After reporting to the branch manager of the Adventurers' Guild, I returned to the mansion. I decided to think about how I could defeat Aqua Dragon with Metis.

　I throw myself down on the living room sofa and stretch out.

I'm tired of ......."

　I let the shadow puppets out of the shadows and set them free. Komugi got on the couch and turned to face me.

'Dr. Grimm, you're going after the Aqua Dragon.

He said, "Yes. If we can defeat the second of the five great dragons, we'll have a solid grade A."

'But there is no current living magic that can reliably defeat the Aqua Dragon.

'Yes, that's right. What kind of magic do you think Métis would like?"

　I asked Metis for ideas.

'The only thing I can think of when it comes to advancing through the water and attacking the enemy is a torpedo.

　I was the same way. But at the speed of a torpedo, it would be repelled by the aquadragon's scales. If that were the case, the torpedo would not be able to exert any additional effect inside the aquadragon's body, and would not be able to inflict any significant damage.

In order to penetrate the Aqua Dragon's scales, we would have to shoot out D-particles with the property at a higher speed than before."

But it's slower in the water."

　When we fought today, when we damaged the aqua dragon, it would attack with a water blade breath with only its mouth on the surface of the sea. If that was Aqua Dragon's way of fighting, we had to hit Aqua Dragon's body underwater to damage it.

What if they attack only the mouth coming out of the sea surface?" Do you just go for the mouth that's out of the water?"

If you aim for the mouth, they will either flee underwater or intercept with their water-blade breath."

　I thought about it with Metis until late at night, but we could not come to a conclusion. The next day, we went to the Adventurers' Guild to see if there was any new information.

　There was very little information about the Aqua Dragon. This was probably because it was the first dragon to appear in the dungeon in Shibushi City.

　Instead, there was a document containing information on Saijo's magical weapon, Durandal. This weapon is said to be the holy sword held by the hero Laurent in the French epic poem "The Song of Laurent.

　The only famous reference to the power of the durandal in "The Song of Roland" is that it sliced a rock in two. However, the dungeon-made Durandal is said to have a special vibration control function and to have caused a mountain to collapse, according to information in the Myths and Legends section of the dungeon archives.

Stolen from its original source, this story is not meant to be on Amazon; report any sightings.

　There are scholars who have studied this particular vibration, and they say that Durandal's vibration does not vibrate the air or water around it, but rather the structure of the space.

What do you mean by 'space vibrates?'"

'Well, I don't really know. I feel like I need someone to tell me."

　I wondered if I could create properties with D-particle primary mutations, but I didn't seem to be able to do it because I don't understand it at all myself.

　I was talking to Métis in the reference room, so I might have looked like a dangerous person mumbling to myself.

　I contacted Murase, a lecturer who teaches magic letters at Hoshi Sei University, and asked him to introduce me to Professor Satonaka, an authority on theoretical physics.

　Incidentally, the study of magic letters has been interrupted because Murase's instructor has become busy. It was planned to resume in the winter.

　After asking Professor Satonaka about his availability, I headed to the university that evening. When he arrived at the laboratory, he found Professor Satonaka waiting for him. Professor Satonaka looks like Hideyo Noguchi with glasses, and he has a genius mind.

　I listened to the professor lecture for three hours, asking about the rudiments of space. My impression was that I didn't understand much even after that much study.

　But Metis seemed to understand to some extent. I promised to donate the money to the professor's lab, then returned to the mansion.

Professor Satonaka's lecture was interesting."

No, I didn't get it. "No, I didn't understand it," he said. There's no way I could understand it."

　＜Having given up on spatial vibration, I decided to create a torpedo-like life magic by setting up a wise man system. I gave up on the idea of penetrating Aqua Dragon's scales, and decided to damage Aqua Dragon by maximizing the explosive power of the .

　The shape formed by the D-particles resembles a torpedo. However, in order to enable multiple activation, it was shaped like a temple bell stretched out. With a maximum width of 30 centimeters and a length of 180 centimeters, it resembles a torpedo or missile.

　This D-particle torpedo is given the characteristics of "detonation," "vector control," and "dispersion suppression. This D-particle torpedo is designed to detonate forward the moment it is hit and stops.

　The reason for choosing the time when it stopped rather than when it felt the impact and was judged to have hit the target was to prevent it from exploding the moment it was released from the air and landed on the water.

　Although not so fast in flight, the destructive power of the explosion was tremendous. The name is "Torpedo Dough," which means torpedo. This magic can be used both in the water and in the air, but it is likely to avoid fire drakes that fly quickly through the air.

　When using this magic to kill an aqua dragon, it will be impossible to kill it with a single blow. It is expected that it will be like giving it a large number of hit bullets and weakening it step by step to finish it off.

　As I was thinking about going to the pay practice field tomorrow to test its power, Métis spoke up.

We may be able to create the characteristics of "spatial vibration.

You know, I could hardly understand it. You can't create something you don't understand.

'I think it's possible if I cooperate.

　Metis' proposal was that Metis would be connected to the sage system in sync with my spirit during the work of creating the properties of the D-particle primary mutation.

　Since Metis can stay in sync with my spirit for only about five minutes, I will have to do the work of creation on my own from the middle of the process, but he says it will be okay if I first give the information about the space that Metis understands to the wise man system.

Are you sure you're okay?"

If it fails, it is only because it cannot create the characteristics of spatial oscillation.

　Then I thought I would give it a try. I took out the "Ring of Pain Reduction" and put it on my finger, and once again started up the wise man system.

　Next, I synchronize my spirit with the Métis. This was no effort on my part, as Metis was attuned to my spirit. However, I could feel that Métis was putting a huge amount of mental energy into tuning me in.

　The moment our minds were in sync, I instructed the sage system to create the characteristics of . I felt the information flow in from the metis, and the sage system received it and began to create the characteristics.

　That intense pain started. It was not as painful as the first time because of the "pain reduction ring," but I had to grit my teeth and endure it. After five minutes, I was out of sync with Metis.

　When the intense pain lasted more than 20 minutes, consciousness faded away.

indistinct

I was worried that I would fail. Fearing that I might fail, I regain my nerve and endure the intense pain. After 30 minutes, I felt like I was about to lose consciousness. At the moment I thought I had failed, the was complete.

Ha ha ha ...... I'm going to throw up."

　I curled up on the couch, looking at the floor and muttering.