Jin puts off naming the island and analyzes the <> at the <>.

Jin and Reiko are working on a submarine that looks like an origin submarine, and the <> are working on a submarine that looks like a > design.

"I knew it, this is a golem-like submarine."

"Father, you mean it has a control core, and instead of limbs, it has eight wings and propulsion systems, right?"

"That's right."

If you imagine the movement of this <>, it is a radio-controlled airplane, or a drone.

Controlling the propulsion system and the eight underwater wings would require nine channels.

This is a little too much for a human to control. This is a mechanism unique to a golem brain, or a .

"This propulsion system is interesting. ......"

"Father, it's a bit complicated and difficult to understand. ......"

< technology, even Jin was taking four to five times longer than usual to analyze it, so it was no wonder that Reiko found it <.

"Maybe so. I understood what they were doing fairly quickly, but it took me a while to figure out how they were doing it.

Jin explained to Reiko what he had learned from his investigation.

* * * *

After finishing the rough analysis, Jin and decided to exchange information.

"The that Reiko and I investigated was an interesting propulsion system."

Jin began to explain, careful to choose his words carefully, as if confirming what he had just said.

The words came out easily since he had just explained it to Reiko.

"The system was designed to be able to operate even in areas where the concentration of was low at that time in the southern hemisphere ....... The most important of these was the propulsion system."

"Hmm, that makes sense."

"According to my analysis, the propulsion is similar to water magic.

It is a magic that pushes the target with a stream of water. It is generally said to be of intermediate level.

The target is the submarine itself.

If you use it underwater, it will be very advantageous in terms of quietness. After all, there are no mechanical parts, and the drive system does not generate any jet noise.

"However, I estimate that the Magi Formula is 40% more efficient than anything known today, and produces a power equivalent to a torrent of water.

"Hmm, I see."

"The eight hydrofoils also allow for more efficient attitude control, and they are also very quiet. If it had been deployed in actual combat, it would have posed quite a threat, wouldn't it?

"Indeed. I think your analysis is correct and your judgment is also correct."

< also agreed with Jin's judgment. He then states his findings.

"The submarine we analyzed seems to be a prototype. The one that used or tried to use as the main submarine in this base is the one Jin-dono is looking at."

< seems to have been used to examine its behavior underwater and how it malfunctions.

But for the , it was interesting.

"One of the vessels here has left traces of its <>. Apparently, they had boarded the ship once or twice and enjoyed an undersea excursion by themselves.

<, who is a created by the , seems to be really happy to touch the things they left behind.

Jin could understand such a feeling, so he listened silently as the <> talked happily.

Then, when the <> had finished, Jin returned to the story.

"...... Then, after all, was this submarine used in a war between factions?"

"Well, that point is still ambiguous. Was it a struggle or a performance contest? ...... I think we can find out by examining the facilities on this island."

"Will it, ......?"

"Now that we have a better idea of what a submarine is, perhaps we should examine that first."

"Oh, yes. Can you help us with that?

"Of course.

Thus, Jin and decided to finish the investigation of the <> located at the > first.

* * * * * *

This facility was a simple one, and there was no control magic brain installed.

Instead, there were 10 golems for security and 10 golems for maintenance, and they seemed to be responsible for the maintenance of the facility.

"It hasn't been that long since all functions were shut down, has it?"

"Yes, ...... it's been about 30 years, I'd say."

It seems that all 20 of them stopped working about 30 years ago.

"So ...... this is ....... Hmm, Jin-dono, it seems that the purpose of this facility's existence is more like than .

"Is that so?"

"Yes. When it was first built, it was used to fight other factions as a means of final decision during factional conflicts, but in later years, when each faction's sphere of influence had been established and the population was still decreasing, it seemed to be used for mere <>." ......

"I don't know," he said.

"And that fighting didn't seem to go as far as complete destruction in the beginning, but once it shifted to entertainment, no such consideration seems to have been taken into account at all."

"......"

"Maybe they wanted more stimulation, or maybe they had other intentions, I don't know."

No, thank you.

Jin thanked the .

It seems that the s were looking for excitement in proxy battles, and this was escalating.

Jin thought of this and put on a scowl,

(I don't think so, but they might have been enjoying making automata and golems fight.

(I don't think so, but maybe they were having fun by letting automata and golems fight each other.

* * * * *

< was finished in 10 minutes.

< had read out.

Most of the information was the history of the use of this facility. According to the report, the facility has been used about 500 times in the past 5,000 years.

As it was now around 11:30 a.m., we returned to Horai Island to have lunch with the members of the who had also returned to Horai Island.

The menu was ...... kama-age udon. I put whatever condiments I wanted, such as chopped green onion, fried egg, and shichimi (seven spice) peppercorns.

"It's a little cooler today, isn't it?

"Yes, it is. But it's not as warm as hot udon, so it's just right.

"Freshly made udon tastes good, doesn't it?

"It's firm and slippery. ......

"The dipping sauce is delicious, too.

The udon noodles were well received.

And then there were Neige and Rouge,

"What is this?　It's delicious!

"It's really delicious, isn't it?

They seemed to be satisfied.

* * * * * * * * * * * * * *

After that, Jin and his friends were chatting leisurely over a cup of tea.

Then, Reinhardt asked, "How is Jin D?

"How is Jin D doing?

"Oh, I haven't heard yet."

When he was absorbed in the investigation of the submarine, he did not care about it, but when he was asked about it, he suddenly became curious about it.

"How are you doing, old man?"

The old man was asked by Jin to give an interim report.