle and an altar related to Necromancy... in a golem workshop. And there's a rumor that this workshop uses humans as materials to make golems."
Honestly, the very fact that such a rumor existed and that a magic circle apparently tied to Necromancy was here gave Rei nothing but bad premonitions.
At the same time, it was true that his expectations had veered in a worse direction than he'd initially feared.
He had originally assumed they were rendering people—bandits—helpless through some means, then dissecting them and using their bodies as golem material.
But if Necromancy was involved, the picture shifted slightly.
If they were simply using human bodies as raw material, there would be no need for a Necromancy magic circle.
(As a possibility... since they're using human bodies as material, maybe they're preventing decomposition?)
Naturally, when using human body parts as golem components, some form of treatment would be necessary to prevent eventual decay. Rei had initially assumed they were applying an alchemical treatment to forestall that, but the possibility that the method itself was Necromancy couldn't be ruled out.
Why alchemists would resort to Necromancy rather than Alchemy—their true forte—was beyond him, though.
"Hmm? Necromancy and golems, you say. That is a combination I have heard of before."
"Eh? Really?"
Rei had used the Paired Orb thinking that if it involved Necromancy, asking Grimm—an Undead himself—might yield some answers. He never expected to stumble onto such a promising lead so quickly.
"Indeed. However... where did those people acquire this technology? This was developed long after the era in which I lived, but even so, it is a technology from quite a long time ago, you understand?"
"That's..."
Nothing but bad premonitions.
As if reading the sentiment written on Rei's face, Grimm continued from the other side of the Paired Orb.
"That was strictly on the assumption that my conjecture is correct. There is every possibility it is something else entirely, so rest easy."
Whether it was wise to trust Grimm's words, Rei honestly wasn't sure. Still, given the current situation, it was an undeniable fact that he should prepare for the worst.
"So what would it look like specifically?"
Deciding he should at least hear that much, Rei pressed Grimm.
Seeing Rei's demeanor, Grimm hesitated briefly over whether to speak... before eventually opening his mouth.
"The fact that Necromancy is being used means it is related to the Undead. Now then, what exactly are the Undead?"
"What exactly...? Simply put, they're moving corpses—beings that ought to be dead but are moving for some reason. Something like that, right? Zombies and Skeletons, in plain terms."
"Indeed. That is the common understanding. However, such Undead possess no will of their own. In that sense, you could say it is not particularly relevant to the matter at hand."
"Meaning?"
"Most likely, that magic circle and altar are something that pertains to human souls."
"...Souls?"
The word that slipped from Grimm's mouth was enough to both surprise and convince Rei.
At the same time, it overturned his assumption that human bodies were being used as material.
"Not human corpses, but souls were being used as golem material?"
"By my conjecture, that would be the case. And given the state of that altar, it would not be the golems themselves, but rather a separate component... yes, something like a core, in which souls were being housed."
The words from Grimm's mouth were exactly what Rei had anticipated.
Listening to them, Rei recalled the battle with Ilunara's golems right after entering this building. When Rei had been about to strike one of the golems, it had seemed to reflexively raise its arm.
That movement had looked less like a programmed golem response and more like a human reflexively shielding their body when attacked.
Whether that was actually the truth, Rei couldn't say for certain.
But if he was told a soul dwelled within the golem's core, it was something he could accept.
(Did Ilunara and the others know about this? No, considering how they reacted, that's out of the question. They showed strong revulsion at the very idea of using humans as materials. In that case, the likely explanation would be... right, they did say the cores they used for golem-making were handed to them by the mainstream faction.)
Without knowing that human souls were sealed inside the cores, they had been making golems as usual.
Thinking of it that way, Rei could accept it.
"Are both the magic circle and the altar necessary to seal souls into golem cores like that?"
"You are correct, Rei, but if asked which is more important, it would undoubtedly be the altar. Even through the Paired Orb, that altar is visibly radiating power. You can sense that too, can you not?"
"If you ask me whether I can sense it or not—yes, I can. When I entered this section, the one my companions aren't permitted into, I definitely felt something. And that feeling grew stronger the moment I stepped into this room."
"Hmm, it seems there is no mistake, then. So tell me—between the altar and the magic circle, which gives you a stronger sense of incongruity? The 'something' you described, that is."
At those words, Rei looked once more at both the magic circle and the altar.
Both emanated something... unpleasant. But looking at them again like this, the answer was obvious at a glance.
"The altar. I do feel something from the magic circle too, but what I sense from the altar is definitely stronger."
"I see. Your senses are sharp, Rei. Given that, there is no doubt. If so, the altar is indeed of greater importance."
"Is it really all right to decide that so easily?"
For Rei, he was simply feeling that way naturally. Whether it truly meant what Grimm claimed... that was still difficult to accept at face value.
Seeing Rei's bewilderment, Grimm nodded from the other side of the Paired Orb.
"Considering your body, Rei, that intuition of yours is very likely correct. Given that, your judgment is not mistaken. Although... the one to make the final decision is, ultimately, you."
"...Understood."
"Now then, is that all the business you had? I shall return to observing the other world."
Hearing mention of observing the other world, what came to Rei's mind was naturally the Centaurs.
There had been talk of eventually conducting trade between that world and Gilm, but Rei had no idea where things stood on that front now. Fundamentally, all Rei had done was inform Daskar about the situation over there.
What had happened since, while he was somewhat curious, he had more pressing matters to prioritize right now.
"Understood. Until next time, then."
"Indeed. Contact me again should anything come up."
With those words, the Paired Orb went dark.
Grimm was, by all rights, an extraordinarily powerful Undead. Yet the way he interacted with Rei was like a grandfather doting on his grandson.
Undoubtedly, Rei's connection to the Zephyle Clan played a large part in that. But it was equally proof that he and Grimm got along well.
In the silence-filled room, Rei surveyed his surroundings once more.
Strangely, the something he had felt from the magic circle and the altar before speaking with Grimm wasn't as strong anymore. It wasn't that the sensation had vanished entirely, but it had clearly weakened.
Rei couldn't explain it, but he figured that because he now understood the nature of what had been unknown to him, it had lost some of its potency.
The unknown is frightening in and of itself.
But by the same token, once something was no longer unknown, it was no longer frightening.
That was why, even now, while he still felt something, it had probably grown weaker.
(Even if I'm going to destroy the altar, I should hear Ilunara's opinion first.)
He understood the logic behind the altar now. But having reached that understanding, he judged it would be better to consult with Ilunara before disposing of it. He turned toward the hole he had made in the wall.
"Ilunara, got a moment? I've got a general picture of what's going on."
"You've figured out the situation?"
Ilunara had known Rei was going to consult his master. He'd been surprised that Rei possessed something as rare as a Paired Orb, but even so, he probably hadn't expected Rei to learn the effects of the magic circle and altar simply from a consultation.
"Yeah, my master is very knowledgeable."
Rei told him with a note of pride, facing Ilunara's astonished expression.
Looking at that face, it was clear Rei wasn't lying. Which meant he really had grasped what was happening in this place.
"Then what exactly is going on here?"
"We were fundamentally mistaken. We thought they were using humans as materials to make golems, but that's not what's actually happening. Of course, in a sense they are using humans as materials—but the method is completely different from what we expected."
"Specifically?"
"That magic circle and altar. According to what my master could see through the Paired Orb, the altar has the effect of extracting the soul from a person placed on one side of it."
"Extracting the soul?"
"That's right. And the extracted soul is then used for the core placed on the other side. Whether that means confining the soul inside the core, or something more like melting it in—I don't know the specifics. But either way, that's how the soul ends up in the core. And a golem built with a soul-imbued core..."
"...would possess higher performance than a standard golem."
Trembling slightly, Ilunara nonetheless voiced the worst possible conclusion for himself and the Dolan Workshop.
That was the reason the Dolan Workshop's golems outperformed all others.
And in the next moment, he drew a sharp breath as realization struck.
"The golems we were using... could it be..."
"Given that you received your cores from the mainstream faction, most likely."
"But! The golems we created never matched the performance of the ones the mainstream faction built!"
That's why it must be different, Ilunara insisted.
In response, Rei thought for a moment before speaking.
"I don't know the finer details myself. But based on what you've told me—when the mainstream faction handed cores over to you, do you think they'd give you the high-performance ones?"
"That's..."
"If they're going to these lengths to enhance core performance, then the cores given to you were probably low-grade ones, or perhaps even failed products. Something along those lines."
Rei's words must have struck a chord.
Ilunara's expression darkened, and he fell silent.
On the level of circumstantial evidence, he had no choice but to concede that Rei was probably right.
That said, even having accepted it, there was nothing he could do about the situation right now.
The notion that they weren't using human bodies as material, but rather human souls—that was something Ilunara had never seen coming.
"What... am I supposed to do about this...?"
Still looking stricken, Ilunara managed to mutter only that much.
And the proposal Rei offered to him was—
"For now, leaving this altar as it is would be dangerous in all sorts of ways. Given that, wouldn't it be better to destroy it?"
That was the suggestion he put forward.