"I see..."
Jin was finally convinced.
While Jin had used magi-crystals as power sources in the past, he had never actually exhausted their mana completely.
Since magi-crystals were far too expensive to be used as mere batteries under normal circumstances, he had never encountered this specific phenomenon before.
"Usually, you'd engrave a magi-formula into one and use it as a magi-device. With that kind of application, you probably wouldn't even use ten percent of the mana stored inside," Stearena surmised, her thoughts mirroring Jin's.
"That's likely the case. I'm sure they must lose weight relative to the amount of mana consumed, but..."
The problem was that no one knew the weight of mana or free ether. The common understanding was simply that they possessed almost no weight at all.
"What this tells us is that it's highly likely the mana doesn't just slip into gaps in a crystal structure, but rather that the mana and the crystal form simultaneously."
In other words, the presence of mana was a requirement for the crystallization process to occur.
"But we still haven't figured out what the other components are," Elsa noted regretfully.
"No, I can take a guess."
"What?"
"I don't know of any other substance that simply vanishes when its mana is gone. Which means..."
"...It's a substance made from free ether?"
"Exactly. That's my theory. For now, let's call them 'magiatoms'."
"Magiatoms..."
Having already learned the fundamentals of science, Elsa was able to keep up with Jin's logic.
"They are made of magi-particles like magitrons, magiprotons, and magielectrons. And those magi-particles are formed from free ether."
"...And their interaction with mana is what creates a magi-crystal?"
"Precisely. You're quick, Elsa."
Elsa’s mind was working fast.
"If it's a low-quality magi-crystal, there should be some sort of residue left behind once the mana is spent."
They were able to verify this through further experimentation.
When a low-quality magi-crystal was exhausted and disappeared, a tiny amount of mineral powder remained.
Furthermore, they confirmed that magi-crystals of the quality generally found in circulation—as opposed to those from Hourai Island—would outwardly remain unchanged but turn into ordinary, mana-less stones once depleted.
＊ ＊ ＊
With a solid lead established, the group took a short break.
"Well, we have a working hypothesis for the nature of magi-crystals."
"Oh, Jin, if only I could use Trans Info! I want to know more about science!"
"As do I!"
Saki and Stearena shouted, their voices full of genuine longing.
"Wait... that's right. I haven't checked your aptitudes yet, have I?"
Jin decided to take this opportunity to test their compatibility with Trans Info.
"Alright, the magi-formula goes like this, and the keyword is this."
He gave Saki and Stearena the same explanation he had once given to Reinhard and Elsa.
"Don't worry about getting it right on the first try. We're just looking for your aptitude level."
"Understood. Trans Info."
"Then I shall try as well. Trans Info."
Reiko monitored the flow and behavior of their mana.
"...Well?"
"Saki-san and Stearena-san both seem capable of reaching level 3."
Level 3 was the same rank Elsa had started with. With training, it was possible to increase that by a level or two. Indeed, Reinhard had managed to reach level 3 himself. Elsa, meanwhile, had progressed to level 5.
"At level 3, you can learn basic concepts."
"Is that so? Then please, Jin, do it now!"
"I beg of you as well!"
It was already midday, but Jin gave in to their enthusiasm and decided to perform a Trans Info transfer of the same knowledge he had given to Reinhard.
Since he hadn't erased the magi-crystal he'd used for Reinhard, the preparations were finished in no time.
"Trans Info."
"Trans Info."
First, the knowledge was moved from the source magi-crystal to a secondary one. Once they transferred that into themselves, the process was complete.
"............"
"......"
The two were momentarily stunned by the sheer volume of information they had received. Knowing exactly how they felt, Jin and Elsa left them alone and began preparing lunch.
In truth, it was mostly just a matter of bringing over what Perido had already prepared, and even then, Reiko handled the bulk of the work.
Since Jin, Elsa, and Saki had only recently traveled from Kaina Village, not much time had passed since breakfast, so they kept their portions modest.
Using yeast-leavened bread with meat patties and vegetables, they were essentially eating hamburgers.
"These are delicious."
Stearena polished off three, while Jin had two, and Elsa and Saki had one each.
＊ ＊ ＊
"Now for the next step: how free ether becomes magiatoms."
Once the meal was over, Jin brought up the next topic.
"Do magiatoms and mana combine to create magi-crystals?...Man, if my father heard this, he'd jump all over it."
Saki was referring to her father, the renowned alchemist Toa Eschenbach.
"By the way, Saki, where is your father right now?"
"...Apparently, he came home once while I was at my grandfather's place. He stayed for two or three days and then vanished off to somewhere else again..."
The man simply couldn't stay settled in one place.
"I-I see..."
Jin pulled himself together and refocused the discussion.
"Anyway, regarding how free ether turns into magiatoms."
By now, all four people present understood the basic concept of atomic structure. Even if it was a simplified model, it was more than enough for the current discussion.
"To begin with, we haven't even fully demystified the activation of magic," Stearena noted.
"Magi absorb free ether from the atmosphere—perhaps through breathing—and refine it into mana within their bodies. This mana can be converted into various forms of energy based on the will and visualization of the person who refined it. That energy can then be manipulated. That's my understanding of what magic is."
"...What?"
"...Is that more knowledge from... Adriana Barbora Tsetse-sama?"
Jin nodded to the two stunned women.
"Yes. In these specific fields, modern knowledge has fallen behind. It's a consequence of the Great Magic War."
They digressed frequently, but that was the nature of a conversation between close friends.
"...So, mental energy transforms free ether into mana? If that's the case, then couldn't it also create magiatoms?"
"That's what I'm thinking."
As he agreed with Saki's point, Jin considered that magi were quite similar to what were called psychics on Earth. At the very least, that classification seemed to fit.
The fact that not everyone could use magic made magi and psychics quite similar indeed.
"...Then what about magiatoms found in nature?"
Jin brought his focus back at Stearena's question.
"I'm interested in that too, but let's return to our primary goal: creating artificial magi-crystals."
"True. If we get too greedy, we'll never get anywhere."
"In that case, if we know the structure of an atom, we might actually be able to create magiatoms ourselves," Stearena said, reaching the heart of the issue.
"Exactly. It's probably best to start with the simplest atomic structure."
"Hydrogen, right?"
"Yes. Though hydrogen is a gas and therefore invisible. We'll need to be a bit clever."
They decided to use a common method for collecting gas: submersing a cup in water, turning it upside down, and then releasing the gas into it.
Since free ether was present even in water, all that remained was to figure out how to convert it into hydrogen.
"..."
"............!"
The four of them attempted various ways to generate hydrogen.
The general approach was to visualize the structure of hydrogen and attempt to transform the free ether inside the cup, but it was far from easy.
The first to succeed was, unsurprisingly, Jin. It was likely a matter of the strength of his visualization.
"I've got it!"
"Oh, a gas is definitely forming. Analyze... Hmm, no doubt about it, it's hydrogen. Well done, Jin."
The Analyze spell wouldn't reveal things the caster didn't already know, but since Saki now understood both the existence and the structure of hydrogen, she was able to identify it.
Having seen Jin succeed, Elsa, Saki, and Stearena eventually followed suit. Having a successful precedent to observe seemed to be a powerful aid.
In any case, they now knew for certain that it was possible to create atoms from free ether. However...
"...J-Jin, I feel kind of... sluggish."
"...I do as well."
"...Me too, a little."
With the exception of Jin, the other three began complaining of sudden lethargy.
"You are suffering from mana depletion," Reiko diagnosed. It seemed the art of transmutation was not a task to be taken lightly.