"Netros, are you okay?"
As Sion asked with concern, Netros pushed himself up from the floor and nodded.
"I am fine. However, it was my own incompetence that allowed Lady Istalis to be subjected to such a state."
"What happened?"
Netros shook his head slowly. "I... I cannot say. Please, just consider that she was subjected to treatment that defies all description."
"..."
Jin tapped Sion on the shoulder. "You should probably stop there."
Netros stared at Jin. "And who might you be?" he asked.
"This is Jin. He's the one who saved Lucas and me," Sion explained briefly. "And when I told him how you and my sister had been tricked and taken prisoner, I asked him to help rescue you."
"I see. Jin-dono, you have my gratitude."
Having just endured such an ordeal, Netros still looked as though he couldn't fully trust a human, but since Sion was the one vouching for him, he seemed to accept it for the time being.
"He's even sharing food with us! And more importantly, he's a Magi Craft Meister! I'm sure he can help us."
"What? A Magi Craft Meister, you say?"
It appeared that Netros was also familiar with the title. "That great... no, surely he cannot be that person?"
"Of course not. Humans live much shorter lives than we do. He says he's the second generation....Right, Jin?"
The last remark was directed at Jin, who gave a firm nod.
"Yeah. I am the 2nd Generation Magi Craft Meister."
"I see... After what we've been through, I find it hard to trust humanity. But if he is a Magi Craft Meister... perhaps he can be trusted."
For the demon race, the title of Magi Craft Meister seemed to hold a special, profound significance. Jin was curious about it, but he decided that now was not the time to pry.
"...The question is, what should we do about Istalis?"
She had clearly suffered immense trauma. The moment she regained consciousness, she would likely fall into a state of hysteria again.
Sion looked equally worried. She had forgotten all the questions she wanted to ask—like why her sister had come to the human world without her knowledge—and simply wore a troubled expression.
"They say time heals all wounds, but..." Jin muttered to himself. Then, he found a spark of an idea in his own words. "I've got it... Sion, stay with your sister. I'm going to step away for a moment."
"Eh? Okay. You have a plan, don't you?"
"Yeah, but I don't know if it'll work. Don't get your hopes up too high while you wait."
Jin left the room and immediately traveled to Hourai Island.
"Laojun, what do you think?"
"My Lord's plan is feasible. However, there is one problem that must be solved."
"Is it... that?"
"Yes. Given that Trans Info was ineffective, she likely has a high resistance to mental magic."
"But if her physical composition is no different from a human's, why is that?"
"I do not know. We have no samples to analyze."
"If we had one... could we manage it?"
"The probability would increase significantly."
After consulting with Laojun, Jin returned to Nidou Castle to speak with Sion. In the guest room, Istalis still lay unconscious.
"Jin, how was it?"
"Well, I can't guarantee it'll be perfect, but I've found a method that might work."
"What kind of method?"
"Before I explain, let me ask: do your people have magic to erase memories?"
"Eh?...There should be, yes....Wait! You're planning to erase my sister's memories?"
Indeed, the treatment Jin had devised was to use the forbidden spell Amnesia to erase her memories of the torture. Amnesia could only erase memories sequentially, starting from the most recent and going back; it couldn't selectively target specific events.
Fortunately, she had likely been unconscious for most of the time between her capture and rescue, meaning there was a low risk of creating major discrepancies in her memory.
"I see. If you erase the memory of the torture, she won't fall into that frenzy again."
Sion and Netros seemed to understand the logic. Lucas, on the other hand, looked a bit lost.
"Sion, what do you think?"
"..."
Sion understood the inherent danger of tampering with memories. What if it failed? Or what if Jin intentionally erased more than just the torture? There was no end to the suspicion if she allowed herself to doubt him.
Netros, for his part, deferred the decision to Sion, the princess's sister.
"...I've decided. Jin, please. Erase my sister's memories of the torture."
"Understood."
Jin nodded firmly and ordered Nurse Alpha and Beta to carry Istalis out on a stretcher.
"I can't perform the treatment here, so I'm taking her to my secret base. I'll be back soon, so don't worry."
"Right. At this point, I have to leave everything to you, Jin."
"I intend to live up to that trust."
In the command room beneath Hourai Island, Istalis was laid upon a bed.
"Laojun, it's up to you."
"Understood....Commencing."
Laojun's mobile terminal, Laozi, placed his right palm on Istalis's forehead.
"Trans Info... As expected, it is ineffective."
"Hmm, this is tricky. What could it be...?" Jin fell deep into thought. "Thought... spirit... brainwaves... Brainwaves? Laojun, you have data from when the demons used magic, right?"
"Yes, several samples."
"Check the magic patterns. Specifically the frequency."
"Understood. Collating data... I see. This is..."
"How is it?"
"Yes, the frequency is extremely high."
The answer was exactly what Jin had suspected.
"I thought so. It was just a hunch, but I was right. In a demon's magic pattern, the frequency is unusually high. It's an order of magnitude higher than a human's."
"I see. If that is the case, it stands to reason that conventional human spells would fail to register correctly."
"Exactly. Let's find the optimal frequency."
According to the Nyquist theorem, to sample a waveform accurately, the sampling frequency must be more than twice the highest frequency component of the signal's bandwidth. For example, music for CDs is sampled at 44.1 kHz to cover the human audible range of up to 20 kHz.
In the case of the demon race, because the frequency of their magic and spirit waves was higher than that of humans, magic designed for humans couldn't read them correctly. Following this logic, Laojun performed Trans Info several times and determined the optimal magic pattern for access.
"I have determined it. The probability of success is now very high."
"Great."
"However, when altering memories, we must be careful about how far back to go."
"I can get a rough estimate from Netros. The real question is whether we can specify the date and time and process it accurately."
"That should not be an issue. Based on data from the prisoners at the Inado Mine, the margin of error should be no more than an hour."
When the prisoners from the Inado Mine had attacked Kaina Village as part of Earl Walter's conspiracy, Jin had neutralized them and erased their memories of how they were captured. Using that data as a benchmark, Jin planned to erase Istalis's memories up until the point she was captured.
"Will you confirm the timing?"
"Understood."
Jin returned briefly to Nidou Castle to consult with Netros.
"She was captured on August 4th."
"Understood. I have confirmed it with Netros."
"Then, I shall begin. Amnesia, August 5th..."
The procedure itself was finished in an instant.
"I will verify the results with Read Info."
Read Info was a variation of Trans Info that bypassed the step of writing to a magi-crystal. Since the information was processed instantaneously, it required someone with Laojun's immense processing power to be of any use.
"Now... Read Info....It is done. All memories from the point of her capture on August 4th onwards have been erased."
"I see. It worked..."
Jin felt a wave of relief as the weight lifted from his shoulders. "Alright, let's take Istalis back to Nidou Castle."
"Jin! Did it work?"
The moment he returned to Nidou Castle, Sion rushed up to him.
"Yeah. She'll still remember being captured on August 4th, but she shouldn't have any memories after that."
"Will this... will she really be okay?"
"I don't know for sure. But without those painful memories, she shouldn't be trapped in that madness anymore."
The human heart was a deep and complex thing; there was always a chance things wouldn't go as planned. But Jin was betting on Sion's love for her sister.
"She should wake up in less than an hour. Stay by her side."
"I will."
"Jin-dono, I have a request."
Netros, who had finally recovered enough to stand, called out to Jin.
"Could you... erase my memories as well?"