While night had fallen over the Norha Principality, it was broad daylight on Hourai Island.
The members of the Jin Family felt genuine sympathy regarding the meager diet in the Norha Principality.
"To think they have to get creative just to eat wild weeds... Maybe I should teach them about other edible plants?"
Seeing Goose about to veer off in an unexpected direction, Saki chimed in to keep him grounded.
"Kufu, that's all well and good, but right now we're talking about aid in the form of magi-devices."
"Well, just like Beena mentioned earlier, a magi-device that desalinates seawater into fresh water would probably be our best bet."
"Yeah, absolutely."
Reinhard nodded in agreement with Jin.
After all, the two of them had previously developed a distillation magi-device in the Kingdom of Elias at the behest of Marchioness Firenziano.
"As long as it runs continuously, controlling it won't be much trouble either."
The real challenge lay in the method.
When it came to distilling seawater through heating, relying on magic circles was far too inefficient compared to using magi-crystals.
"A barrier, perhaps..."
The core principle was similar to that of a semipermeable membrane.
Essentially, a barrier would divide a seawater-filled container into two compartments.
This barrier would let water molecules pass freely in both directions, while allowing all other molecules to travel only one way.
Given enough time, one side of the container would become nearly pure fresh water, while the other would end up with a heavy concentration of minerals, particularly salt.
"If it's meant for irrigation rather than drinking water, it probably doesn't even need to be completely pure, right?" Hanna noted.
"Depending on the levels, having a few minerals left in the water might actually promote plant growth."
"That's a very good point," Jin agreed.
"Though we'd definitely want to strip out bioaccumulative elements... like arsenic, mercury, and cadmium."
It was a perspective uniquely informed by Jin's knowledge of pollution-related diseases.
"Say, in that case, what if we made a bunch of magi-devices that 'extract' specific elements from seawater and installed them along the waterways?"
Beena offered a fresh perspective.
Through a similar technique, Adriana Barbora Tsetse, the First Generation Magi Craft Meister, had successfully harvested metal materials from seawater in the early days of her youthful travels.
"Hmm, the issue is that there are just so many elements to filter out..."
Lithium, sodium, potassium, gold, silver, copper, iron, nickel, arsenic, bromine, fluorine, boron, iodine, radium, uranium, plutonium, cesium, phosphorus, sulfur, gallium, indium, magnesium, silicon, germanium, chlorine...
There were 103 elements known to Jin and cataloged in the academic texts brought over by the magus Shuuki Tsetse—all the way up to lawrencium.
Of course, transuranic elements heavier than uranium existed in nature in only trace amounts, meaning they could largely be disregarded, but that still left 92.
Setting aside hydrogen and oxygen, the components of water itself, that meant roughly 90 distinct elements would require removal.
"That's quite a daunting task," Jin muttered.
"...Wait a second."
A sudden realization struck him.
At that exact moment, Beena spoke up almost in unison with him.
"We just have to flip our thinking."
"We can just look at it in reverse, can't we?"
"...What's got into you two?"
Reinhard looked between them, puzzled.
"...Go ahead, Beena."
"No, you first, Jin."
After bouncing the floor back and forth a few times, Jin took the lead to explain.
"Basically, I was wondering what would happen if we let water flow across that barrier we were just talking about—the one where water moves both ways, but everything else only goes one way."
Hearing Jin's explanation, Reinhard caught on immediately.
"Oh! Then pure water would just drip right through, wouldn't it?"
"Precisely."
It turned out Beena had arrived at the exact same conclusion.
"Jin beat me to the punch. I was picturing pouring water into a container enclosed by barriers, but that would just cause the concentration inside to build up over time."
She readily conceded that Jin's design was far more practical than her own.
"So in short... we pump up seawater and channel it along a gutter lined with the barrier. Fresh water drips out through the bottom, while the increasingly saline seawater flows right back into the ocean. And we just cycle that endlessly."
Reinhard neatly summarized the entire mechanism.
"That's the gist of it. This keeps the whole operation steady, and the magi-device itself only needs two functions: pumping seawater and maintaining the barrier that filters fresh water."
"Right, exactly as Jin said... Though having Avalon take credit for developing this might be pushing credibility a bit, wouldn't it?" Reinhard asked with a faint sigh.
"I suppose our best option is to frame it as a donation from Deus Ex Machina."
"I think you're right..."
Consulting the rest of the Jin Family confirmed that everyone was on board with the plan.
Meanwhile, in the Norha Principality.
Inside their quarters at the Guest House, Gajue Tsuga, Fione Fias, and Manon were reviewing the results of their diplomatic meeting.
Naturally, they had thoroughly swept the room for eavesdropping before raising a sound-insulation barrier.
"That turned out to be quite a fruitful discussion."
Gajue Tsuga exhaled a breath that sounded half like a deep sigh of relief.
"Do you believe what they told us was genuine?"
"I believe they were being truthful," Fione Fias replied, voicing her confidence in their hosts.
"Yes. I also evaluate that they were not being deceitful."
With Manon concurring, Gajue Tsuga gave a satisfied nod.
"Good. In that case, following a brief meeting tomorrow morning, we will depart back for the garrison. Is there anything else we need to clarify before we go?"
Given the rare opportunity, Gajue Tsuga wanted to gather every piece of intelligence they could.
"Well... I would love to know the Norha Principality's military strength, though I imagine asking outright is out of the question," Fione Fias said wistfully.
"If we could gauge Norha's military capabilities, we could extrapolate the strength of the Jagus Principality as well."
"I understand your desire, but that falls squarely under their highest state secrets," Gajue Tsuga said with a wry smile.
"...Even so, we might still be able to glean a glimpse of their capabilities, you know," Manon interjected.
"Manon? What are you suggesting?"
"Tomorrow, I can disclose that I am an automata and request a sham fight against their combat golems. Through that engagement, we will be able to measure the baseline performance of their golems."
"I-I see... But wouldn't that carry immense risk?"
"She's right! What if you end up destroyed, Manon?!"
Manon merely offered a calm smile in response.
"Rest assured, even if I am damaged, I can always be repaired. Stepping up in situations like this is precisely my duty as an automata."
"Manon..."
"Besides, I have no intention of breaking that easily. After all, the one who created me was Jin-sama—the present-day Magi Craft Meister."