After lunch, Jin and the others returned to the Central Basin.
"Now then, Rubina, would you be interested in tinkering with one of the units other than the one we just modified?"
"Huh?"
Out of the ten units, one was being kept for preservation, leaving nine available for modification. Jin intended to upgrade four of them in total to serve as security for Hale. He thought he would let Rubina take charge of one of those units. Though she was still inexperienced, his goal was for her to grow through the process.
"I'll do it! I definitely want to try!"
Rubina, of course, accepted the offer immediately.
"Alright. I'll leave one to you after this, then."
"Thank you, Jin-sama!"
"Rubi-chan, that's wonderful."
"We'll help you too, Rubi-chan."
"Yeah, thanks..."
Rubina gave a sincere word of thanks to Rouge and Neige for their offer to assist.
Meanwhile, the Elder—No. 700672—headed back to the House with the adults, namely the Triharts and Amanda, to talk about various matters. These days, No. 700672 seemed to find such conversations quite enjoyable. He was becoming increasingly human-like.
"Rouge, Neige, I shall return ahead of you. Be sure not to be a burden to Jin-dono."
"Yes, Father."
"Yes, Father."
As for Marikka, she intended to serve as Jin’s assistant. Jin was about to begin the modifications on the human-sized Magi Puppets.
"It's only at times like these that I can truly observe your handiwork at my leisure, Jin-sama."
Marikka was an officially recognized disciple of Jin. She remarked that, just as it had been four hundred years ago, watching Jin work was an excellent way to study.
＊ ＊ ＊
Rubina and the others were full of energy.
"Hold that part down!"
"Got it."
"Help me lift this side!"
"Leave it to me!"
Neige and Rouge moved nimbly according to Rubina's instructions. For the large components, Rubina used Gravity Magic to lighten them so Neige and Rouge could move them into place. This method of applying Gravity Magic to massive, heavy parts was a technique Rubina often employed when constructing large-scale golems.
"Phew. That takes care of the disassembly."
"You're very good at this, Rubi-chan."
"Amazing!"
Neige and Rouge didn't show the slightest hint of fatigue.
"Well then, we still have a little time before three o'clock tea, so let's get the rust removal done too."
"Okay!"
"Yeah!"
Watching the three of them out of the corner of his eye, Jin finished disassembling the ninth human-sized Magi Puppet. He intended to keep one of these as a historical and technical legacy as well.
"...Jin-sama, your technique is... too mush-sh..."
Marikka was somewhere between impressed and utterly exasperated.
＊ ＊ ＊
"So sweet!"
"Delicious..."
"I love this."
For their three o'clock tea time, they enjoyed sencha accompanied by ankoromochi and fried okaki. As usual, Neige preferred her snacks with subtle sweetness, while Rouge had a taste for the heavily sweetened variety.
"These fried okaki seem simple enough to make, yet they are quite tasty," Marikka noted, crunching away on the snacks.
"Ah, the tea is excellent."
Jin was also quite satisfied, being able to spend time doing what he loved with his companions. Once tea time was over, it was time for one last stint of work before dinner.
"The material is iron-based, so I'll add some mithril to turn it into magi-steel..."
Jin judged that the situation didn't quite call for Neo-steel. With Reiko and Marikka assisting him, the task was completed in about thirty minutes.
"Now for the drive system."
Since these weren't biological materials, Jin pondered how best to proceed.
"Father, what if you created magi-duralumin using Neo-series materials?" Reiko suggested.
"Hmm, that sounds interesting. Let's give it a try."
While a shape-memory alloy has the property of 'remembering'—or reproducing—a specific shape at a certain temperature, magi-duralumin has the property of returning to its original shape when a specific amount of magi is applied. Jin had researched this in the past, but because it didn't quite measure up to biological materials like magical beast parts, he hadn't used it for his higher-end golems.
However, if he made it from Neo-series materials, which had an even higher affinity for free ether than magi-series materials...
"Yes, this is perfectly practical."
While its efficiency was lower than the Ancient Dragon hide used for Reiko, its maximum output actually exceeded magical muscles made from other materials. The only real drawback was that it was heavier than biological alternatives.
"Alright, let's use this."
With the verification experiments complete, Jin hurriedly began mass-producing the magi-duralumin. Reiko lined up the materials for him as he used Forming and Toughening to churn out standardized magical muscle components in bulk.
Marikka’s job was to assemble them, but the rate at which Jin produced the magical muscles was far faster. She felt as though she were being chased as she frantically put the parts together. Once Jin finished making the necessary number of magical muscles, he joined in the assembly work himself.
"Fueeee!?"
Jin, who had started long after her, somehow managed to assemble as many units as she had in no time, and then...
(Ah, that's right. This is just how Jin-sama is...)
Marikka completely threw in the towel. All the assembly work was finished before dinner.
"Good. We'll handle the control systems tomorrow."
Jin was satisfied with having reached a natural stopping point.
"Thanks, Marikka. You were a big help."
"...I-I'm exhausted."
Even Marikka seemed overwhelmed by Jin's relentless pace.
"...But it really is fun, doing this kind of thing."
She looked back nostalgically on the days when she had first started learning magi-craft from Jin.
＊ ＊ ＊
"Well, let's have a bath before dinner," Jin announced upon returning to the House.
"Yay!"
"I've been looking forward to it."
"So happy."
Not just Rubina, but Neige and Rouge as well had taken a complete liking to bathing.
(I suppose I'll have to build a bath for the Elder's house too,) Jin thought to himself.