On the morning of July 19th, Jin, Elsa, and Saki headed to Hourai Island. Berche, meanwhile, returned to Kalts Village where Reinhard was waiting.
Stearena was already on the island. She had been staying there ever since her return from her home in Goua, in the Celuroa Kingdom, back on the 16th.
"Oh, Jin-kun, everyone."
Stearena had been granted a private research lab in a room on the third floor. Jin and the others poked their heads in to greet her.
"What brings you all here today?"
"There’s a topic I’d like you to weigh in on, Stearena," Jin replied.
"My, what could it be?"
Jin explained his goal: the artificial creation of magi-crystals. Upon hearing this, Stearena practically leaped for joy.
"I love it! That’s exactly the kind of work I’ve wanted to do! I adore crystals, beautiful gemstones, and magi-crystals, but they shouldn’t just be treated as mere components for golems!"
With her on board, they moved on to the specifics. Jin opened the discussion.
"You’re familiar with the 'mana tanks' commonly used in golems, right? They store mana within a magi-crystal. Do any of you know the actual principle behind how that works?"
"Well... it’s embarrassing to admit, but I’ve always just used them without knowing," Stearena confessed.
In technology, some developments are born from empirical observation, while others stem from pure theory. The mana tank was a product of the former—a technology discovered through a long process of trial and error.
"Everyone, try to think about how mana might be stored inside a mana tank."
"...I haven't a clue," Saki admitted after a moment of thought. Stearena looked equally stumped. Elsa, however, remained deep in contemplation. Eventually, she looked up and answered in a small, hesitant voice.
"...Does it go into the gaps?"
"I believe you’ve hit the nail on the head."
Jin had already guessed Elsa's train of thought, seeing that it mirrored his own. However, Saki and Stearena remained puzzled. To clarify, Jin began a simple explanation.
"Imagine you have a box, and you fill it to the brim with large, round stones. Once the box is 'full' of those stones, is there room for anything else inside?"
"Hmm? If it's full, then nothing else would fit... No, wait. You could probably still pour sand in there, couldn't you?"
Jin nodded at Saki’s answer.
"Exactly. You said sand, but you could also fit water, right? In other words, as long as the sizes are different, there's always room for one thing to fit inside the other."
Stearena spoke up as the realization dawned on her.
"Does that mean mana is incredibly small?"
"I believe so. All matter is made of tiny particles called 'molecules.' Molecules are so small they're invisible to the eye, but mana is even smaller. And I suspect free ether—or ether—is smaller still."
Jin laid out his theory for them.
"While free ether and mana can permeate most substances, I believe magi-crystals are materials that can hold a vast amount of mana while also allowing for easy extraction. Of course, because you can write a magi-formula directly onto a magi-crystal, they are also incredibly efficient as tanks."
"I see... I think I'm following you. I’ll need you to explain that 'molecule' word more thoroughly later, but please, go on."
"Now, what if we could pack a high concentration of mana into a regular stone and keep it there?"
"...Would it become an artificial magi-stone?" Saki hypothesized.
Jin nodded. "If it were possible, yes. Unfortunately, when I did a brief test previously, it didn't work."
"I-I see. Even you couldn't do it, Jin...?" Saki's shoulders slumped.
Stearena, on the contrary, felt a surge of professional competitive spirit.
"But that’s exactly what makes this worth doing! Our goals are to investigate the true nature of magi-crystals and find a way to replicate them ourselves, right?"
Jin nodded. "Right. Let's start by trying a few things."
He asked Reiko to prepare a variety of different magi-crystals.
"First off, I've been wondering if we can learn anything from why magi-crystals have different colors based on their attribute..." Jin said, looking over the colorful stones arranged on the workbench.
"Hmm, that’s a good point. But what’s the actual difference between a magi-crystal and a magi-stone? Is it just the total amount of mana they contain?"
"Magi-crystals are mostly transparent or translucent, while magi-stones are opaque," Stearena observed. "I suspect the answer lies somewhere in that distinction."
"Ah, wait..."
Elsa seemed to have caught onto something.
"I think magi-crystals are, as the name implies, 'crystallized.' Their molecular arrangement is regular, which makes it easier for mana to enter. Magi-stones aren't like that."
Saki and Stearena didn't quite grasp the scientific nuance of the word 'crystal,' so Jin provided a follow-up.
"A crystal is a state where molecules—those tiny particles I mentioned—are lined up in a perfectly regular pattern. For example, rock crystal always forms a hexagonal prism."
The analogy seemed to help, as both women gave him a firm nod.
"To put it another way, you could say the gaps are neatly aligned. Think of a straight road versus a winding, cluttered one. Which one is easier to travel down?"
"As expected of Jin-nii. I never would have thought of an analogy like that."
At the very least, they agreed that a crystalline structure was likely a major factor in whether a substance could effectively hold mana.
"The next step, then, is determining whether mana enters these stones and crystals naturally."
If they could understand that process and replicate it, they might be able to create synthetic magi-crystals.
"Is that... the kind of thing we can figure out just by thinking about it?" Saki asked, her voice sounding a bit doubtful.
"Well, I think we can find some clues if we consider the environments where they're found."
"Environments?"
"Yeah. For instance, I know from experience that fire-attribute magi-stones are found near the volcano by Kaina Village. I’ve found earth attribute magi-crystals there as well."
This had happened during the previous year.
"You can find all attributes in the tunnels beneath Hourai Island, right?" Elsa asked.
Jin nodded. "Yeah. It seems there are points deep under this island where the free ether is exceptionally dense."
That prompted Elsa to share another flash of insight.
"...Does free ether combine to become mana?"
"What did you say?"
Jin stared at her in surprise. Feeling the weight of his gaze, Elsa looked down slightly.
"I see... If free ether is the atom, then mana is the molecule."
Elsa understood his murmur. "Yes. That’s what I was trying to say."
For the benefit of the two who were once again falling behind, Jin translated the concept.
"Think of an atom as... a building block. By itself, it’s just a piece of wood, but when you combine them, they can become a house or a castle."
This analogy was a hit.
"Oh, I get it! So fire, water, earth, breeze... each attribute is just free ether combined in a specific way?"
Saki looked delighted, and Stearena added, "And magic and spells are the methods used to create those specific combinations!"
Since both women already understood the basic concepts of free ether and mana, Jin was relieved he didn't have to explain the fundamental metaphysics.
"Wait, if that's the case... perhaps a magi-crystal is a substance where the gaps in the crystal are exactly the same shape as the mana of a specific attribute..."
The theory Jin arrived at felt like it was on the right track. It was like a mold—a positive and a negative.
He hypothesized that magi-crystals formed when free ether was drawn into a crystal whose internal structure perfectly matched the 'shape' of a specific attribute’s mana. While this didn't perfectly explain the all-attribute types yet, it made everything else fall into place.
"If that’s true, shouldn't there be magi-crystals out there that have run out of mana? I’ve never seen such a thing..." Stearena noted.
"I’ve seen plenty of magi-stones run dry, though," Jin replied. Both he and Stearena tilted their heads in thought.
"A magi-stone that’s lost its mana just turns into a regular stone, right?"
"Yeah. Though the color might fade slightly..." Jin looked a bit unsure, as he didn't work with magi-stones very often.
"Then why don't we just test it?" Elsa suggested.
She was right. If they didn't know what happened to a magi-crystal when its mana was depleted, they could simply run an experiment.
"Alright, let's do it."
Jin selected the smallest magi-crystal from the workbench to act as a power source and decided to activate a spell. To speed up the process, he needed something with high mana consumption.
"Okay, let's use a Magi-Jammer."
It was certainly one of the most mana-hungry magic tools in his repertoire. Jin asked Reiko to bring him a prototype. While she was gone, he gave a brief overview of what the device did.
"I see... it interferes with the activation of magic. How fascinating."
"You’ve developed some truly incredible things, Jin-kun."
"Father, I have returned with it."
As they spoke, Reiko arrived with the device.
"This one is set up for an ether converter, so I'll need to modify this part... and this..."
With a few quick adjustments, Jin converted the device to run on the magi-crystal. He also disabled the intermittent pulse feature used to save energy, setting it to a continuous drain.
"Alright. 'Wake up'."
Jin activated the modified Magi-Jammer.
"If you're standing on this side, you shouldn't be able to use magic anymore."
"Really? Let me see... 'Light Ball'... Oh, it’s true! I really can't use magic."
"Heh, how interesting. I’d love to have a long talk with you about the mechanics of this later." Saki was particularly intrigued by the fundamental nature of magic—after all, her alchemy thesis had been titled On the Function of Craft Magic and Mana.
Regardless, the Magi-Jammer, now modified for maximum consumption, hummed along for about ten minutes before it finally ground to a halt.
"Okay, let's see what happened."
Jin opened the compartment where he’d installed the magi-crystal.
"This is..."
The space where the magi-crystal should have been was now completely empty.