On May 12th, shortly before 8:00 AM local time, Deus Ex Machina's Aristotle was preparing to depart from Avalon.
Just then, another airship flew in.
"Oh, Jin has arrived."
Indeed, it was Jin's Hurricane.
The Hurricane touched down alongside Maquina's Aristotle.
Resting next to the hundred-meter-long Aristotle, even the forty-meter Hurricane looked small.
It served as a clear display of Deus Ex Machina's sheer military might.
"Hey, Maquina."
"Hey, Jin."
Jin and Maquina exchanged a brief greeting.
"Jin-dono, I apologize that I can only offer a brief greeting."
"It's quite all right, please don't worry about it."
Tomax Bartman spoke with an apologetic expression as well.
"Let's catch up properly sometime soon. Elsa-dono as well."
"Indeed."
"Mm."
"Jin-sama, Reiko-san, let us take our time to talk next time."
"Yeah. Take care as well, Elena."
With that, Maquina and his group boarded the Aristotle.
"Jin-sama, Elsa-sama, Reiko-san, Hope-san, please allow me to show you the way."
The secretary automaton Manon arrived to guide Jin's party.
The Aristotle took off slowly, ascending into the vast sky.
Jin's group was first shown into a small conference room.
"Today, Jin-sama will visit the Go-lab, and Elsa-sama will tour the medical unit. Is that correct?"
"That works for me."
"Mm, that's fine."
And so, Jin and Reiko split off to head for the Go-lab, while Elsa and Hope made their way to the medical unit.
"Ah, Jin-san."
"Yo, Jin, you made it."
Kachea and Eira noticed Jin and came over to welcome him.
"Last time, things were too chaotic with the Revolutionary Party mess to really sit back and chat."
"That's true."
"It really was."
"So, I wanted to discuss something with the three of us together—Kachea, Eira, and me—for the first time in a while."
"What is it?"
"Ah, could it be that?"
Eira tilted her head quizzically, while Kachea seemed to have already guessed what he meant.
"At any rate, please come this way."
Jin and Reiko were guided to the conference space at the back of the Go-lab. Kachea brewed some tea for them.
"Where are the other members?"
"Groma and the others went to test the new mini-golem. It's a joint project with the Aviation Research Lab."
"Ah, so they've gotten totally hooked on making small golems, huh."
"Pretty much. Building smaller golems and airframes saves materials, cuts down on time, and hones your technique."
Eira said as she took a sip of the tea Kachea had prepared.
"...So, they went out for a test flight of the Blow Floater—though I've honestly lost count of which model number it's on by now."
"I see."
"As for Eira-san and me, we volunteered to stay behind and mind the lab since we heard you were coming, Jin-san."
That explained why only the two of them were here.
"Did I make you go out of your way?"
"No, no, not at all."
"Exactly. Once you've watched it fly so many times, the thrill wears off anyway."
"That sounds like you, Eira."
Jin chuckled. Then Kachea chimed in:
"Well, to tell the truth, she just prioritized you, Jin-san."
With her real motive blurted out, Eira grew flustered.
"H-Hey, Kachea, don't just blab it out!"
"Haha, thanks."
With that, Jin spread the materials he had brought onto the table.
"This is the magic circle we put together over on the 'other side' back then."
"Ooh, wow, that brings back memories! Back then, we couldn't even use a single magi-crystal freely!...Hmm, looking at it now, the activation efficiency is terrible!"
"Yeah. But even so, I think it still has its uses."
Because they had more breathing room now, they could sort and categorize applications based on specific needs.
"I think it's well-suited for running for long periods at a constant output."
At Jin's words, Eira nodded in agreement.
"I feel the same way. It's not really meant for applications where you need to constantly ramp the output up and down."
"In that case, it might be well-suited for water-lifting pumps," Kachea suggested.
"Oh, yeah. That's a great use for it."
Jin and Eira both agreed that this kind of magic-circle-based magi-device would work well for pumps that ran around the clock.
"Or maybe for heating water in a bathhouse," Jin added.
"You really do love your baths, don't you?" Kachea teased.
"U-Uh, anyway, here's a magic circle I've been experimenting with myself."
Clearing his throat with a light cough, Jin spread another sheet of paper across the table.
"Oho, this is..."
Eira let out an appreciative hum.
"Instead of a multi-layered structure, you're making it spherical?"
"Right. When jumping across operational branch points, this cuts down on time loss."
"Since it's engraved onto a magi-circuit plate, you can shape it like this! As expected of you, Jin!"
Non-crystalline stone plates, such as quartz, were used for magi-circuit plates.
Therefore, by using Fusion, one could combine small magi-circuit plates or scrap materials into a large base material.
"Gotta love magi-craft."
Eira enthusiastically began exploring potential applications.
"Hmm, so this is how you put it together, Jin."
"Yeah? Did you come up with a good idea, Eira?"
"Looking at your spherical magic circle gave me an idea. Even without going all the way to a sphere, you could do something like this..."
In the margins of the paper, Eira sketched multiple magic circles joined together three-dimensionally at angles.
"For simple operations, I think something like this should be plenty."
"Ah, I see."
The concept was similar to engraving magic circles onto the faces of a cube in order to combine six of them.
"True, there are probably plenty of magi-devices that could get by with just this."
If it only required four magic circles, a regular tetrahedron would work just as well.
"Depending on the number of branches, wouldn't polygonal prisms work too?" asked Kachea, whose strengths lay in mathematics.
"Yeah, they would."
"It looks like it'll be really interesting to explore this through three-dimensional magic circles."
And so, Jin, Eira, and Kachea continued their discussions together as a trio for the first time in quite a while.