"Hoh, so this is... the place, is it."
The center of the Treant Forest. Upon arriving, Grimm murmured thoughtfully.
From Rei's perspective, Grimm was someone who knew all sorts of things that Rei himself did not.
That was exactly why he never expected Grimm to utter such words upon merely arriving at the center of the forest.
"Are you sensing something?"
"Hmm. Just as I suspected, there is no doubt that something here is involved. ...What will you do? Shall I go with you?"
Rei hesitated at Grimm's words.
If Grimm were with him, he felt they could handle the source of this teleportation no matter what it was.
But at the same time, it was also true that he felt solving this whole matter on his own without consulting anyone might be a problem.
"For now, I just want to see it for myself. I'll decide what to do about it after that. ...If it turns out to be something truly beyond my ability to handle, could I ask you, Grimm?"
"I don't mind, but in that case, I will take that something as my reward, you know?"
There was no doubt that Grimm thought of Rei as something akin to a grandson, but that did not mean he indulged him unconditionally.
If he were the one to resolve this matter, he would certainly take the cause of the incident as his reward, just as he said.
For Grimm, who excelled at Teleportation Magic, something capable of performing inter-world teleportation was fascinating enough to capture his interest.
Even with the Eyeball materials he was currently researching, he was studying how to deal with the fact that they existed in the dimensional rift.
The dimensional rift and teleportation to another world.
These two were similar in appearance yet fundamentally different.
However, since they were similar, it would not be strange for them to share properties, and it was only natural for him to be interested in both.
"Ah... that's a bit of a problem. I can't just handle this whole affair on my own. In that case, I'll inform Lord Daskar by tomorrow and just observe the situation for today. Is that acceptable?"
"If Rei says that is fine, then it is fine with me."
At Grimm's words, Rei felt relieved.
Considering Grimm's personality, there was a possibility—only a very slight one, but a possibility nonetheless—that he might solve this entire series of events on his own and then take the person or object responsible as his reward. It wouldn't have been strange for him to think that way.
"Sorry about that, and thanks. ...Well then, shall we go? Do you know exactly where and how to proceed?"
"Hmm..."
Grimm muttered a single word in response to Rei's question and plunged the ferrule of his staff into the ground, just as he had when he found this location earlier.
But this time, unlike before, even Rei could not sense any magical power.
Given the previous incident, it wouldn't have been strange for him to sense something, but...
Thinking this, Rei turned his gaze toward Grimm.
However, despite Rei's gaze, Grimm showed no particular concern and concentrated on something...
"It is this way."
Perhaps sensing something, he said only that and began walking.
No, to be precise, he was not walking on the ground but floating slightly above it, and a more accurate description would be that he was gliding just above the surface.
When they had traveled here riding on Set, Grimm had also been flying through the sky, so Rei hadn't paid it much attention, but gliding just above the ground was different from flying through the air.
From Rei's perspective, the overwhelming impression was that it was quite an unusual method of movement.
In any case, he decided that following Grimm took priority and began walking with Set.
Perhaps because Grimm knew Rei was following behind, his speed of movement through the air was not particularly fast.
It was a pace at which one would not fall behind by walking slightly faster.
Thus, they moved from the place where they had previously fought what could be called the boss of the Treant Forest. After several minutes of walking...
Grimm suddenly stopped.
Rei watched with keen interest, wondering what he was doing. Whether Rei's gaze tickled Grimm's pride or not, he pointed the other end of his staff—not the ferrule—toward the ground with a somewhat grand motion.
Rei couldn't help but wonder what Grimm was doing...
Thump.
A pulse, as if space itself were vibrating, spread through the surroundings.
Just as when Grimm had searched with his staff a second time, he was not doing anything that would allow Rei to sense magical power.
He wasn't, and yet, despite not possessing the ability to sense magic, Rei could feel the magical power rising from Grimm's body.
This was nothing special—it was simply that the magical power released by Grimm was so dense that even someone like Rei, whose ability to sense magic was extremely low, could feel it.
In terms of increasing mana density, Rei's ultimate technique, the Flame Emperor's Crimson Armor, was somewhat similar, but what Grimm was doing was subtly different from concentrating mana when using the Flame Emperor's Crimson Armor.
"Similar yet different" was the most fitting expression in this case.
(This is...)
Watching Grimm, Rei was astonished inwardly.
Keeping that astonishment from showing on his face or in his words was the best Rei could manage in this situation.
Set, too, was watching Grimm while preparing to grab Rei and flee at a moment's notice if anything happened.
But Grimm, completely oblivious to the person and creature behind him, condensed his magical power... and suddenly, a heavy, rumbling sound—zu zu zu zu—like something massive shifting, could be heard.
Rei grew alert at the sound, but it was immediately apparent what was making it.
After all, the ground Grimm was pointing his staff toward was peeling upward.
...Yes. "Peeling upward" was the most fitting description for the sight before them.
The sight of the ground peeling up on its own was bizarre even in the eyes of Rei, who had used the Terrain Manipulation skill countless times.
Rei and Set stared intently at the spectacle.
The ground peeled up completely, and before they knew it, a hole... a path leading underground existed where the earth had been torn open.
"This is..."
The words that slipped from Rei's mouth were exactly the same as those he had been unable to say seconds ago.
But from Rei's perspective, that was just how extraordinary what Grimm had done was.
He hadn't confirmed it carefully, but it seemed to Rei that Grimm had forcibly opened a hole in the ground with sheer magical power.
And without even chanting.
To be precise, he hadn't used magic itself but had merely moved his magical power to produce this result.
"Foh foh foh. Did I surprise you? This is one of the things I obtained from studying that Eyeball monster."
"...Studying that Eyeball—what about it led to this?"
As far as Rei knew, the Eyeball's abilities consisted of freely traveling between the dimensional rift and this world, unleashing what seemed like an infinite number of tentacles, and creating monsters by preparing sacrifices and using their souls.
While its offensive capabilities were undeniably significant, in terms of special abilities, it was those three.
Among those three, there was nothing that involved increasing mana density and using that raw mana to exert physical influence on a target.
(If I had to stretch for one... did he figure out the ability that creates monsters using sacrifices, and instead of creating monsters, he altered mana density? No, that's a bit of a stretch.)
Or perhaps he had created a Magic Item that could generate infinite magical power from the infinitely growing tentacles? He thought that too, but that also seemed like a stretch.
"Unfortunately, I cannot teach this to you, Rei. In the first place, this is a byproduct of my original objective."
"A byproduct... something this outrageous?"
If he had simply dug up and uncovered a pre-existing hidden passage, Rei might have been able to... well, with considerable force of will, accept it.
But from what Rei could see, what Grimm had done was excavate bare earth where nothing had been before and forcibly create a passage to the desired location—the place where the cause of the recent teleportations resided.
Being told that a power capable of such tremendous feats was merely a byproduct was not something Rei could readily accept.
He couldn't accept it... and yet, the fact that he somehow found himself believing it when Grimm said so was also true.
"Hmm."
Grimm said simply, as if it were the most natural thing in the world.
Looking at Grimm's demeanor, it was impossible to think he was lying or exaggerating.
"Ah... well, I understand the gist of it for now. I get that even if I asked you about it here, I wouldn't be able to comprehend it. So, the problem is this passage..."
Having forced himself to accept it, Rei turned his gaze to Set.
The passage Grimm had created posed no issue for Rei or Grimm to travel through, but it would be extremely difficult for Set to pass through.
"I could get in if I used Size Change... but I don't know how far it goes."
"Grru..."
Size Change was a skill that could shrink Set's body, but the problem was its duration.
Since it could not maintain that size indefinitely, if the effect wore off midway through the passage, things would become quite troublesome.
"In that case, I'll need you to stay here after all, Set."
"Grru..."
At Rei's words, Set purred disappointedly.
Even so, the fact that he didn't try to force his way in was likely because he thought being selfish might cause trouble for Rei.
In fact, if Set returned to his original size midway through the tunnel and blocked the path, Grimm would have to use his magical power to create a new passage.
Or they would have to widen the passage to a size Set could pass through.
Rei couldn't help but think: Then shouldn't he have just made the passage large enough for Set from the start?
"Sorry, Set. When I get back, I might need you to fly me to Gilm right away. ...Or maybe it would be better to wait until tomorrow morning?"
If there truly—and since Grimm had been the one to bring it up, Rei didn't doubt it—was something important regarding teleportation from another world ahead, then informing Daskar as soon as possible was definitely the right move.
But it was already night.
At this hour, it went without saying that they could not enter Gilm.
...If it were Set, they could force their way in from the sky, but doing something like that would cause all sorts of trouble afterward.
That said, the teleportation matter was not something that concerned Gilm alone; even the nation was involved.
Considering that, it was also certain that informing them as early as possible was the right choice.
"In any case, I'm not sure if it'll be tonight or tomorrow morning, but I'll need you to go to Gilm, so be prepared for that."
"Grrururu."
Set, purring as if to say he understood, lay down beside the passage leading underground.
So that no one would follow Rei and the others.
With Rei and Grimm present, there was no doubt that any ordinary attacker would be powerless against them.
He knew that, but all Set could do right now was that much.
"Thanks."
Rei understood Set's feelings, so he spoke a brief word of gratitude.
In response, Set lightly wagged his tail.
(He's probably trying to say he wants me to come back quickly, or something like that.)
Understanding the meaning behind Set's actions, Rei turned his gaze to Grimm.
"Well then, shall we go? ...I don't think I need to ask you, Grimm, but you're fine with exploring places like this, right?"
"Of course. Have you forgotten where it was that I first met you, Rei?"
Now that he mentioned it, Rei could only nod honestly.
After all, the first time Rei had met Grimm was in the Dungeon where the Altar of Inheritance had been located.
"Ah, come to think of it, you're right. Yeah. And even after that, you'd been using various Dungeons as your bases, hadn't you? Then I guess there was no need to worry at all."
"Hmm. Therefore, you need not worry about such things. ...Now then, there is no point in standing here talking forever. Shall we go?"
"Got it. Set, I'm leaving this place to you."
"Grru!"
At Rei's words, Set let out a cry, and to Rei, it sounded as if he were saying, Leave this place to me and go on ahead!
(No, surely not.)
He discarded the thought and shook his head.
In the current situation, there was no need to go out of his way to think such a thing.
It wasn't as though some kind of monster was attacking them, after all.
With that, Rei stepped into the passage leading underground together with Grimm.