September 14th. Jin woke to a refreshing morning.
There was something uniquely reassuring about sleeping in one's own home, in one's own room, in one's own bed.
"Father, are you awake?"
Sensing that Jin had stirred, Reiko, who had been waiting in the next room, slid the fusuma open.
"Yeah. Morning, Reiko."
"Good morning. Soleil and Luna have prepared breakfast for you."
"Oh, have they? I’m looking forward to it."
It had been quite some time since he’d enjoyed their cooking. Jin rinsed his mouth, washed his face, and headed for the dining hall.
The spread consisted of rice, miso soup with aburaage and okara, toasted nori, tamagoyaki, natto, and oshinko. The tea was hojicha.
Every ingredient had been harvested right there on Hourai Island.
"Yeah, this is the stuff."
Jin was deeply satisfied. The seasoning hadn't changed a bit in four hundred years.
"Ah—I’m stuffed."
Nostalgia had gotten the better of him. Jin ended up polishing off four bowls of rice and three helpings of miso soup. He leaned back in his chair, rubbing his stomach contentedly.
He couldn't remember the last time he’d been able to relax with such a peaceful state of mind.
"Father, would you like another cup of tea?"
"Ah, thanks. I’ll take one more."
"Certainly."
The freshly roasted tea was highly aromatic and left a clean, crisp aftertaste. In the end, Jin had three refills of the tea as well.
After taking a leisurely rest for about an hour and a half, Jin decided to put the ideas he’d ruminated on last night into action.
"Laojun, have there been any leads on the two missing Quinta units?"
『Yes, My Lord. I have been searching for them using the magi-radar, but they have not been discovered yet.』
"I see... Alright, keep up the search. I’ll be in the workshop. Reiko, give me a hand."
"Yes, Father."
Jin headed to the workshop to give shape to an idea that had come to him while lying in his futon the night before.
He needed to find the missing Quinta.
The golems and automata Jin built were equipped with emergency protocols for use if they fell into enemy hands, designed to self-destruct or perform an automatic Erase to prevent their data from being stolen.
However, a Magi Emulator changed the equation. It could trick them into misidentifying an enemy command as an order from Jin, allowing the captors to handle them at will.
Jin feared that, in the worst-case scenario, the two units might have been stripped down—literally "disassembled."
In that case, the most vital components would be the control core, the magi-reactor, and the force generator.
That being said, since the magi-formulas Jin employed were interlaced with Japanese and kanji, it should be impossible to even repurpose them, let alone reverse-engineer them, without first deciphering the language.
"But I can't afford to be complacent... Let's see."
Jin pulled his straying thoughts back to the task at hand.
"Father, what are you planning?" Reiko asked. She hadn't yet been briefed on what Jin intended to do.
"The fact that Laojun can't find them means they either no longer exist, or they’re being shielded by a barrier," Jin explained.
"That would seem to be the case..."
At the mention of the possibility that they "no longer existed," a shadow of sadness crossed Reiko’s face.
"But I don't believe that's what happened. I refuse to believe that the Quinta units I built could be broken by some second-rate magi."
"Y-You're right!"
The materials used in them were of the absolute highest grade. Aside from Reiko herself, one could arguably say nothing better existed in the Known World. Naturally, their magic resistance was equally formidable.
Even if a Magi Emulator could force them to obey to some degree, they wouldn't be so easily dismantled. Jin had faith in his own craftsmanship.
He shifted his perspective, returning to the fundamentals.
"I’m going to perform a thorough analysis of the Magi Emulator."
He understood the operating principles, but he realized he hadn't performed a rigorous breakdown of the device itself yet.
Magi Emulators had already been recovered from the captured golems and ships. Jin immediately set to work.
"Hmm... There wasn't much to gain, but... this one section is interesting."
"Father?"
"Yeah. With this structure, it generates only a specific mana wave—mine, in this case. If I were designing it, I’d make the output adjustable... Well, setting that aside, look at this generating element."
Jin pointed to a component that resembled a tiny LED light.
"It generates mana waves at the base, modulates them through an internal unit, and then adjusts them with a filter. I wonder if a typical magic-biased researcher could even come up with this concept..."
Despite their reliance on magic, Jin felt the creators were employing a very scientific methodology. However, since there was no point in dwelling on the enemy's origins further, Jin switched gears.
"Back to the task. In the end, the Magi Emulator's output is definitely an ether wave."
Jin spoke his confirmation aloud.
"You can block this with a standard barrier. But the trade-off is that it also makes detection via magi-radar impossible."
This was a natural limitation of the magi-radar's principles. But Jin had a solution that bypassed that rule.
"So, we just have to make it so we can detect them even through a barrier," Jin said matter-of-factly.
"Just how do you intend to do that?"
"By using sub-ether waves," Jin replied. "Sub-ether waves aren't blocked by standard barriers."
"I see. As expected of you, Father!"
『My Lord, so you have noticed.』 Laojun’s voice echoed in the room.
"Laojun, that's the answer, isn't it?"
『Yes, My Lord. When you returned to your original era four hundred years ago, you modified me.』
According to Adriana Tierra’s theories, mastering sub-ether waves was essential for transcending time and space. For that reason, it seemed the future Jin had upgraded Laojun.
『Because the version of you that returned to the past modified me, I am now capable of handling sub-ether waves to a certain extent.』
"Just as I suspected. You boosted Laojun's processing power so he could manage sub-ether waves... by about a thousand times the original capacity, right?"
『Yes, My Lord. That is correct.』
"I suppose I shouldn't ask how I did it for now."
Jin figured his future self—the one who returned to the original era—would be the one to devise the method. It was just one more thing added to his eventual to-do list.
Since it involved time paradoxes, he didn't want to overthink the mechanics, but Jin had suspected that the current Laojun would be capable of mastering sub-ether. Furthermore, he presumed that the automaton that was Reiko’s predecessor had likely mastered sub-ether waves in a limited capacity as well, using them to summon him to this era.
"Presumably, the key is the energy requirements?"
『Yes, My Lord. It is made possible by consuming almost the entirety of the free ether cloud that has been continuously funneled to Hale.』
"I figured."
Transcending time and space required the depletion of nearly all the free ether gathered over tens of thousands of years. For Jin, this intentional time travel would likely be a one-time deal, dictated by energy constraints. If he ever wanted to do it again, he would have to wait another few tens of millennia for the ether to accumulate.
Thinking about it that way, he felt a surge of gratitude for the system that had kept gathering the free ether of Ars long after it was seemingly no longer needed.
"Honestly, you never know what might turn out to be a blessing," Jin murmured with a sigh.
He speculated that Reiko’s predecessor must have also struggled to gather the free ether and mana required to bridge the gap between dimensions.
"Alright. I’m going to modify the magi-radar to use sub-ether waves as carrier waves."
The current Laojun should be able to handle the load. As for the mana consumption, since they weren't actually trying to tear through space-time, the magi-reactor would be more than enough to power it.
"Laojun, you can emit sub-ether waves, right?"
『Yes, My Lord. It is well within my capabilities.』
"Good. I won't ask for the technical specifics. I'm sure the 'me' who returns to the past will figure it out eventually."
With that, Jin threw himself into the task.
Three hours later, through Jin’s true prowess, the new magi-radar was complete.