Jin spent the next three days fully immersed in the Kingdom of Elias’s Large Ship Development Project.
Under the official pretext of staying at Marcia's workshop, he used a Warp Gate every evening to return to Kaina Village and spend the night with Elsa and the twins.
Since the time difference between Port Rock Town and Kaina Village was only about twenty minutes, the commute was remarkably easy for him.
June 17.
Tonight, Jin, Elsa, and the twins were staying at Jin Castle. Anne was there as well to provide childcare support.
"Dear, how is the project coming along?"
On the night of his third day on the job, Elsa asked Jin after she had finished putting Yuu and Mio to sleep. Having participated in the development of the Bernstein herself, she was naturally curious.
"Yeah, everyone involved is so motivated that the work is progressing quite quickly."
Progress on projects in this world was remarkably swift, even when compared to the modern Japan Jin had once known. This was partly due to the existence of magic and perhaps a certain national temperament—they were a bit on the impatient side.
There were pros and cons to that trait.
In this instance, Jin viewed it as a positive thing.
"It’s a 50-meter-class vessel, so it isn't far behind the Bernstein in scale."
"Mm."
Elsa brought out a bottle of refined sake from a dedicated cabinet. It was Japanese sake reproduced on Hourai Island—a junmai sake, of course. It was far more sophisticated than the version she had served back in Avalon.
"Will you have some?"
"Ah, yeah. Thanks."
Jin took a wooden guinomi cup from the cupboard. Since it was Japanese sake, he wanted to set the proper mood.
He took a small sip of the sake Elsa poured, rolling it over his tongue to savor the flavor before taking a proper drink.
"Delicious. You’ll have some too, Elsa?"
"Mm, a little."
Elsa didn't have a high tolerance for alcohol, but she enjoyed having a drink for the sake of company. Jin brought out another cup, filled it, and handed it to her.
"Thank you."
With a soft smile, Elsa accepted the cup and took a sip.
"It’s lovely."
The brew fell into the ginjo category, and its refined profile suited Elsa’s palate perfectly.
"……It's so quiet."
"……Mm."
The two of them sat in the bedroom of Jin Castle, comfortably exchanging cups.
The night in Kaina Village deepened in peaceful silence.
＊ ＊ ＊
On June 18, an unexpected interference disrupted the project.
"Armaments, you say?"
The man who had arrived first thing in the morning to make this demand introduced himself as Gaudino Granata, the Marshal of the Royal Navy.
Since he was part of the Royal Navy, Jin assumed he was a military officer directly under the King’s command.
He appeared to be around sixty years old, with white hair and blue eyes. He possessed a sturdy, robust build.
"Our Kingdom of Elias is a maritime nation. We require armed vessels to subjugate magical beasts. I want this ship to be adapted for such purposes as well."
"I was told this was to be a cargo vessel," Jin noted.
"That was the initial concept. But now, we need an armed fleet to intercept the swarms of Death Sea Serpents migrating from the north!" Gaudino asserted.
"But is His Majesty aware of this change?" Sergio, the project leader, asked. "I was under the impression that this project was commissioned by His Majesty personally."
"……Of course he is! Do you doubt the word of the Marshal?"
"No, it’s not that, but..."
At this point, Jin decided to interject.
"Your Excellency, 'armaments' is a broad term. What exactly did you have in mind?"
Depending on the nature of the weapons, the ship's fundamental design might be affected. Conversely, if the equipment had no impact on the structure, the project could proceed as planned.
"Ballistae."
"Ballistae!?"
Jin nearly doubted his ears.
A ballista was essentially a massive crossbow. They were used to fire heavy boulders or sharpened logs.
It was a piece of lost technology that had seen use during the Great Magic War.
Because they were purely physical weapons, they were powerful, but they came with significant drawbacks.
The primary issues in this case were twofold: the massive recoil and the fact that their destructive power depended entirely on the mass of the projectile.
"There are numerous problems with mounting those on a ship," Jin countered.
"Hm? And you are…… I’ve seen your face somewhere before."
"I am Jin Nidou. I joined this development project at the invitation of Marchioness Firenziano."
"Hmph, a foreigner. And what exactly is this Lord Nidou supposed to be teaching us?"
Jin felt a surge of annoyance at the man's dismissive snort, but he kept his expression neutral and began a calm, professional explanation.
"A ballista is, in essence, a giant bow. To be effective, it must fire heavy objects."
"Hmph, I know that well enough without you telling me."
"Then that makes things easier. A ballista capable of piercing a Death Sea Serpent would have to be quite large. Consequently, the recoil would be proportionally massive."
"And?"
"From a tactical standpoint, one would naturally want to mount several along the broadsides, but unfortunately, that is physically impossible."
"Why!"
"If you mount a large-class ballista powerful enough to kill a Death Sea Serpent on the side of the vessel, the recoil from firing it would capsize the ship."
"……"
Gaudino was left speechless.
"The only spots where you could mount them without capsizing would be the bow and the stern, but in that case, you would be limited to only one weapon for your attack."
"Ugh……"
"I ask that you please, at the very least, reconsider the choice of armament."
"……"
Faced with Jin's technical assessment, Gaudino spent a long moment scowling in thought.
"……Very well."
Looking thoroughly disgruntled, he finally yielded to Jin's logic.
"We shall hold off on mounting large-class ballistae."
Though he made the decision grudgingly, the Marshal seemed to have understood the physics behind Jin’s argument. However...
"Magic-based armaments would be acceptable, then?"
It appeared he had no intention of giving up on arming the ships entirely.
"Yes, well… though I imagine it would require incredibly powerful magic to effectively deal with Death Sea Serpents."
"I don't need a lecture on that. I shall return!"
With that parting shot, Gaudino turned and marched away.
"……Sigh."
Jin let out a heavy sigh.
"Jin-san, you really saved us there," Sergio said, offering his thanks. "If we had been forced to mount ballistae, we would have had to scrap the design and start from zero."
"Indeed."
But Jin was feeling a lingering sense of unease.
He couldn't shake the memory of the fleet that had besieged Hourai Island four hundred years in the future—and how closely their silhouettes matched the ships they were designing right now.