On Ars, it was the 30th—the last day of February.
Jin and his companions had been at the Marcia Workshop since early morning. Prince Ernest and Princess Lieschen hadn't arrived yet, as was to be expected at this hour.
“I’ve got to fix Arrow first,” Jin said.
He’d felt guilty for putting it off, but with the victory party the previous night, the repairs had been sidelined until now.
“I’m counting on you, Jin.”
“Yeah, leave it to me.”
Jin laid Arrow on the workbench and commanded her to Stand Still.
Then, with Elsa, Reiko, and Edgar acting as his assistants, he began the Decomposition of Arrow.
While they worked, Lishia and Hanna were given a tour of the workshop by Marcia.
Once Jin had removed the exterior and muscle systems, he performed a check of the skeleton.
“Yeah, the skeleton isn't showing any signs of rattling. The joints are all clear, too.”
“As expected of Jin-nii,” Elsa said.
“Now then...”
A voice suddenly rang out through the workshop.
“Ah! Jin, it’s not fair to start while I’m not here!”
“N-Nest-sama, please, lower your voice a little...”
It was Prince Ernest and Princess Lieschen. Despite it only being 8:00 AM, they had already arrived.
Their only visible attendants were Lotte and Tia. However, Reiko sensed that several other guards were likely stationed nearby, protecting the royals from the shadows.
Prince Ernest strode over to Jin’s side.
“So this is Marcia’s Arrow. She’s like an older sister to my Lotte, isn’t she?” he asked with deep interest.
“That’s one way to look at it,” Jin replied, his hands never stopping.
“Reiko, give me some 64 light silver.”
“Yes, Father.”
“Edgar, hold this part down for me.”
“Yes, Jin-sama.”
With two capable assistants, the work proceeded rapidly.
In no time at all, the left arm was regenerated and the muscle systems were reattached. Jin also checked every joint throughout the body for clearance and made the necessary adjustments.
“It’s impressive every time I see it...” Prince Ernest murmured, captivated by Jin’s efficiency.
“Alright, everything looks good.”
Having finished the full check and moved on to reassembly, Jin finished putting Arrow back together in less than two minutes.
“S-So fast...”
“...”
Prince Ernest could only mutter his surprise, while Princess Lieschen was left speechless.
Jin commanded Arrow to Wake up and asked how she was feeling.
“I am fine, Jin-sama. There are no problems. I will be of even greater service to Marcia-sama than before.”
“That’s good to hear. I’m counting on you....Your Highness, since we’re here, would you like me to check over Lotte and Tia as well? Marcia, is that okay with you?”
“Yeah, of course!” Marcia nodded readily.
Naturally, the two royals weren't about to refuse.
“Eh? A-Ah, yes, please! I would appreciate that!”
“Yes, I ask it of you!!”
And so, borrowing Marcia’s workshop, Jin decided to perform an overhaul on the two of them.
Since Tia’s construction was quite intricate, he asked Elsa to handle her Decomposition.
Within five minutes, both units had been stripped down to their skeletons, and Jin began his inspection.
“The adamantite-coated joints haven't worn down at all. They’re in excellent shape.”
He began reassembling them while once again meticulously adjusting the clearance and balance.
Their muscle systems also appeared to be in perfect condition, showing no signs of overstrain.
However, Jin didn’t intend to simply put them back together as they were.
Originally, both of them used materials from fairly powerful magical beasts for their muscle systems. That meant their power output still had room for growth.
Jin boosted the efficiency of Tia’s ether converter and mana driver, easing the limiters on her magical muscles to match.
With this, her reaction speed would double, and her power output would increase by about 1.5 times.
At the same time, he took this opportunity to upgrade Lotte—who had been using a mana tank specification—to an ether converter and mana driver similar to Tia’s.
“Wow, I can’t even follow what’s happening...”
Prince Ernest let out a sigh of amazement, while Princess Lieschen watched in stunned silence.
Jin then began the final assembly. He left the task of reattaching Tia’s magical skin to Elsa while he handled Lotte’s reassembly himself.
The entire process took about ten minutes.
“How do you feel, Tia, Lotte?” Jin asked as he woke them up.
“I feel wonderful. Thank you very much.”
“I feel even better than before. Thank you.”
Both appeared to be in peak condition.
“That’s that, then. Now, for the real work.”
“Eh?”
Seeing Prince Ernest’s puzzled expression, Jin added, “We’re here to talk about ships, right?”
“Ah, that’s right! I was so mesmerized by your skill that I completely forgot,” Prince Ernest said, scratching his head.
“First, I think it’s important to clarify exactly what you want to know,” Jin said.
Since their time was limited, he wanted to be focused.
“Yeah, I understand that, but... my eyes just keep wandering.”
Prince Ernest’s distraction was understandable. Marcia Workshop was packed with materials, documents, and actual ship components.
“I’ll leave the lesson plan to Jin and Marcia. I can only stay for the morning... well, until 11:00 AM, to be precise. At 11:30, I have a lunch meeting that includes Miss Traine.”
“Understood.”
Prince Ernest laughed, noting that showing appreciation for Miss Traine, who had represented the Kingdom of Egerea, was one of his royal duties.
Despite their busy schedules, Prince Ernest and Princess Lieschen were clearly pushing themselves to make this time.
Jin thought for a moment about the most efficient way to teach them the broad strokes of shipbuilding in such a short window and concluded that starting with the fundamentals was best.
“Alright, let’s begin. First, do you know why a ship floats?”
“Eh? Um, because it’s light?”
“I won’t say that’s wrong, but... let’s start there.”
Jin pulled out an imitation whiteboard made of Ground Spider resin (GSP) that he had gifted to Marcia Workshop and began sketching diagrams on it.
“First, when an object is placed in water, it becomes lighter by the weight of the water it displaces. I want you to remember this as a basic principle. I couldn't explain the physics behind it if you asked, but it's a fundamental truth.”
“Right, I’ve got it.”
“In other words, an object lighter than the weight of the water it displaces will float, and a heavier object will sink. This holds true even for a ship made of iron.”
“Ah, so that’s why the ship I saw at Kunlun Island floats!”
“Exactly.”
“Hmm, so that’s how it works! Until now, I’ve just been building things based on intuition,” Marcia said.
“Eh?”
Jin realized that Marcia and Rodrigo were also listening intently to his lecture.
“What you're saying is very helpful, Jin. Do you mind if we listen in too?”
“Of course not.”
Jin nodded to Marcia and continued his explanation.