Just as Ichi and the other spiritual lifeforms had learned the skill of manipulating free ether from Jin, Jin had likewise gained a measure of knowledge from them.
Most of it pertained to the concepts of time and space.
[Time is likely too high-order for your understanding. Space also requires high-order comprehension, but since its dimensions are lower than those of time, you may be able to grasp some of it.]
With those words, Ichi began to explain the concepts of time and space to Jin.
[This knowledge will likely be of no practical use in your world, Jin Nidou. However, it may prove useful for... something else.]
Along with these enigmatic words, Ichi provided Jin with various explanations.
[@+*<?v#0(&, why are you providing that organic lifeform with unnecessary knowledge?]
"@+*<?v#0(&" was Ichi’s true name.
Ichi—or rather, @+*<?v#0(&—replied to the question.
[Jin Nidou is indeed an organic lifeform, but he uses his skills to construct pseudo-biological brains he calls magi-brains. I thought that such brains might be able to put this knowledge to use.]
This was information only Ichi could have known, having spent the most time in contact with Jin.
[Magi-brains, you say? Do they truly rival us?]
[No, I would not go that far. However, their limits appear to be higher than those of an organic brain.]
[So you believe that, given enough time, they might achieve something?]
[Precisely. Jin Nidou is a stray soul. Assisting him is our duty.]
To these spiritual lifeforms, Jin—and by extension, all humans—was perhaps something akin to a puppy or a kitten.
They felt a protective instinct toward Jin, much like the affection one feels for a lesser creature.
Of course, they also felt a sense of gratitude for being taught the skills to handle free ether.
However, that gratitude was not much different from the feeling of being healed by petting a puppy or a kitten.
Nevertheless, their mentality dictated that they would exert their maximum effort to ensure Jin was returned to his original world.
[Jin Nidou, using the skills I obtained from you, it seems we will be able to prevent our two universes from making superposition contact.]
"That is good news."
Three days had passed in Jin's perceived time since he had become trapped in this world. Ichi was now sharing new information with him.
[The methods... or perhaps I should say, the techniques you were experimenting with through trial and error in your world... You once attempted to generate sub-ether waves, did you not?]
"Yes, I did try that."
[In sending you back to your world, we wished to minimize the margin of error as much as possible. We should be able to use those waves as a beacon.]
Sub-ether waves were detectable even from another universe. By using them as a reference, they could send him back in a few days' time.
Jin felt immensely relieved upon hearing this.
[However, you must understand that an error will still occur. To borrow an analogy from your own memories, it is like aiming at a target with a bow or a gun from a great distance. An error is inevitable, and the shot will inevitably stray, however slightly.]
"That can't be helped, I suppose."
Jin could only nod in agreement.
[Furthermore, as one of the rules of the high-order dimension of time, we must avoid the simultaneous existence of identical or equivalent entities.]
It was the phenomenon known as a time paradox.
[Therefore, with the target point set at zero, the error will likely shift in the positive direction.]
In short, since having two Jins at once would be problematic, he would likely appear at a point slightly further along the timeline—in the future.
As for how far into the "future" that would be, they could not say for certain yet.
[If we were within your own world, the reference points would be clear, and the error could be kept to a minimum.]
In that case, they could have specified not just the year, but the month, day, hour, and minute.
[Another point is that crossing through time requires a staggering amount of energy.]
"I can imagine that much."
[Indeed. In your understanding, nothing can exceed the speed of light, correct?]
"Yes."
[In high-order space, that rule comes with a caveat: 'within the energy obtainable in that space.'...Well, this is also a somewhat simplified explanation.]
Ichi added that laws involving high-order space were likely beyond the comprehension of an organic lifeform.
[Still, there is no harm in hearing the concepts.]
"I see..."
And so, Jin ended up listening to Ichi’s long-winded explanations of space-time concepts for what felt like an eternity.
[What do you make of that organic lifeform, Jin Nidou?]
[He is fascinating. Interestingly, it seems he has already crossed between worlds once before.]
[Oh?]
[Apparently, an artificial pseudo-creature called an automata discovered a way to cross worlds and summoned Jin Nidou to his current home.]
[I see... That is indeed intriguing.]
[Is such a thing even possible?]
[There must have been some kind of hint. That, and a fair amount of luck.]
[Even if it looks like a series of coincidences, it was... was it 'inevitable'?]
[We cannot yet read such inevitabilities, however.]
[We've strayed from the topic. Can we send him back?]
[Yes. Though a certain degree of error is unavoidable.]
[That is only to be expected.]
[The rest will be up to Jin Nidou. It is his own world, after all.]
On the fifth day of Jin's perceived time, spiritual lifeforms other than Ichi came to "meet" him.
[Jin Nidou, preparations to send you back to your original world are complete.]
"Oh, really? Thank you so much!"
[We can proceed whenever you are ready.]
"I don't have anything in particular to..."
[You may take some of the matter lying around here with you if you wish.]
"Is that so?"
Thinking it would make a good memento, Jin picked up three walnut-sized stones—one white, one red, and one blue—and tucked them into his pocket.
[Will that suffice?]
"Yes."
[Very well. Then come this way.]
One of the spiritual lifeforms, who appeared as nothing more than a faint, blurry shadow to Jin's eyes, seemed to beckon him forward.
[One last thing. Even we are not perfect. The possibility that your destination is not the world you came from is not zero.]
"I understand that it's a risk I have to take."
Jin felt that as long as it was a world where humans could survive, it would be better than where he was now.
He had to return to the world where Elsa, Hanna, Reiko, Laojun, and the rest of the Jin Family were waiting.
He was prepared to face a small amount of risk for that goal. If he did nothing, his chances of seeing them again were non-existent.
[Then there is the temporal error. This, too, is due to our limitations.]
"I believe I understand that as well."
[Very well. We can at least guarantee that your destination will be an environment suitable for the biological activities of Jin Nidou.]
Fragile organic lifeforms cannot survive even a slight degradation in their environment, the spiritual lifeform noted.
[One more thing. Moving against the 'potential' may be difficult for an organic lifeform. This is merely a conjecture, however.]
"I'm prepared for that."
[I see....Then let us begin. Are you ready?]
"Yes."
There was nothing for Jin to actually prepare. It was merely a question of mental readiness.
"Ichi, and everyone else... thank you for everything."
[The pleasure is ours. We thank you for providing us with intellectual stimulation that we can enjoy for a long time to come.]
Then, a glowing white sphere manifested before Jin's eyes.
[This is the 'Gate' that leads from here to there.]
"Then, goodbye."
[Fare thee well.]
Without hesitation, Jin stepped into the Gate... and lost consciousness.