"Barrier!"
Seeing the ship falling toward them, Jin instinctively cast a Barrier. Though invisible to the naked eye, the Secret Mobile Unit (SP) guarding Jin and Elsa also deployed their own barriers and drew close to them.
Jin pulled the Air Leichtern magic tool from his pocket, intending to activate it, but at that very moment—
With a deafening boom, the ship that should have crushed them was blasted in the opposite direction.
Wood splinters pattered against the barrier, but they were harmless.
"Wh-What in the world just..."
A pale-faced Eckart spoke in stunned silence.
And for good reason—the forty-meter-long ship had been pulverized beyond recognition.
"Father, are you alright?"
Naturally, it was Reiko’s doing. To protect the group—or more specifically, to protect Jin—she had kicked the falling ship away with nearly her full power.
As a result, the structural timbers, including the central beams that were fifty centimeters square, had been blown apart at the joints. The hull plating that had been attached to only one side was scattered like autumn leaves.
"Yeah, I'm fine. But you certainly didn't hold back, Reiko..."
The ship no longer existed. It was nothing more than a field of rubble. Reiko's single strike had carried enough shock to disintegrate a forty-meter-class vessel, even one still under construction.
"I have also captured the culprit."
"What!?"
"Someone had sabotaged the ship's cradle."
Just as Reiko made her announcement, Neon arrived, dragging an unconscious man behind her.
When Eckart saw the man’s face, his expression shifted from shock to a boiling rage.
"It's him! The site foreman!"
Eckart immediately issued orders to have the matter reported to the town guards.
Once the guards were notified, the bailiff in charge of the town of Koup personally arrived with his men to conduct an inquiry. It was a testament to how highly Eckart was regarded in the region.
Jin and his companions couldn't simply leave while the investigation was underway, so they stayed to provide an explanation at Eckart’s earnest request.
"I see, a friend of Vivian's. Stearena Beta... Wait, that Stearena!?"
Stearena was a celebrity in the Celuroa Kingdom. News of her seeking asylum or defying the nobility had not yet reached this town at the southernmost tip of the kingdom.
Stearena had partially resigned herself to the situation, figuring that while trouble might arise later, she would be long gone from this place by then.
"I don't know which 'that' you mean, but I am Stearena, the magi craftman."
Stearena acted as the spokesperson. After hearing the full account of how they had used their golems and automata to rescue the injured, the bailiff looked satisfied.
"So, you used your own golems and automata to rescue the workers. I see."
As expected of a famous figure, Stearena's testimony was accepted as credible. Jin and the others were relieved when they weren't even asked for their names.
The foreman, who had regained consciousness, confessed during a brief on-the-spot interrogation that he had been bribed by one of Eckart's business rivals.
The rest was a matter for the judiciary.
"Everyone, I apologize for keeping you so late. Please, you must stay the night."
By the time the bailiff and his soldiers led the culprit away, dusk was already settled over the yard. Jin and the others accepted Eckart’s hospitality and decided to stay for the night.
After they had bathed, dinner was served.
True to his word, Eckart had miso soup made with dashi brought out. The chef must have memorized Jin's technique; although it was a miso soup containing leafy vegetables like cabbage, it was now quite delicious.
The rest of the meal consisted of venison steak, grilled dried fish, salad, and fruit. It wasn't extravagant, but the ingredients were of exceptionally high quality.
"...I still think rice is the best pairing for miso soup," Jin murmured.
He simply couldn't keep the thought to himself.
"The 'nogi' harvested in the southern part of the Shouro Empire goes perfectly with this miso soup. You should look into it."
Eckart was overjoyed by the suggestion.
"Is that so! You've taught me yet another wonderful thing; I cannot thank you enough!"
Seeing the merchant’s excitement, Jin felt a little better about the ship's destruction earlier that day. Although the accident wasn't Jin's fault, it was Reiko who had ultimately finished the vessel off.
However, as if reading Jin's mind, Eckart spoke with a reassuring smile.
"Jin-sama, please do not trouble yourself over the ship. In that situation, there was no other choice. It is a shame the vessel was lost, certainly, but if it's broken, we can simply build it again. More importantly, your healing of the injured and the fact that there were no fatalities are far more significant."
"...Thank you. It puts my mind at ease to hear you say that. I also apologize for being so blunt earlier. Please forgive me."
"No, no. It is not limited to miso, but frank opinions are very much appreciated. In fact, I am grateful to have learned the correct way to use the ingredient."
Jin found himself liking Eckart. Because of that, he decided to offer a bit more help.
"...If you don't mind, could you let me see the blueprints for that ship?"
Reinhard's eyes lit up at the suggestion. It was the perfect moment for a magi craft enthusiast to shine.
"Oh, Jin, are you going for it? Let me help too!"
Jin nodded with a smile.
After dinner, Jin and Reinhard were invited to a study to view the blueprints. The ship was planned to be forty meters long and ten meters wide. The height of the hull was six meters, with a total height of twelve meters including the cabins.
"Hmm, impressive."
It was a giant ship that even made Reinhard groan. Vessels of this size simply did not exist in this world, aside from those on Hourai Island.
Meanwhile, Jin voiced a question he had held since seeing the wreck earlier that day.
"What is the power source? How do you intend to move it?"
The propulsion method was not specified in the blueprints.
"...That is a secret among secrets," Eckart said. "It is a revolutionary, unprecedented method devised by my family's personal magi craftman."
Since they were told it was proprietary information, Jin and the others couldn't press any further. They could only speculate that some kind of propulsion system would be attached to a specific step at the stern.
Instead, they focused their advice on the hull and internal structure. Jin didn't interfere with the construction of the keel, as he wasn't well-versed in wooden shipbuilding, but there was one thing that bothered him immensely.
Despite being such a large ship, the design featured a flat bottom.
While a flat bottom was easier to build and made partitioning the interior simpler, a vessel forty meters long would face structural integrity issues on the open sea.
It might be fine on calm water, but the ocean was defined by waves. The hull would be tossed up and down constantly.
If a large wave lifted the bow, the next moment it would fall and crash into the water's surface. With a flat bottom, the shock applied to the hull would be massive.
Therefore, to dissipate that force, a V-bottom hull was the standard.
This was a basic principle of naval architecture Jin had picked up while making ship models. If the structural strength was sufficient, perhaps it wouldn't be an issue, but looking at a ship meant to be made entirely of wood, Jin was worried.
"I see..."
Eckart listened intently to Jin's explanation, his face turning contemplative.
"I understand your point, Jin-san. So, we should either increase the structural strength or change the shape of the bottom to mitigate the impact."
"Exactly."
"Ah, and one more thing from me," Reinhard added. "If you're building a ship this large, you should have many internal partitions and ensure each one can be sealed watertight."
If a leak occurred, containing the water within a few cabins would prevent the entire ship from sinking.
Eckart, a true lover of ships, grasped the logic immediately.
"I see. That is excellent advice. I thank you both."
"We would certainly love to see it when it is finished."
"Haha, when that time comes, I would very much like you both to be my first passengers."
With that, Jin and Reinhard concluded the discussion and retired to their guest rooms.
"...Jin, what's your guess?" Reinhard asked once they were alone, still curious about the propulsion system.
"I thought it might be a method of using oars or paddles sticking out from the sides, but the blueprints didn't show any openings for them."
That was the method used for ten-meter-class ships, like patrol boats.
"Yeah. There were no holes in the side plating. The thing that gets me is that step at the stern."
"Right. Since there's no screw propulsion, I think something is meant to be attached there externally. That limits the possibilities."
"Here's a thought... just maybe. What if they attached something like the lower half of Lorelei there?"
Reinhard's suggestion was out of the blue, but after a moment of thought, Jin didn't think it was such a strange idea.
"I see. Mimicking a fish's tail fin?"
"Exactly. It's not a bad way to generate thrust."
Since it was a drive system based on magi-engineering rather than modern science, they both agreed that such a biological mimicry might just be what the merchant had planned.