The engagement ceremony is over without a hitch, and Jin returns to Reuthert's house. That night was the first time in a long time that he took it easy.

As one would expect, being at the home of one's fiancee's parents is a nerve-wracking experience.

The next day, the 27th.

Jin finally moves to Horai Island with Erza to start the car project.

* * * *

At the research institute on Horai Island and Jin's workshop, Jin first began to think about the outline of the project.

But first, he got stuck there.

"Hmmm, what should I do ......?"

"Brother Jin, what's wrong?"

Unusually, Jin seemed to be troubled, so Erza, curious, called out to him.

"Oh, Elsa. I was just thinking about cars. Would you listen to ......?"

"Yes."

Sometimes, when you are lost in thought, having someone listen to you can help you find a new path.

Elsa decided to sit opposite Jin and listen to him.

"First of all, let's start from the premise that you have <>, right?"

"Yes.

"That's the one whose appearance doesn't match its contents, right?"

Erza agrees.

"And the . That was also a ship that was built with a bind on it.

"Yeah."

"...... and I'm thinking of making it a car, too, with such bindings, so that the outside doesn't match the inside."

"Yeah, I agree. I think it's a good idea. But is that what's bothering you?"

Elsa didn't know what was bothering her.

"Yeah, that's why I'm preamble. I gave out hot air balloons for Conlon 2, and I thought it would be a good idea to do the same for this one."

"You're giving away cars?"

But Jin shook his head.

"That's what I'm struggling with. At the moment, we have two choices: <> or <>. ......

Then Reiko came in with a bottle of Citran juice.

"Father, it's not good for your health to be so hard on yourself. Please make yourself at home.

"Yes, thank you, Reiko."

There was enough juice for both of them, so Elsa joined them.

"It's ...... delicious. Can I tell you what I think of ......?"

"Of course.

"Of course." "I think it's enough that we provide the engine."

Golem itself is an existing technology, and in the Kingdom of Elias, the Arrow is pedaled to create rotational motion.

It would not be surprising if someone develops a golem engine," Elsa summarized.

"I see. That's one way to think about it. ......"

Jin nodded in agreement. Erza finished her Citran juice and said what she remembered.

"By the way, Jin's horse-drawn carriage, didn't it run without a golem horse, too?"

"Eh?　Ah, ah ...... that's right, that's right."

"What's wrong with my brother Jin is that he just keeps on making things after he's made them.

"Hmmm, I can't argue with that because I know exactly what he's talking about. ......"

Jin also drank up his Citran juice and showed a wry smile.

"But I guess so,...... horse-drawn carriages,...... yeah, I think it would be a good idea to try to make it a classic car in terms of design."

Jin has finally learned that if you make something that is too far from the standard of this world in terms of design, it will be difficult to use.

"Well, it doesn't have to fly, you know."

Jin had a feeling that he had seen such a Western movie in the Director's video collection, but this time he decided ......<< at that time>> to make it a legitimate one.

The day was short due to the time difference.

Jin spent the rest of the day working on the concept.

He started work in earnest on the 28th.

"First, we need to build an engine.

Yes.

Yes, I'll leave it to your assistant!

What should we prepare?

Jin started working on the engine with Elsa, Reiko, Edgar, and others.

"Let's start with something we can give to each country as a sample. The material is iron. Carbon steel to be exact.

Reiko prepared about 200 kilograms of iron ingots. To this he added carbon separated from carbon dioxide in the air to make carbon steel with a carbon content of 0.5 percent.

"The configuration is 2 cylinders ......, not a double cylinder."

The structure is based on the idea of pedaling with the legs, so a twin-cylinder is the basic structure.

The hip joint comes to the part that corresponds to the cylinder head of a gasoline engine, the piston is the leg, and the crankshaft is the pedal.

"As for the size, let's say about 50 centimeters in height, where practical.

At this size, it can generate enough power to move a carriage without a reduction gear.

"Magical Muscle" is the standard ......, but that's not good enough. I think I found the leather of the Death Serpent, so let's use that."

This is a demon that I once met in Potrock at the southern tip of the Kingdom of Elias. It sometimes comes to Horai Island and preys on fish in the area.

When they come to Tatsumi Bay, they are exterminated to prevent them from breaching the fishponds where the fish are cultivated. Here are the materials.

To explain the process, Hitoshi first showed me how to make one.

"Okay. Sounds interesting.

"The structure is simple, though. It's heavy, so make sure Edgar holds it securely, okay?

"Yes."

The bearings are made of gunmetal, an alloy of copper with tin and some zinc.

Finally, the control core is set in the top of the cylinder head, where the plugs would be installed in a gasoline engine, and connected to the control conductors to complete the process.

Thus, after about an hour of explanation, the double Golem engine was completed.

"Go ahead, try it out," he said.

"I'll try."

Jin gave guidance on the parts he did not understand or that were difficult, and after about two hours, Erza had also completed the Golem engine.

"It's good.

"Thank you. Thanks to my brother Jin.

Erza said, "It's good work," "Thanks to my brother Jin," etc., but Jin did not help her. Jin did not help her, but only pointed out the problems until the end.

"Less than an hour to go until lunch. We can make another one, right?

"Yes.

So this time, Elsa completed the engine in one hour, half of the previous time, without Jin's help.

In the meantime, Jin had completed three engines. .......

"Looking at my brother Jin, I'm not sure how long I'll be able to keep my confidence ......"

This was Erza's expression of her feelings.

The six completed Golem engines will be presented to the Kingdom of Klein, Franz, Cerroa, Egelea, Elias, and Shoro, respectively.

"Master, I think it's a good idea to give them free of charge.

Lol, a blue-haired automaton who had come to clean the workshop, admonished.

"I would guess that this is a very, very rare and precious magi machine in the world. I think you should demand some kind of compensation.

Brother Jin, I agree.

"I see."

Jin has a problem in accurately estimating the value of his own skills. He was grateful to have that pointed out to him.

"Well, what should we do ......?"

"I don't think you should get paid for it."

"I know that."

Jin did not need Erza to tell him that he had very few opportunities to spend money.

Since the island of Horai is self-sufficient, he can make almost anything he wants. However, if he keeps on hoarding his money, it may chill the economy.

"Materials or ......"

"Well, then, it doesn't matter how much you have. Even if it gets old, its value will not change.

In the event that materials become scarce in the future, they can be released, Erza added.

"Materials that cannot be found on Horai Island would be good too."

Amber and limestone are not produced in Horai Island. However, limestone has been found at the bottom of the sea.

Also, as mentioned before, the production of copper is relatively small. However, there are not many uses for copper and copper alloys, such as copper, brass, bronze, etc., so this is not a problem.

Even the old man joined in.

"Well, I guess so..."

"What about renting a piece of land ...... and doing something with it?"

Elsa suggested with a look as if she had come up with something.

"What is it?"

"Hmm. For example, build a railroad. Build a school."

"Ah, that's a good direction to take. ......"

Jin recalled that there was also a railroad carriage.

His dreams are expanding, but they may not be realized immediately.

The future is still in a fog.