May 14th.
"Well, what should we do today?"
Over the complimentary breakfast in their guest room, Jin consulted with Elsa.
"I had a thought."
"What is it?"
"I was wondering if we could invite Lishia-san as a short-term instructor to teach the Medical Squad."
"Ah, Lishia, huh?"
Lishia was also an expert in Healing magic. Now that she had become a homunculus, her skills had reached even greater heights. Jin felt that having her teach at Avalon as Elsa's assistant would certainly enhance the effectiveness of the training.
"Let's check with her schedule later, then."
"Mm....So, what will you be doing, Jin-nii?"
"Let's see... I'll spend the day at the Go-lab to finalize the magic circle projection technology."
"Even though we already have things like the treatmenter for Healing magic?"
Elsa asked if there was any real point in going out of their way to develop something with inferior performance when superior magi-devices already existed.
"There is, actually."
"What is it?"
"Mana consumption and range."
"Ah..."
Back during the magical consumption fever outbreak, they had used Pegasus 1 to project Healing magic, but that had only been possible thanks to an ether converter and mana driver boasting astronomical output. Furthermore, that projection couldn't discriminate between targets. In other words, if used during combat, Healing magic would mend enemies alongside allies.
"Taking those two factors into account, it has its uses, right?"
"...That makes sense."
With that explanation, Elsa was convinced.
"Other than that, I'm still concerned about the Jagus Principality."
Laojun was supposed to be looking into the matter, so Jin planned to head back to Hourai Island soon to hear the report.
"And what are your plans for today, Elsa?"
"A continuation of yesterday—or rather, wrapping up some loose ends."
"Got it."
Jin suggested that once they took care of their errands and had lunch, they should return to Hourai Island for a bit.
"Mm, agreed."
The two of them had stayed longer than originally planned.
"I'm also curious about the circuit track construction in the Kingdom of Franz and the Adriana Memorial Hall project in the Shouro Empire," Jin added.
"Laojun should be keeping an eye on those, so I'm sure we'll get a message if anything happens, but..."
"I know that, but I can't help wondering all the same."
Following that conversation, Jin headed to the Go-lab while Elsa made her way to the Medical Squad to wrap up their respective unfinished business. Their escorts were Reiko and Hope, respectively.
"Elsa-sama, good morning. We have been waiting for you."
When Elsa arrived at the Medical Squad, May was there to greet her.
"Good morning....How is it? Have you gotten used to using it?"
"Yes, completely!"
The members deeper inside the room nodded vigorously in agreement. However, every single one of them had bloodshot eyes. Apparently, they had been taking turns using the 3D anatomical model non-stop.
"S-So, are there any questions?"
Slightly overwhelmed by their intense fervor, Elsa decided to field questions first so that nothing would be left unresolved.
"Ah, yes....Um, it's more of a request than a question, but we would really like one more—or preferably two more—of these 3D anatomical models..."
Her voice trailed off slightly toward the end, but the eagerness in her request was unmistakable.
"Mm, I have already considered that. Once I return to my base, I plan to send you models loaded with updated data."
Elsa explained that she had identified a few minor areas for improvement during the demonstration, and she wanted to address them first.
"Thank you so very much!"
Hearing that, the Medical Squad members—starting with Pollyanna Pendleton, who had raised the question—beamed with joy.
Meanwhile, with Jin:
"I plan to head back around noon today," he announced to everyone at the Go-lab.
"Aw, really? That's too bad."
"Yeah, seriously. Researching alongside you was so much fun, and we made so much progress."
Eira and Groma both voiced their disappointment. Kachea, however, remained thoroughly proactive.
"In that case, let's talk about all sorts of things until lunch!"
Of course, what Kachea meant by "talk" was far from idle chatter...
"Jin-san, regarding this combination here, wouldn't it be more efficient to arrange it like this?"
She dove right into three-dimensional magic circles, while Eira eagerly chimed in:
"Jin, about that beetle-type flight unit! If we design it right, I think it could fit directly onto a golem's back!"
Groma, for his part, had already begun exploring a transition from a simple pinhole setup to an assembly with lenses:
"Regarding this magic circle projection technology, I really think incorporating a lens could extend its range considerably."
Among these topics, the projection technology seemed in greatest need of guidance, but...
"Lenses are tricky... You won't get good results without a lot of trial and error."
Jin was a complete amateur when it came to optics, leaving him unable to offer any actionable advice.
"I'll give it a shot once we get official authorization."
Groma Tray was brimming with enthusiasm. At this rate, Jin felt the three of them might naturally branch off into their own areas of study: Groma on projection, Kachea on three-dimensional magic circles, and Eira on the beetle-type flight unit.
Then, as noon drew near:
"Jin-san, I've been meaning to ask..." Kachea began hesitantly.
"What's on your mind?"
"Um, well, about magic circles. You mentioned that a projected magic circle won't activate without a trigger, but does that also apply to one drawn on paper, for instance?"
Since Kachea couldn't use magic herself, such questions naturally piqued her curiosity.
"And for example, if an active magic circle is displayed on a magi-monitor, will the spell trigger on the screen itself?"
"...I see where your confusion lies."
Jin decided to explain it step by step.
"Generally speaking, a magic circle won't activate unless mana is channeled into it. You understand that part, right?"
"Yes....Which means an ordinary magic circle won't activate just from being projected or displayed."
"Exactly."
If it did, simply copying down a magic circle would cause it to go off immediately. That would be absurdly dangerous.
"A person with mana can activate a drawn magic circle by channeling mana into it to trigger the effect."
However, magic circles calibrated for universal use didn't work that way. The same held true for the three-dimensional magic circles he planned to implement in magi-devices.
"And to channel that mana..."
"You need a trigger, right?"
"Spot on."
Jin was pleased to see Kachea grasping the underlying theory so well. It would undoubtedly aid in constructing three-dimensional magic circles. Eira and Groma also listened intently, clearly fascinated to see how the explanation would wrap up.
"Trigger magic circles are extremely unique," Jin continued.
"And what makes them so special is..."
"Ah—because they activate entirely on their own, right?" Kachea answered before Jin could finish.
"Exactly. Just drawing one is enough to set it in motion—that's what a trigger magic circle does. I explained that much before, right?"
"Yes."
"Now, there's another property I haven't mentioned yet. And that holds the answer to your question."
"Which is?"
"It produces no effect whatsoever."
"Huh?"
"Well, saying 'none' might be a slight exaggeration. It has no effect other than serving as a trigger."
"Ah, I see..."
"Its operation is confined strictly to the level of free ether, so it generates zero physical force."
In short, it caused no observable magical or physical phenomenon in the external world.
"That's why this magic circle alone is completely harmless, whether you write it down on paper or project it as an image."
To sum up: ordinary magic circles would never activate on their own, and the only type that did—the trigger magic circle—was completely inert, meaning it posed no danger regardless of the medium it was drawn on.
"I understand completely now."
And with that, the morning drew to a close.
"Jin, thanks a ton for all the advice!"
"Jin-san, thank you so much for everything!"
"Jin-dono, we'll take it from here and do our absolute best!"
"Jin-san, the next time you visit, we'll have results to show you!"
The members of the Go-lab offered their heartfelt thanks and voiced their future ambitions.
"I had a wonderful time as well. Thank you. Once my other business is settled, I'll come visit again."
Jin expressed his gratitude in return.
With early summer just around the corner, both the sky and the sea stretched out in brilliant, crystal-clear blue.