Rei's face registered surprise at the words that came from Marina's mouth.
Since Marina, a Dark Elf, was present, he had of course known that she had a homeland.
But he had never imagined being invited there—and the fact that a tree called the World Tree existed in her homeland caught him completely off guard.
"Except for a few rare exceptions, basically no one outside the Elf-kin is allowed into the forest... or so a book I read before said."
Still reeling from Marina's words, he reached for a sandwich filled with meat.
A sandwich using grilled meat slathered in sauce as its filling was clearly far too heavy a dish to serve as a tea snack.
Leafy vegetables were layered between the meat and bread, and in his mouth, the soft texture of the bread, the juices overflowing from the meat, the rich umami of the sauce, and the crisp bite of the fresh vegetables all blended into a seamless whole that delighted his palate.
There were also vegetable-centric sandwiches, and more unusually, ones containing dried fish that had been rehydrated and paired with sauce—all of them exceptionally delicious.
Savoring the sandwiches, Rei turned his gaze toward Marina.
Meeting Rei's eyes as he ate, Marina took a sip of black tea and nodded.
"Yes, that's not wrong. Whether Elf or Dark Elf, individual abilities are higher than those of ordinary humans, but they are overwhelmingly inferior in numbers. When that happens... you understand, don't you?"
Rei, having read about such circumstances in books, naturally knew all of this.
Elves and Dark Elves fundamentally possessed higher abilities than humans. And above all, an overwhelming number of them had well-proportioned features.
Indeed, Marina was a beauty described as peerless, and while Odoban's appeal differed from Marina's—whose allure seemed to embody feminine charm itself—her features were undoubtedly refined as well.
Because Elves and Dark Elves were few in number, their rarity was also high.
When that was the case, what would happen?
Since they could fetch a high price as slaves, slave merchants would never overlook them.
Not properly licensed slave merchants, but those known as dark, or underground, slave merchants.
Throughout history, there were by no means zero cases of nobles—blinded by the beauty of Elves—dispatching soldiers from their own territories to attack forests.
Most such forces suffered heavy casualties at the hands of Elves and retreated, but even so, it was not uncommon for Elves to be captured in the process.
As a result, a detrimental side effect emerged: many Elves and Dark Elves came to harbor prejudice against humans.
Of course, there were also quite a few like Marina and Filma, whom Rei had teamed up with during his Rank Up Exam, who bore no hostility toward humans.
In any case, the reasons Elves and Dark Elves who had been attacked by slave merchants and lords could hold their own against superior numbers were their high individual capabilities and, above all, the Barrier that covered the forests where they lived.
What generated that Barrier was the World Tree, which could be called the lifeline of the Elves and Dark Elves.
"Treating the World Tree... it's not like I'm a doctor, you know?"
Telling Marina this, Rei suddenly recalled a profession called a tree doctor that he had seen on TV back in Japan.
Tree doctors were, as the name suggested, people who treated plants—primarily trees.
But naturally, Rei couldn't possibly have the botanical knowledge necessary to work as a tree doctor.
Having lived in the countryside of Japan, he could identify things like wild vegetables, but that was hardly enough to treat a World Tree.
His parents were farmers, and he had helped out, but even then he had only done what he was told and possessed no specialized knowledge.
(If the World Tree were a wild vegetable... no, I don't even understand Elgin's wild vegetables, so that's out.)
At Rei's words, which could only be called the obvious, Marina and Odoban nodded in unison, and Marina spoke.
"Of course, what we're requesting isn't what you're imagining. Let's see, to put it simply, we want you to pour mana into the World Tree. The cause of the World Tree's weakening is apparently a lack of mana, so if we give it your mana for now, it should be fine for a while. During that time, we'd like you to do something about the cause of the illness."
"Pour mana? Will that cure the World Tree? With a name as grandiose as 'World Tree,' it must be a special kind of tree, right?"
The World Trees that appeared in games, manga, and novels when Rei was in Japan were almost always enormous trees that could be called divine.
In Rei's mind, the very term "World Tree" carried an image of a tree so tall that even looking up, you couldn't see its peak.
Hearing the weight behind Rei's words, Marina smiled radiantly and spoke.
"That's right. In the forests of the Elf-kin—Elves, Dark Elves, and High Elves—there is always one World Tree... no, to be precise, it would be more accurate to say that Elves settled in places where a World Tree stood. The Elf-kin manage the forests partly for the sake of the World Tree as well. And also..."
"Marina-sama."
Odoban murmured, cutting off Marina's words as if to interrupt.
Her voice was sharp, making it hard to believe she was the same person who had been acting so flippant just moments before.
For Odoban, Marina's words must have contained something she absolutely could not afford to miss.
Marina was about to tell Odoban that Rei and the others could be trusted, but Odoban had only met Rei and his group today—and only moments ago at that.
Given that, it was only natural that Odoban couldn't trust them as much as Marina did.
"You're right. I said a little too much. ...Anyway, our nomination request to Rei... specifically to the adventurers Rei, Vihera, and Byune, is as I stated earlier."
"Huh? Wait a minute, Marina-sama. The one pouring mana into the World Tree is Elena-san over there, right? So why is the nomination request for other people?"
"...Listen. Were you paying attention to what I was saying? And it's not Elena-san, it's Elena-sama. At least while you're here, address her properly. In any case, Elena-sama is not an adventurer. So even if we tried to make a request to her, it would be meaningless."
"Then, was this a wasted trip?"
"Hardly. If Rei is here, then in terms of mana—both quality and quantity—there's no issue even compared to having Elena-sama present."
"Huh? Huh?"
Odoban couldn't follow the conversation at all, but Marina had no intention of blaming her for it.
Even Marina, who had the ability to sense mana, couldn't detect any of Rei's formidable power when faced with him wearing the Ring of the New Moon.
"Rei, may I ask you something?"
As if to say seeing is believing, Marina turned moist eyes toward Rei.
Finding no particular reason to refuse, Rei gave her a nod in return.
"Odoban. Watch Rei closely. Alright? I won't tell you not to be surprised. But don't collapse on me."
"...Excuse me?"
She couldn't understand what was being asked of her.
Odoban turned her gaze toward both Rei and Marina.
The mana she could sense from Rei wasn't exactly small, but it wasn't particularly large either.
Compared to Elena, it was clearly less. Indeed, it was an amount of mana so small it couldn't even be compared.
Wondering what on earth this was about, yet believing Marina wouldn't say something without reason, she nonetheless fixed her gaze on Rei.
Rei, feeling Odoban's stare, saw Marina nod and quietly slipped the Ring of the New Moon from his finger.
In that instant...
"Eek!"
Odoban had judged, when she sensed Elena's mana earlier, that nothing could surprise her more—but the mana she now felt from Rei far surpassed even Elena's.
Indeed, in the opposite sense from before, it was something she felt couldn't even be compared.
Unconsciously retreating several steps, Odoban was finally brought back to her senses when Marina, seated in the desk chair, grabbed her hand.
Then, she once again took in Rei's mana.
It was like the impression of a vast blue sky spreading out endlessly in every direction. Or perhaps, though she had only ever heard of it in stories, the term "great ocean" stretching as far as the eye could see would also be a fitting description for the mana Rei possessed.
"M-Marina-sama... what is this?"
Odoban asked timidly, but Marina judged that it was enough and gave Rei a nod.
At that nod, Rei slipped the Ring of the New Moon back onto his finger.
Instantly, the overwhelming mana that had been assailing Odoban vanished, and she felt relief even as she turned a gaze of awe toward Rei.
"Who... who exactly are you? For a human to harbor that much mana within them... I can't believe it. This kind of, this kind of mana..."
"Calm down. Rei isn't going to attack you or anything. Come on, take a deep breath."
At Marina's words, Odoban breathed in deeply and exhaled, exhaled and inhaled.
She repeated the deep breathing several times, and having finally calmed down, she turned her gaze back toward Rei.
"That ring, could it be..."
"Yeah, it's probably what you're guessing—an artifact of the Ancient Magic Civilization."
"An artifact..."
As Odoban muttered in a daze, Marina flashed a mischievous smile and spoke.
"Understand now? There's no doubt that if Rei is here, we don't need to worry about supplying mana to the World Tree. Well, having Elena-sama present would already eliminate any concern... but what do you say? Will you come with us?"
To Marina, Elena was an asset far too valuable to pass up.
Her mana was extremely high, her personal combat skills were unquestionably first-class, and unlike most high-rank adventurers, she also possessed common sense.
Additionally, while it would carry no meaning in the forest of Marina's homeland, the fact that she bore the alias of Princess General—a symbol of the Noble's Faction—would surely prove effective if anything happened on the journey there.
Such ulterior motives were part of it, but at the same time, Marina understood from her experience as a woman that Elena would be sad if she couldn't stay with Rei.
"Hey, before you ask her, I haven't actually decided to accept that nomination request yet, you know."
Noticing that the conversation had somehow proceeded on the assumption that he would accept the request, Rei interjected.
In response, Marina directed a sultry gaze at him and spoke.
"Oh, you won't accept? The reward for this request is something I think you'd be really happy about, Rei."
"...I'd be happy?"
To be honest, Rei was already inclined to accept Marina's request.
Marina was someone close to Rei, and unless it was an unreasonable request, he had no intention of refusing.
The reason he said something teasing was because the conversation had been progressing as though he would accept the request without his own will being involved.
But Marina, as if convinced that Rei would absolutely accept the request once he heard what she had to say, continued speaking.
"Yes. As I believe I mentioned earlier, what we want to ask of Rei is to pour mana into the World Tree and treat it. As a reward for that, I intend to pay you with several pieces chosen from among the World Tree's branches, leaves, sap, and amber."
Just how precious those items were, Rei couldn't fully grasp.
Even so, since they were parts of a tree called the World Tree, he could at least understand that they must all be extremely rare materials from an alchemical standpoint.
(Amber, if I recall, is fossilized tree sap, right? ...The World Tree is still right there, so would it produce amber? Well, this is a world where magic and such are commonplace, so I suppose it's only natural that something like that would exist.)
He wasn't particularly knowledgeable about gemstones, but he did remember seeing amber with a mosquito trapped inside on TV back in Japan.
(If it's World Tree amber, it's probably highly valuable in terms of rarity, and it should be top-class as a material. Even the branches would be a coveted material for mages making wands. The leaves and sap are probably for more potent potions or something like that?)
He considered various possibilities, but in the end, all he could really conclude was that they were extremely rare materials.
"What do you think? I imagine there's a lot for you to gain, Rei. Besides, due to the World Tree's illness, apparently all sorts of monsters have been gathering in the forest. If you have a hobby of collecting Magic Stones, Rei, you wouldn't want to just ignore that, would you?"
Hearing "Magic Stones," Rei, who was already drawn to the World Tree materials, made his decision.
"Alright, I'll accept that request. ...What about Elena, Vihera, and the others? I'm the one who accepted this request, so I'm not going to force you to—"
Rei was about to say "come along," but before he could, Elena spoke.
"I originally came to see Rei. If Rei is going, then naturally I shall go as well. Fortunately, it seems my mana will also be of use regarding the World Tree matter."
"Rei's going, and Elena's going, right? Then naturally, I'm going too."
"If Elena-sama is going, then of course I shall accompany you as well."
"Mm."
Everyone nodded... and thus, Rei accepted Marina's request together with Elena, Vihera, Ara, and Byune.