"The Hourai Island Honeymoon Fleet continued its journey south even after our return. First, it pushed further south from Alcyone Island....Laojun!"
"Yes, My Lord."
Responding to Jin's call, the magic projection window—the magi-screen—on the wall illuminated.
"To the south of the Pleiades Archipelago, there lies an even larger chain of islands."
"Whoa."
The voice of one of the observers rang out.
"For the time being, I will display a general map of the Minakata, though the images are somewhat low-resolution."
"Oh!"
"Look at that!"
Jin's own memory was fuzzy on whether he had shown them this before, and since there were likely members seeing it for the first time, he decided to display the map as the foundation for their discussion.
"This map was compiled from data provided by the Watcher satellite, so some details remain indistinct."
Jin added that in certain parts of the Southern Hemisphere, the Sky squad had been unable to perform detailed surveys due to the nature of the local ether distribution.
"As we can see from this data, there is no continent at the South Pole either."
He specified "either" because it was already established that no continent existed at the North Pole.
"I see. So this is how the world is shaped," Toa muttered, looking deeply impressed.
"According to No. 700672, there were no indigenous people on the other continents. Therefore, it's highly probable that no human civilization exists there even now."
"That makes sense," Vivienne agreed.
"Large organisms also seem to be scarce. There is likely a high correlation with the concentration of free ether," Goose noted. As always, his interest in unknown biology was exceptional.
"Regarding the distribution of free ether, it follows a gradual downward trend. At present, any magic tools that haven't been specially adjusted may malfunction south of the Tropic of Capricorn."
"Understood. Thank you."
Jin nodded and scanned the room.
"I've recently encountered a major question regarding the distribution of free ether. Would you all mind hearing me out?"
"Of course."
"Let’s hear it."
"I'm curious as well."
No one objected.
"Alright. To recap the distribution: the concentration of free ether is highest in the north and decreases as you move south."
"Right."
"The rate of change isn't linear. There is roughly a threefold difference between the demon territory—effectively the northern limit of human habitation—and Port Rock Town, which is essentially the southern limit."
"That's right. Our recent trip was near the equator, so even though the levels dropped, the difference wasn't enough to feel physically," Reinhard said, nodding in comprehension.
"Generally speaking, if we were to graph the horizontal distribution of free ether, I imagine it would look something like this."
At Jin's signal, Laojun projected a graph onto the magi-screen.
"The horizontal axis represents latitude, while the vertical axis shows the concentration of free ether. If we set the South Pole at zero and the North Pole at ten..."
"I see. It doesn't change at a constant rate," Saki observed.
Indeed, the graph displayed a curve that rose toward the right and was concave-up.
"I think everyone can follow me that far. Next is the vertical distribution. Once you enter space, the imbalance in ether concentration virtually disappears. Everyone remembers that, right?"
"Yes, I believe you mentioned that before," Toa said, and the others nodded.
"Right. So, if we take the South Pole as an example, the question is: at what altitude does the concentration begin to drop? The answer is roughly from the stratosphere downward."
"Hmm. So far, nothing seems particularly out of the ordinary?"
"Agreed."
Toa, Goose, and the rest of the group nodded.
"I know. But here’s the thing," Jin said, looking each person in the eye.
"If free ether is composed of particles, I suspect they are smaller than hydrogen atoms. That would mean they are capable of moving at considerable speeds."
"Because their mass is so low!" Hanna interjected.
"Exactly, Hanna. And that's exactly why the current bias in the ether distribution is so strange."
"...Ah."
Elsa, grasping the implication, let out a soft sound of realization.
"It looks like Elsa has figured it out."
"...Are you saying that free ether might still be being consumed even now?"
"What?...Oh! I see!"
Hearing Elsa’s remark, Saki understood as well.
"So that's what you mean!"
"That's certainly one way to look at it!"
Voices of realization filled the room.
"You're getting it. My question is this: is the reason for the ether shortage in the Southern Hemisphere because it is still actively being depleted somewhere around the South Pole?"
"Yeah, that’s a hard theory to deny," Reinhard agreed, his expression growing serious.
"S-So, what you’re saying is this, Jin? If the ether in the Southern Hemisphere had been depleted by something in the distant past, the distribution should have naturally equalized by now."
"Exactly, Beena. You hit the nail on the head."
"...So you're suggesting that a factor still exists in the Southern Hemisphere today that continues to reduce the ether?"
Stearena nodded, tracing the path of Jin's logic.
"Precisely. Whether it's being consumed or pushed away by something... I don't know yet."
"Hmm..."
"I see..."
As they grasped the weight of the question, everyone fell into a thoughtful silence.
"If it were just a one-time event in the past, the levels should have returned to normal long ago."
"Wait, Jin. What about the Ether Stampede?"
"Oh, that's right. Didn't the concentration drop to a third of its previous levels after that?"
Jin nodded.
"Yes, and that's another mystery. Let me share one more observed fact. The current ether concentration near Kaina Village is almost identical to the concentration found in space."
"What!?"
"Does that mean that in ancient times, Ars had an ether concentration much higher than the planetary average?"
A startled Reinhard correctly identified the core of Jin's argument.
"I believe so, Reinhard."
"Wow... I see why you’re so puzzled, Jin."
"Right?"
Viewed as a whole, the distribution of ether on Ars was unnatural. Jin found the lack of an explanation deeply unsatisfying.
"Even No. 700672 didn't seem to have the answer."
"Indeed. And I don't think Jack knows anything about it either," Milowina added.
After all, the Moon—Uni—where she now lived was originally an asteroid that the Progenitors had placed in orbit to serve as a satellite for Ars. It seemed that even Uni lacked records concerning the terraforming or development of Ars itself.
"Laojun and I have developed a few hypotheses. I'll share the one we consider the most likely. Laojun, go ahead."
Jin signaled Laojun to take over the briefing.
"Yes, My Lord. Based on the data from No. 700672, it appears that the people known as the Progenitors required a high concentration of free ether to thrive. Consequently, it is probable that they used some method to artificially increase the ether concentration on Ars."
"That’s the first point," Jin noted.
"To achieve this, they may have prioritized populated regions, focusing their efforts on boosting the concentration in the Northern Hemisphere while leaving uninhabited areas for later."
"That’s the second point."
"Therefore, we speculate that rather than something simply consuming ether in the Southern Hemisphere, there may be 'something' actively diverting it toward the Northern Hemisphere."
"And that's the third point. What do you all think?"
Jin looked around at the faces of his family.