Chapter 10
“How did you do that?”
Akion, who had showcased a manly Water Style in a place without magic.
After nearby lords clamored for him to supply them with pumps,
and after sending back the mages from the Mage Tower who charged in drooling, shouting, ‘The Tower Master resides in the workshop, so it’s a Mage Tower too!’
“I said, how did you use water magic?”
“I didn’t.”
A magic absolutist had barged into the workshop.
Her name was Hermione Enersis, and she was his half-sister.
“There’s no way. Do you really think you can use a stream that powerful without magic?”
“Sister, alchemy is magic too.”
“Liar.”
Akion recalled the seventeen years of memories he had kept buried in a corner of his mind.
Hermione Enersis. Nineteen years old this year.
A first-year student in the Academy’s Department of Magic, she had entered as the top student and was a genius of water and ice magic, the pride of the Blue Mage Tower.
“You can’t even understand magic. There’s no way you could understand alchemy.”
She was the third of the three children born to Lucretia,
and a magic absolutist who believed everything was possible through magic.
She was also the one who had bullied Akion the most of the three siblings.
If he had to pick one incident, perhaps it was when he was ten. She locked him in the family warehouse and hid the key so no one could find him.
“But, Sister. I did it, and you’re simply refusing to believe me.”
“Haa…?”
It was only after three days that Akion was discovered.
And Hermione had laughed at him in his disheveled state.
Akion still remembered it vividly.
“Akion Enersis. Are you out of your mind?”
“Yes. Is there a problem?”
Now that he had awakened to his memories of reincarnation, he could look back on it as a third party—but even so, Akion’s displeasure did not disappear.
- Vrrr!
“I heard that Father dotes on you, but it seems you’ve forgotten how great the difference between you and me is.”
Just as in the past, she was trying to create a large droplet of water and place it over his head.
It was a method Hermione often used when bullying Akion.
Of course, Hermione knew where to draw the line.
Akion had clearly given up his claim to the countship. And yet he was still favored by the count?
That meant there was something going on, and she had enough cunning not to cross that line.
“Should I educate you like I did in the old days? Tell me obediently who helped you.”
However, she was certain that Akion had received help from someone.
In other words, she was a young lady who still believed in the theory that Akion was incompetent.
“Sigh. Sister, please.”
“I’m the one asking you. Don’t lie. Tell me who helped you.”
Perhaps that was why, just as when she had bullied him in the past, she considered herself to be in the superior position.
Akion found this side of his sister truly unpleasant.
How could she still threaten him by bringing up the days when she bullied him, even after growing older?
“So be honest, Akion. What trick did you pull to use water magic when you’re as talentless as you are?”
Akion let out a deep sigh and rolled up his sleeves.
“Sister.”
“Hm?”
And with all his strength,
- Smack! Crash!
he slapped Hermione across the cheek.
Even a mage was an ordinary person if they did not use physical enhancement magic.
Seated on a chair, she went tumbling across the floor.
“Huh…?”
Hermione, suddenly slammed into the workshop floor, was bewildered.
She touched her burning cheek and tried to recall what had happened.
In other words, the youngest half-brother she had ignored and looked down on had…
“Sister. You still haven’t fixed that jealous temper of yours?”
“Y-you…!”
“If you thought I would endure being insulted like I did in the past… you were mistaken, Sister.”
He had slapped the cheek of Hermione, who would one day become a great archmage?
- Vroooom!!!
The area in front of the workshop instantly roiled with mana.
Akion and Hermione’s hair whipped in the wind.
“You.”
The absurdly powerful mana output granted by the Enersis bloodline.
A storm of mana was sucked into Hermione, and ice spears blossomed all around her.
“May I take this as a challenge to a duel?”
“Think whatever you like. Didn’t you do that in the past?”
Seeing that there were exactly four ice spears, she had apparently recalled the times she had tied up Akion’s limbs and beaten him.
Dwelling on that inference, Akion merely let out a leisurely sigh.
“More importantly, Sister.”
“Yes. Speak. I’m merciful, so I’ll hear your last words before freezing your vocal cords.”
The reason Akion had dared to stand up to his sister despite being unable to use magic was that he had something to rely on.
“Someone has been watching this situation from earlier.”
“Hm?”
From the very beginning, the Tower Master, who cared for Akion, had been glaring at his sister.
- Clang!
“Eeeeeek!!”
The four ice spears shattered into pieces, and Hermione was grabbed by the nape of her neck.
“L-let go!”
She tried to resist, but whenever she summoned mana, it was forcibly suppressed.
An existence capable of controlling even her opponent’s mana! Could such a being really exist?
“Who is this brat? How dare she try to attack my disciple?”
There was. The Ridasid Tower Master—a monster called a dragon.
When Hermione saw the Tower Master’s dragon horns, all the color drained from her face.
“She’s my half-sister. And when did I become your disciple, Tower Master?”
“It is a foregone conclusion, so you are my disciple.”
More importantly, how long was Akion supposed to tolerate the Tower Master’s unreasonable insistence?
Since he heard it every day, it had started to seem cute to Akion.
“I watched from the beginning, but I’ll ask again. Why did you quarrel with your sister?”
“She told me, ‘If you can’t use magic, crawl on your own,’ so I slapped her.”
“Oh. Akion. I never knew you could lose your temper.”
“I’ve lost it at you a few times too. Anyway, after being bullied for seventeen years, this little slap is acceptable, isn’t it?”
The Tower Master had learned from Goldie what sort of life Akion had led.
Seventeen years was a short time for a dragon, but she knew that even a single year was enough for the power of a bond to act strongly.
“I see. Akion.”
“Yes.”
“Would you consider becoming my disciple in exchange for letting me deal with your sister?”
If so, perhaps she could accept Akion as her disciple in exchange for ‘dealing with’ his sister.
As the Tower Master seriously pondered the matter, Akion noticed and let out a deep sigh.
“No thanks. Seeing her like that, engaging with her seems even more foolish.”
“Hmm. I thought you hated her.”
“No, Tower Master. Look at what state my idiot sister is in right now.”
“Hm?”
In truth, there was another reason for his sigh.
- Trickle… drip, drip.
The Hermione dangling from her hand was foaming at the mouth, with a little yellow liquid seeping out from beneath her dress.
On top of that, people from the workshop had gathered nearby after hearing the commotion.
“Hmm. It seems I leaked killing intent without realizing it.”
“Well, whatever. Let’s call someone to clean this up. How much does deodorizing magic cost again…?”
From Akion’s perspective, well, it was satisfying in its own way.
*
Two days later.
- Boom!
“W-what was that!”
“Did something explode? Did an alchemical ingredient blow up?!”
The craftsmen bustled about, trying to determine what had caused the enormous explosion that rang out from inside the workshop.
“Tell me.”
The culprit was none other than Hermione Enersis. She had slammed her head into the workshop floor hard enough to make a sound.
The proud sister who had immediately fainted and even wet herself in the face of the Tower Master’s killing intent, then secluded herself for about a day out of shame after the servants washed her unconscious body.
“Teach me magi-engineering too.”
“I understand that Third Sister is desperate.”
She had crawled back into the workshop again!
Of course, she was keeping a low profile this time. She was asking him to teach her engineering… so why did she insist on calling it magi-engineering, for crying out loud?
Akion sighed and crouched down in front of her.
“However, I have no desire to show you any kindness.”
“Nngh….”
Even if he recalled his memories of reincarnation, could seventeen years of hatred disappear so quickly?
That was why Akion had slapped his sister. Simply seeing things from a third party’s perspective would not sift away his feelings of hatred.
But!!
“Y-yes. I’ll do anything you tell me! So teach me that magi-engineering too!”
“Not magi-engineering. Engineering.”
A single sentence echoed in Akion’s ears!!
‘I’ll do anything you tell me!’
“But, haha. You said you’d do as you were told?”
How sweet that one sentence was!
Akion understood the feelings of a wicked professor.
‘Professor, so this is how you felt when I said I wanted to publish a paper based on your doctoral dissertation and was interested in joining your lab.’
He must not become like that person… but to Akion, his half-sister’s request to enter graduate school—in other words, her declaration to become a slave—was truly ecstatic.
He could get a research slave to work for the rest of her life in exchange for seventeen years of hatred?
That was enough for him to bury his resentment.
“Haha, since you’re so passionate, I suppose I should let go of my anger as well. Welcome, research slave—or rather, undergraduate in the Department of Magi-Engineering!”
“H-huh? So you’re accepting me for now?”
“Of course! Seventeen years of ill feelings? I can set them aside for a while for someone who wants to study the same field!”
And so, Hermione dove headfirst into his clutches of her own accord.
“Th-thank you. Even though I bullied you so terribly, you’re willing to accept me like this….”
She was simply happy that Akion had accepted her as a fellow mage.
*
“The pressure’s high here.”
Hermione Enersis’s talent lay in water and ice magic, but when Akion examined her, he found something even better.
“As expected, it’s a problem with the discharge section…. Should we give this a little more curvature?”
“Then we’d have to redesign the external framework.”
“That’s still better than fatigue failure. Sister, what about this side? Compared to the spot we checked earlier?”
“Yeah, it’s about two-thirds as high here.”
She possessed an overwhelming ability to perceive fluids.
What this meant was that she could sense everything about the flow of water.
Where it pooled, where the water pressure was strong, and where it swirled. Everything!
Akion was incredibly happy that he had acquired a fluid simulation program.
“I’ll explain Bernoulli’s principle.”
Of course, this was not free.
She had said she would do anything, but could he really just whip a slave and call it a day?
“It’s a basic principle of fluid mechanics, and you can think of it as the fluid version of the law of conservation of energy I taught you a few days ago. The Bernoulli equation is derived from the Navier–Stokes equations using vector calculus—”
“Wow….”
He bestowed his knowledge of fluid mechanics upon her.
Before that, he had already packed her head full of basic scientific knowledge.
Countless established laws poured from Akion’s mouth, and Hermione was too busy transcribing them to do anything else—but she was having the time of her life.
“Akion, how do you know all of this?”
All of it fit perfectly with the magical theories she already knew!
The moment Hermione understood these laws of nature, she felt as if her eyes had been opened.
Her past self seemed so blind by comparison.
“Because I’m a genius.”
“Tch. Aren’t you something?”
Of course, this knowledge was an aggregate of data studied by countless scientists.
Akion merely remembered it based on the knowledge from his past life.
‘Please forgive me just this once, seniors.’
Akion apologized inwardly to all the senior scientists.
“Ahem. So that’s how it is.”
“Goldie doesn’t quite understand this. Could you explain it to me?”
The Tower Master and Goldie were listening alongside them.
He had sent both of them home, but they had snuck into his lecture and were now shamelessly eavesdropping.
“Why are Goldie and the Tower Master listening?”
“Goldie attends to Young Master’s needs!”
“I am his patron.”
“Good grief.”
The two of them came up with reasons of their own, and Akion let out a hollow laugh.
Still, Akion was quite pleased that there were people who loved engineering this much.
“That’s all for today.”
“Ah?! No! Teach us more!”
“I concur! Why are you stopping here?!”
“Eee! Young Master! Please teach us more!”
“All three of you, summarize what you learned today.”
Of course, what made him happiest was that Hermione had become his lab slave.
*
Early autumn.
It was one week before Hermione would return to the Academy after her two-month vacation.
- Rumble rumble rumble!
On one side of the Enersis estate, a turbine pump had been installed in a once-unused lot.
Akion’s workshop stood on that lot.
- Hummmmmm….
- Whoooosh!
Water was drawn from the river through pipes leading to the estate, then sent by the turbine pump to the roof of the workshop building.
The clean water transported there was neatly stored in a water tank treated against corrosion and moisture.
- Click!
- Whoooosh~!
The stored water flowed wherever it was needed inside the workshop,
- Click.
When Akion turned off the faucet, no more water came out.
“Phew.”
One of the grand projects born from the development of the turbine pump—the introduction of a modern waterworks system.
After countless guild craftsmen and Hermione had poured out their blood, sweat, and tears….
“Now this is a bathroom.”
It had been installed in his workshop as a trial run.