After grasping the effects of Underground Transfer Slash, Rei and Set immediately left the area.
This wasn't about the smell of blood or anything of the sort. Right now, heading toward the outskirts of the Forest of Magic as quickly as possible was about ensuring they wouldn't fail the Promotion Exam by still being inside when the date changed, should the worst happen.
(Getting a Magic Stone from that hair Fish for Death Scythe too was a good catch. ...The problem is, it'd be troublesome if any more showed up.)
The Fish covered in hair all over its body was an eerie, deeply discomforting presence to Rei—and to Set, for that matter.
Given that, it was only natural to hope he'd never have to fight such an enemy again if he could help it.
(What's left is a Hermit Crab... and not just a normal one, but a Rare Species Hermit Crab's Magic Stone. That's what I'd want, but I wonder how that would go.)
A Rare Species was called that precisely because encountering one was exceedingly rare.
That being the case, whether they could run into a Rare Species of the same monster again came down to luck.
And it would require considerable luck at that.
Because of that, Rei found it highly regrettable, but he was able to accept it honestly.
(The first Fish that showed up just had to drag the Rare Species underground of all things. At the very least, it should have been a normal Hermit Crab.)
He could accept it, but having a Rare Species stolen right before his eyes naturally didn't sit well, and he made no effort to hide his dissatisfaction.
He scanned the surroundings, wondering whether any new monsters might attack, when...
"Fog? At this hour?"
Seeing fog drifting through the area, Rei was surprised.
As far as Rei knew, fog was something that formed near bodies of water like lakes in the early morning.
Granted, if it involved a lake, then given the situation with the Barrier, the geographical conditions might have been met.
But the current time was evening.
Moreover, a fair amount of time had passed since they left the Barrier, so the surroundings were already growing dim.
The reason Rei and Set were traveling along the riverbank—a place where trees and similar vegetation grew sparsely—was precisely why the faint light of the setting sun still filtered through. But if they left the river and entered the Forest of Magic proper, the branches of the surrounding trees would block the light, and it wouldn't be unusual for it to be dark.
Fog appearing at such a time struck Rei as odd.
Granted, fog forming in the morning was only what Rei knew from his own knowledge, and there was ample possibility it could occur due to some other factor as well.
The fog drifting around them hadn't grown that thick yet, so Rei and Set had been advancing without paying it much mind... but eventually, as they pressed on, the fog grew denser.
When thick fog began to fill the area around them, so heavy it felt like they were walking through white gas, Rei concluded this was no ordinary natural phenomenon.
No matter how one looked at it, the fog had thickened far too quickly.
"A monster? ...Set, hold up for a second."
"Gruu."
At Rei's words, Set halted.
It was precisely because it was Set that it could advance normally through thick fog where one couldn't see even a few dozen centimeters ahead, without stumbling.
If it had been some ordinary monster or animal instead of Set, it definitely wouldn't have been able to move forward.
It might have crashed into the trees of the Forest of Magic, caught a foot on a rock and tripped, or fallen into the river.
Any of those outcomes could directly lead to death depending on the circumstances, and it wouldn't be unusual.
The fact that Set could advance through such conditions without issue showed it truly possessed extraordinarily sharp five senses and a Sixth Sense.
"Set, do you think this is some monster's doing after all?"
"Gruu? Grururururu."
In response to Rei's question, Set hesitated briefly before purring as if to say that was probably the case.
Seeing Set's reaction, Rei was convinced that this was indeed an enemy's doing.
Being convinced was fine, but... the real problem was how to deal with this fog.
How far the fog extended was something even Rei couldn't determine.
But based on how far they'd already come, he could tell that a fairly wide area was blanketed in it.
In other words, the direction they were currently heading was likely the center of the fog... its source.
(That said, the problem is how far we have to keep going through this thick fog.)
When Rei looked around, it was hard to tell how far the white fog spread or which direction held denser fog.
"Set, I'm relying on you from here. Alright?"
"Gruu!"
At Rei's words, Set purred as if to say, "Leave it to me!"
Even if it was impossible for Rei, Set could manage somehow.
Rising to Rei's expectations, Set pressed forward.
Rei was riding on Set's back, so there was no particular need for him to move on his own, but the direction Set was heading was undoubtedly enveloped in what could only be called thick fog.
(The problem is this fog... the fact that it's ordinary fog with no special abilities or tricks whatsoever.)
Rei cautiously extended a hand, but the hand that touched the fog felt nothing out of the ordinary.
For instance, it could have been acidic fog that damaged whatever it touched, or it could have drained stamina or magical power on contact... it wouldn't have been strange for such abilities to exist, but what was spreading was truly nothing more than ordinary fog.
(Fog, huh. ...Could this be a Vampire's doing, by any chance?)
The Dark World Tree that had stood in this Forest of Magic.
Rei had fought the Vampire raising it, and had safely defeated that opponent.
The body that had turned to ash and the Magic Stone were stored inside the Misty Ring, so he didn't think that particular Vampire had been revived through some means—but there was a possibility that a different Vampire, separate from the one Rei had killed, had come.
Thinking about it normally, a High-Rank Monster like a Vampire wouldn't show itself so readily, but this was, after all, the Forest of Magic.
It wouldn't be strange for High-Rank Monsters to appear one after another, and Rei had actually defeated several over the course of two nights and three days.
And with the sun already setting, it was also a time of day when it wouldn't be unusual for a Vampire to appear.
"Set, do you think it's a Vampire?"
"Gruu? ...Grururu."
Set considered Rei's question for a moment, then shook its head in denial.
"Not a Vampire?"
"Gruu!"
Set purred with inexplicable confidence.
What reason it had for that judgment was something even Rei couldn't fathom.
He couldn't fathom it, but considering Set's abilities, he could imagine there was probably some reason only Set could perceive.
What exactly that was, Rei couldn't know.
Even so, since Set was that assertive, Rei's expression shifted to one of understanding.
...He had fully grasped during last night's battle that a Vampire's abilities were extraordinarily diverse.
Because of that, not having to fight a Vampire in this situation was something Rei was grateful for.
In truth, since he only had one Vampire Magic Stone, he honestly wanted two—one for Set and one for Death Scythe.
But right now, there wasn't much time.
If they remained in the Forest of Magic past the date change, it would mean failing the Promotion Exam.
That was precisely why he didn't want to fight a Vampire right now.
(That said, that ultimately brings up the question of what kind of monster is creating this fog. If it's producing fog over such a wide area, it's obviously not a Low-Rank Monster.)
The surrounding fog had already grown so thick that one couldn't see even a few centimeters ahead.
To Rei, it felt less like he was advancing through fog and more like he was wading through a milky liquid.
"Grurururururu!"
And so, how far had they walked through the fog... just as Rei was losing track, Set suddenly let out a sharp cry.
"Finally."
For Rei, hearing Set's cry, that was his honest thought.
That said, in such dense fog, properly confirming the enemy's appearance was impossible.
All Rei could do right now was ready Death Scythe and the Twilight Spear, and counterattack immediately if the enemy struck.
"Uooooooooooouuuuuu."
That voice rang out from within the fog.
Reacting to the sound, Rei swung Death Scythe.
But the blade met no resistance whatsoever.
It felt less like he had cleaved through an enemy and more like he had merely slashed through empty space where the fog drifted.
(Considering the timing of the voice, it shouldn't have been strange for the blow to connect. If that's the case, the enemy is definitely pulling some kind of trick. ...The problem is, I have no idea what that trick is.)
The Death Scythe Rei had just swung had undeniably been timed correctly for the attack.
If that was the case, he needed to consider a different approach.
(Cutting fog is difficult in the first place. No, but that applies to ordinary fog. Since it's clear that this fog is produced by some kind of monster, magical power is definitely being used. If that's the case, can Death Scythe or the Twilight Spear cut through it?)
With that in mind, Rei channeled magical power into Death Scythe and swung.
Even without deliberately aiming, Rei's entire surroundings were shrouded in fog.
It was no exaggeration to say he was standing in a sea of fog.
Yet the moment Rei swung Death Scythe, the white fog vanished cleanly.
The fog disappeared as if erased by an eraser rubbing out a wrong answer, and the landscape of the Forest of Magic came into view.
However... being able to see the Forest of Magic lasted for less than a second.
The area where Death Scythe had cleared the fog was immediately swallowed up as the surrounding fog rushed back in.
"So I can do something about it... but it's a nuisance."
It was now clear from Death Scythe's attack that the fog was composed of magical power.
But at the same time, it was equally clear that eliminating a small amount of fog with Death Scythe was pointless.
Compared to the area Rei could clear at once, the enemy's speed in regenerating the fog was extremely fast.
Rei likened it to a game where an enemy with automatic HP recovery was dealt damage lower than its recovery rate.
That said, even as he thought about such things, another question surfaced.
(Why isn't the monster attacking? No, it definitely approached earlier, that much is certain.)
While that strange cry echoed through the area, the enemy never actually launched an attack.
Rei found that puzzling, and once again wondered if there was something more to this fog.
But when he examined the fog again, just as before, it didn't seem to inflict any particular damage.
"Set, what do you think the monster producing this fog is trying to accomplish? This fog doesn't have any special effect that I can tell. If that's the case, I can only think it's simply trying to seal off our vision..."
"Gruru."
Set purred as if agreeing with Rei's words.
Even by Set's senses, there was nothing particularly unusual about this fog.
Seeing Set's reaction, Rei felt a twinge of disappointment that even Set couldn't detect anything.
(So is it really that there's nothing at all... or is there something, but Set and I simply can't perceive it? If we were outside the Forest of Magic, I could confidently say it's the former.)
In this Forest of Magic, S-Rank Monsters like the Crystal Dragon also existed.
Because of that, it wouldn't be strange for there to be a monster capable of imbuing the fog with some ability that Rei and Set couldn't perceive.
"Set, use Magic Eye of Shock. Any target will do."
"Gruu? ...Grururu."
Following Rei's instruction, Set activated Magic Eye of Shock.
While its power was modest, it was a Skill second to none when it came to activation speed.
The Skill triggered, and a portion of the fog some distance away was eliminated.
"Magic Eye of Shock can clear the fog too. ...If that's the case, it's safe to assume that no matter what kind of Skill it is, the fog will vanish as long as it lands a hit."
The power of Magic Eye of Shock was the lowest among the Skills possessed by Set and Death Scythe.
That was excluding Skills without attack power, such as Sense of Smell Enhancement.
If even such a Skill could eliminate the fog, then it was certain that any Skill with attack power could do the same.
"This looks like the key to cracking this one."
Rei murmured to himself, and began considering what he should do next.