The amphibious vehicle intended as a gift was finally completed by that evening.
"Ooh, it’s done, Jin!...Though I guess I only helped out a little."
"No, Eira, you helped quite a bit. Besides, you could probably make another one yourself now if you had to, right?"
"Hmm... Well, maybe, if I were allowed to take as much time as I wanted."
"See? Then you can't say you only helped a little."
While it was true that Jin had done more than half the work, Eira had certainly been useful, and Kachea had contributed significantly to the design.
"It was fun working as a team for the first time in a while," Jin added without hesitation.
"Yeah, I felt the same way."
"M-Me too!"
The three of them shared a collective smile.
"By the way... what happened to Groma and... what was it called? The teacher from the Go-lab?" Jin asked, realizing his question was a bit late.
The Practical Golem Research Lab—or the Go-lab for short—was a facility at the absolute forefront of golem research, where Marikka had once served as an instructor.
"You're a bit behind... The teacher went back to their home country for a vacation. Oh, but Groma didn't go with them."
Apparently, he had stated he had no intention of returning to the Mercana Principality anytime soon.
"He accompanied the teacher to the Kingdom of Egerea instead."
"Ah, I see."
It seemed it was for the sake of broadening his horizons. Jin thought that sounded exactly like the earnest Groma Tray.
"So, we’re just house-sitting. But thanks to that, I got to work on this interesting project with Jin."
"Don't mention it."
They made a promise to have dinner together after Jin and the others had rinsed off their sweat in the bath.
Jin soaked alone in the men's bath. First, he spent time in a saline spring made from seawater, which warmed his body to the core. Next was a baking soda spring that left his skin feeling smooth. Finally, he finished with a soak in the simple springs before getting out.
As Jin sat in the breakroom drinking cold juice, Eira and Kachea arrived as well.
"I think I'll have a drink too."
"Me too."
After relaxing for a while, they had dinner together at the cafeteria. They made plans for the next day and retired early for the night.
The plans for the next day, of course, involved creating more gifts. Not satisfied with just the amphibious vehicle, they intended to make something more.
"I was thinking about it before I went to sleep last night," Jin said. "Since this is for a king, I thought an ornament might be better than a tool. Like a rock crystal sculpture."
"Ah, definitely," Eira agreed, her voice lacking even a shred of reverence. "Flashy gold ornaments and things like that seem like exactly what a person in power would like."
"And so," Jin continued, recalling Stearena Gamma, who had once been a member of the Jin Family. "Let's make a crystal golem."
"A—a crystal golem?!" Eira cried out, astonished. Kachea's eyes went wide, though she didn't quite grasp the level of technology being discussed.
"Well, it doesn't have to be rock crystal. Diamond or ruby would be fine too." Jin wondered aloud when the New King's birthday was, and Reiko provided the answer.
"It is in September, Father."
"I see. In that case, sapphire."
The concept of birthstones wasn't very common in this world, but Jin liked to stick to the theme. Besides, sapphire was easy to synthesize.
"As for alumina... we have some."
As a heat-resistant material, alumina—or aluminum oxide—was used even here in Avalon for various purposes, including crucibles.
"What are you going to do with that, Jin?"
"Sapphire is corundum, which is essentially crystallized aluminum oxide."
After getting permission from Kachea, Reiko brought over bags of alumina from the storehouse. These were powders normally sintered to make crucibles or other heat-resistant materials.
"About 200 kilograms should be enough."
The specific gravity of aluminum oxide is roughly 4. To make a human-sized model equivalent to about 50 kilograms, Jin calculated that 200 kilograms would be necessary.
"Jin? Just what are you..."
Before Eira could finish her question, Jin activated his magi-craft.
"Crystallization."
"Whoa!?"
The powdered alumina crystallized, transforming into transparent corundum. As the name implied, Crystallization was a spell that promoted the process of forming crystals. Because it consumed a large amount of mana, it was not a magi-craft spell just anyone could perform.
"Now then, I need to add some color."
By mixing a trace amount of iron and titanium into the corundum, it would take on that characteristic blue hue.
"Add. Homogenize. Crystallization."
"Oh?"
"Wow..."
After adding the trace elements and dispersing them uniformly, he crystallized it once more, creating a solid block of blue sapphire. Both Eira and Kachea were captivated by the beauty of the gem and Jin's masterful technique.
"That should do it. Reiko, I'll need some mithril too."
"Yes, Father."
Adding mithril would make the color slightly cloudy, but it was a necessary sacrifice to make the body more conductive to magical energy. Even then, the cloudiness was minimal; since it wasn't being used as jewelry, it wasn't a problem at all.
"Add. Homogenize."
The trick with mithril was not to let it crystallize.
"With this, the materials are finished."
"...That's incredible, Jin. As expected of a Magi Craft Meister."
"Truly..."
The two were filled with wonder.
"Eira, I want you to make the golem's body with this. Kachea, I'd like you to decide its proportions."
"R-Right."
"Y-Yes."
While Eira and Kachea prepared the body, Jin worked on the control core. The know-how for the Forming drive had been perfected by Stearena.
"Jin, how is this?"
Eira and Kachea had created an adult female-type body. It was about 160 centimeters tall with glamorous curves, and its hair was sculpted into a short-cut style.
"Oh, it's beautiful. Excellent work, you two," Jin praised.
"All that's left are the sensors."
"I don't understand that part at all," Eira said. "I'll just watch and see how you do it."
"Is that so? I'd like for the Go-lab to research that eventually, too. Well, watch closely."
"I will. I'll definitely use it as a reference," Eira declared, leaning forward to catch Jin's every move.
Kachea also watched intently, notepad in hand.
"This is how you do it," Jin said as he began the additional processing.