"Happy birthday!"
On the night of August 2nd, the members of the Jin Family gathered on Hourai Island to celebrate Stearena's birthday.
"Thank you, everyone."
Nearly every member was present to offer their well-wishes.
"Though... turning thirty-three isn't exactly a milestone worth cheering for," Stearena added with a sheepish smile.
Berche was the first to counter that sentiment.
"It may be a cliché, but a birthday is a celebration of the day a person was born. It's not about celebrating the fact that you've grown older."
"Exactly. I feel the same way," Jin agreed.
"I think so too, Lina," her husband, Toa, said as he rested a hand on her shoulder.
"You're right. Thank you again, everyone."
With the formalities concluded, the gathering shifted into a jovial banquet.
The spread in Hourai Island’s grand dining hall was magnificent. There were sushi-style dishes made with rice and hotcakes drizzled with generous amounts of maple syrup. There was passa bread—baked with dried raisins—and sandwiches stuffed with a variety of fillings.
Drinks were equally plentiful: persica, citran, and apulul juices, along with frape, lamber, and brule juices.
"Berche, are you still feeling alright?" Toa asked. As a father himself, he was naturally attentive to her well-being.
"Yes, I'm quite fine. While long-distance travel is out of the question, simply coming here doesn't place any burden on me."
"I'm glad to hear that. Just be careful not to let your stomach get cold or overexert yourself."
"I will. Thank you."
Nearby, Elsa was speaking to Marcia. "Marcia, congratulations on your victory."
"Ah, thanks!"
"Winning the Golem Boat Race two years in a row is an incredible feat. You should be proud."
"Thanks. But really, it’s all thanks to Jin. I only entered because Liche fell ill, and I barely had time to practice. I never could have won without Arrow."
"Don't sell yourself short," Jin interjected. "I think Rodrigo's hull design was truly impressive as well."
"R-Really? Hearing that from you, Jin-dono... it's a bit embarrassing," Rodrigo admitted.
"No, really—that trimaran was a wonderful piece of work."
While the designers talked shop, the visitors from Blue Land looked on in awe.
"Good heavens, this place is a paradise!" Louis, Count Kuzuma, exclaimed.
"I’m honestly speechless when it comes to Jin," his wife, Beena, added, though her eyes were shining with wonder.
Meanwhile, Jin was back to discussing technical matters with Stearena. "...I see. So, the Fluid Form Drive, huh?"
"Yeah. It seems to be an extension of the Form Drive Stearena uses for units like Celes," Jin explained.
"I'm a little interested," Stearena admitted.
"But for now, the system is mercury-based. Since it's highly toxic, I can't really recommend it for general use."
Saki joined the conversation as they discussed the hazardous material. "Heh, so it uses mercury? That’s fascinating. But it really is harmful, isn't it?"
Saki had been warned about the dangers of the substance back when she received a sample of mercury in Mitsuho, but her scientific curiosity was easily rekindled. "I wonder if simply wearing rubber gloves would be enough to handle it?"
That specific sample had ultimately been placed under Hourai Island's strict management, and since Saki's interests had shifted elsewhere, she hadn't been permitted to experiment with it.
"Saki-nee, mercury evaporates into a vapor," Elsa warned sternly. "If you inhale it, it’s incredibly dangerous. Even I might not be able to treat acute poisoning."
"I-Is that so? That sounds a bit too terrifying..." Saki muttered. For a researcher as relentlessly curious as her, a bit of intimidation was often the only way to ensure safety.
"The other thing I’m interested in is that kite-style airship," Reinhard noted, joining the circle.
"I agree. It’s a fascinating concept," Jin said. The design—which was just one step removed from a motorized hang glider—was certainly intriguing. It was likely a common sight five hundred years ago.
Reinhard let out a long sigh. "But still... a religion, huh?"
"Nowadays, when people think of religion or churches, they just think of tourist attractions," Jin remarked.
During the Great Magic War three hundred years ago, the authority and influence of religious institutions had utterly collapsed.
"But throughout history, religion has often been the root of a great deal of trouble," Jin said, thinking back to the history of his home, modern-day Earth.
Religious wars. That was the first term that sprang to mind. Gods that were supposed to be worshipped, gods that were supposed to protect the people, being used as justification to force death upon non-believers and followers alike. Jin had always found the concept deeply irrational.
"If it's possible to find out more, I’d like to understand what happened back then," Jin mused aloud.
Vivienne was the one who responded to his quiet thought. "I feel the same. From the bits of information I've gathered, it seems that because magi-craft was undervalued by the authorities of that era, the magi craftsmen ended up migrating to rural areas."
"So there was an era like that..."
The 'Lost Past' remained shrouded behind a thick veil of mystery.
"What caught my attention most was the origin of that liquid metal," Jin continued.
"I believe they mentioned a southern island," Vivienne said.
"That's the problem." Even if they knew it was a "southern island," there were countless islands in that direction, making it impossible to pin down the exact location.
"But surely there can't be that many candidates?" Rodrigo asked, sounding doubtful.
"What do you mean?" Jin asked.
"Well, it depends on the level of magi-engineering five hundred years ago. Even if they were more advanced than we are now, I don't imagine they could have traveled across the vast ocean indefinitely."
"I see..." Jin looked toward the horizon in his mind's eye. Looking at the world map, a chain of archipelagos dotted the sea starting from the southern tip of the Kingdom of Elias, near Port Rock Town, and stretching toward the southwest. "I suspect it's one of those."
However, he had no proof.
"In the first place, free ether levels decrease the further south you go, right?" Vivienne joined in. "So I don't think the island could be that far south."
"I wonder about that," Reinhard said, looking thoughtful. "Since this was before the Ether Stampede, wouldn't there have been a decent amount of free ether five hundred years ago?"
Jin nodded in agreement. "I think that's very likely. But even so, if the technical peak of that era was the Fluid Form Drive and the kite airship, they probably couldn't have gone extremely far. They didn't seem to have truly large-scale vessels back then."
"I understand your point, Jin-kun," Stearena said. "But the problem is the current state of things. There's so little free ether now, isn't there? It’s not as if we can just sail down there for a look."
Stearena’s point was sharp. Without free ether, magic tools and Magi Machines simply wouldn't function.
"True. But why is the free ether so sparse in the south?" Saki wondered aloud.
"It certainly is a mystery," Jin said. "For instance, outer space is filled with free ether, which means a spaceship could technically reach the southern hemisphere of Ars without any trouble."
He mentally added the caveat that this only applied if they stayed at an altitude higher than the stratosphere.
"I'd really like to investigate the cause of all this..."
Saki gave a knowing smirk. "Heh. Jin, are you plotting something?"
"Maybe. Think about it—what if there was a vehicle that could operate for an entire year without needing to be replenished?"
Saki began to run the numbers. "...That would depend on the speed, but if it were a ship and could maintain a speed of, say, twenty kilometers per hour, it could easily make it to the South Pole and back."
Her calculations were sound. The circumference of Ars was roughly 7,500 kilometers. At twenty kilometers per hour, a vessel traveling around the clock could circumnavigate the globe in less than sixteen days. Even if it only traveled for twelve hours a day, the trip would take about a month. That was more than enough time to conduct thorough surveys at various stops.
"...But Jin, you're not actually serious about going, are you?" Saki asked with a wry smile.
Jin laughed, but there was a spark in his eyes. "Well, I think I’d really like to see it for myself."
He thought of the unknown islands he had only ever glimpsed from the high-altitude reconnaissance of his aircraft. The mystery of the south was a call he couldn't ignore.