"Father, what about me?"

The question was whether or not Reiko would have to follow him, just as she had done with the demon tribe.

"I want Reiko to help me with various things here ......."

"I don't want to leave your father's side."

The old man's mobile terminal, <, would be enough on his own, but it would be better to have a support person.

"All right, I will ask Anne to go this time.

Jin calls Ann.

"Goshujin-sama, you wanted to see me?

Ann, I would like Lao Tzu and Ann to go to Ismar this time.

"Yes, I'll leave it to you."

Jin then told Ann about the details of his plan. Lao Tzu supplemented him and Ann had enough prior knowledge of the plan.

* * * *

After Lao Tzu and Ann departed at the warp gate, Reiko asked Jin, "Father, what are you going to do?

"Father, what is it that you want to do?"

"Oh, after Hanna goes to bed, I will gather the main people and explain it to them.

The time difference between Leusert, the capital of the Shoro Kingdom, where Hanna is currently located, and Horai Island is about 5 hours and 20 minutes. Hanna usually wakes up around 6:00 a.m.

If it is midnight in Leusert, it is 5:20 a.m. in Horai Island.

"Meet Jin's family at 3:00 a.m. Horai Island time.

So, Reinhard, Erza, and Saki answered Jin's call.

Toa and Stearina had been invited to the residence of the Marquis Theoderic and were not allowed to leave.

In addition, Meane, Vivian, and Bertsch did not participate in the meeting since it was going to be a purely theoretical discussion.

"Well, the reason I asked you all to gather here is to talk about a theory I came across the other day.

It was still midnight in the Shoro Kingdom, and Jin began to speak, rubbing his eyes a little sleepily.

"First of all, I think you know about the Magijet Engine that I have developed.

All three present nodded their heads in affirmation.

"I think you also know that this is a configuration of wind magic without the part to counteract the recoil."

Normal wind magic is designed to cancel out the recoil that would otherwise be applied to the performer. Therefore, no matter how strong the wind is, it does not affect the magician at all.

If you stop the << canceling the recoil>, there will naturally be a recoil in the wind magic. This was used to propel the <.

Reinhardt and Erza immediately nodded their heads. Saki also seemed to understand this part of the story, and nodded her head, a little puzzled.

"Now, here's the main question. So, what would happen if we tried to prevent wind from being generated?"

"Huh?　...... I see!　There would be no wind, but only the force to counteract the recoil?"

Reinhard was the first to answer.

"Correct, Reinhard. Let's call it ."

"...... What kind of power is that?"

"No, no, can you just take that power out?"

Elsa and Saki asked.

"That's what we're going to examine.

Jin answered seriously.

"Well, that would be a big step forward!

It could be a revolutionary step forward.

"We have some idea of what it could be through preliminary experiments. Let me explain it to you first."

Jin took out a small magi crystal.

"This is a magical tool that generates directional gravity magic.

After explaining this, he chanted <> to generate gravity.

"This generates gravity of 1G upward. In other words, this is how ......"

Jin picked up a pebble and released his hand on the magecrystal. The pebble does not fall to the floor but floats in the air.

"I see, so it cancels gravity."

Reinhardt said with a satisfied look on his face.

"Yes. So, what if we do this?"

Jin turned the magecrystal 90 degrees to the side, picked up the pebble in the direction he was facing, and released it. Then, the pebble was thrown out diagonally to the side, and fell to the floor pulled by the gravity.

"Hmm, it means that the pebble flew in the direction of the combined force of gravity and the magic tool.

"I'm beginning to understand, Jin. The power to cancel the recoil of wind magic is the same as gravity magic, isn't it?"

Saki spoke up. Jin shook his head.

"That's what I thought too. But it seems that they are not the same thing.

"What?　What do you mean?

"I mean, if that's the case, then the effect of gravity magic should not only affect the magician who casts wind magic, but also farther away from him, right?

"Let's see, ......."

Saki, who had not understood Jin's explanation well, thought for a moment, letting her eyes wander in the air as she tried to digest what he had said.

At that moment, Erza spoke up.

"If it was the same as gravity, it would affect us much farther. But in reality, the power to eliminate the recoil is only applied to the magician. Is that right?"

"That's right, Elsa. That's what I'm ...... having trouble with."

Jin explained once again that gravity magic and ......<> have a different range of effect.

"I think that's why the mana consumed is also very different. Gravity magic consumes 1000 times more mana.

"I see, so that's why Jin is so concerned about this ."

The 1000-fold difference in magical power is significant. Reinhardt seemed to understand why Jin was trying so hard.

"I think the difference in the fuel consumption of magic power has something to do with the area of effect, doesn't it?"

Saki said, finally coming to a conclusion.

Gravity magic has its effect on a straight line extending from the point of origin, while <> has its effect only on the magician. The range of effect is too different.

"Yes, I'm almost sure of that.

Jin agrees.

"...... Jin, what kind of power is anyway?"

Erza asked the question that could be said to be the root of this story. Jin, as expected, is also silent.

"Well, ...... I don't know much about it myself."

Einstein's general theory of relativity explains that the gravitational field is the distortion of space-time itself. Jin knew this, since it was mentioned on TV, in science magazines, and even in science fiction novels and animations.

However, what one knows is not the same as what one understands.

"In this world where there are forces such as free magical elements (ether) and magical power that do not exist in my world, I am sure that a new theory will be necessary.

Finally, Jin had no choice but to say that he honestly did not know.

"The theory is a theory, can we make use of its <?　I'm sure Jin has an idea of what he's talking about. ......

"No, I'm stuck in the middle."

"Really?　Jin, I'd like to hear more about it.

"Me too."

Both Reinhardt and Erza looked at Jin with curious eyes.

"Of course. That's what I was planning to do today.

Jin then took out another Magi Crystal.

"This is a prototype of the recoil elimination magic. But it is a failure.

"What?　Let me see."

Jin shot the magi crystal at Reinhardt.

"Thank you. ...... hmm?

Reinhardt received the Magi Crystal and immediately began to analyze the Magi Formula that was written on it.

"Well, this is ......."

The basic formula is wind magic <. From there, if the magic formula (Magi Formula) that was supposed to make the wind blow was removed, theoretically <> was supposed to remain. .......

"It doesn't work."

Jin said with a face as if he was biting a bitter bug.

"What?"

"......It's probably only magic that works to counteract <>, that is, magic that works to counteract <>, but it won't work without <>, that is, without the wind."

Saki and Reinhard nodded at Jin's guess.

"I see... ......... so it's a result of a cause..."

"So you can eliminate the <>, but it's difficult even for Jin to take out the <> alone. ......

At that moment, Erza, who had been thinking deeply, suddenly spoke up as if an idea had just occurred to her.

"How does the <> cancel out a <> equal to the magnitude of the <>?"

"Huh?"

"If you get some information from somewhere and decide the size of the based on it, there will inevitably be a , I think."

Erza's comment made Jin, Reinhardt, and Saki realize that what she was talking about was the key to the problem.

As soon as the magic is activated, the recoil is canceled without a moment's delay. How is this possible?

"That's what I can't figure out for the life of me."

Jin's voice sounded frustrated.