"Without relying on magic, huh..."
Jin understood Elsa's point perfectly. However, providing all the necessary energy for their journey without relying on free ether was next to impossible.
At the very least, they wouldn't be able to fly the spaceship without it.
"Is there any guarantee that we can find enough free ether in space?" Elsa asked.
"The Watcher has already confirmed its presence, and so did the first prototype spaceship. Though, we haven't reached lunar orbit yet."
Additionally, there was the fact that the Progenitors had traveled to Ars in spaceships powered by magi-engineering. That was five thousand years ago, but on a cosmic scale, it was merely the blink of an eye.
"Plus, we can always bring plenty of ethenol with us," Jin added.
"...Mm."
Elsa still looked uneasy, so Laojun offered a clarifying explanation to soothe her.
"Elsa-sama, should a situation arise where free ether vanishes from space and the Magi Machines cease to function, you will be safe as long as you use a Warp Gate to escape before they reach a complete Stand Still. We can certainly buy enough time for that."
"...I see."
Hearing that from Laojun finally seemed to put Elsa at ease.
"But how far do the Warp Gates actually work?"
"That is one of the parameters we intend to test from here on."
"In that case, we might need to build relay bases in space too, like Shinkai."
Jin nodded at the suggestion. "Exactly! Elsa, that's a brilliant idea. Let's start building them soon!"
"And one more thing," Elsa continued, her face clouding with a fresh concern. "If we end up in a space where there's absolutely no free ether, what will happen to Jin-nii and me?"
"Ah... it would likely be a much more severe version of what happened when Sion and her people first arrived."
Sion belonged to the demon race. As descendants who carried the blood of the Progenitors more densely, they were particularly vulnerable to ether deficiency.
"In the case of a magi, I doubt death would be instantaneous, but your physical condition would deteriorate rapidly. If that state persists, it would eventually lead to death."
"Which is why Persica juice would be so effective," Laojun added.
As long as they had internal free ether and the mana transformed from it, they could manage by supplementing their levels with things like Persica juice.
It was like being in an environment with normal air pressure but no oxygen. As long as you had an oxygen tank, you could survive.
In other words, they would be fine as long as they had a dedicated "free ether tank."
If they equipped a magic tool like an ether condenser, they could compress the ambient free ether, making it unlikely they would ever hit a true zero state unexpectedly.
"Adding an ether condenser function inside the spacesuits would definitely provide peace of mind," Jin mused.
"...Yeah."
After such a meticulous explanation, Elsa finally relaxed.
"But that isn't exactly 'not relying on magic,' is it?"
"Well, you're right. Doing away with it entirely would be difficult right now."
"But at least for the lights, the air..."
Since a total replacement was impractical, Jin decided to focus on the areas where alternatives were feasible.
"We'll have to experiment with those as well..."
With that, Jin returned home with Elsa for the day, refreshing himself with a long soak in the bath. He spent a quiet evening recharging his batteries over a relaxing dinner.
That night, Jin sat in his room without lighting his magi-lamp. Reiko remained by his side in silence.
"Jin-nii, what are you doing?"
Elsa came by, wondering why his room was dark.
"Oh, actually..."
Jin explained he was considering what to do if magic failed. Elsa's expression softened into one of regret.
"...I'm sorry. It feels like I've given you something else to worry about."
"No, don't be. It's a necessary precaution."
As he spoke, Jin touched the magi-lamp, and light flooded the room.
"Lighting... in the old days, people used candles. And during power outages, they had emergency lights powered by batteries and solar cells."
Jin suddenly remembered the emergency kits used during typhoons and other disasters.
"Emergency lights... come to think of it, there was moonlight grass!"
It was the plant used for nightlights in Kari Village, near the entrance to Mitsuho. Jin realized they could serve as perfect emergency lamps.
"Reiko, tell Laojun..."
He immediately issued instructions to prepare samples.
"But make sure he doesn't harvest too many."
He was careful to ensure they wouldn't over-harvest the plant.
"Yeah, that should handle the lighting situation."
In the void of space, inside a sealed vessel, light was paramount. One could do nothing in a darkness so thick that even one's surroundings were indistinguishable.
"The rest is air and water."
Those were relatively simple problems to solve.
"I can just compress air and store it in adamantite pressure vessels."
Water could be stored in tanks as well. By using multiple separate tanks, a single leak wouldn't deplete their entire supply.
"Ah, I'll be able to sleep soundly tonight."
"I'm glad to hear that."
With his immediate concerns addressed, Jin felt a weight lift from his shoulders. Seeing him look relieved put Elsa at ease as well.
"...Well then, good night."
"Yeah, good night."
Back in her own room, Elsa let out a soft sigh. She was wearing a new pair of pajamas she had made, but Jin hadn't noticed them, let alone commented on them.
She had put quite a bit of effort into dyeing the magisilk a soft pastel green. She puffed her cheeks out in a slight pout.
In his room, Jin was thinking about Elsa's brief visit.
Those pastel green pajamas were new; she must have made them herself.
"...I really should have said something."
But it was too late now.
"Father, you really should have just spoken your mind," Reiko remarked.
"Well, yeah..."
Reprimanded even by Reiko, Jin reflected on his own lack of tact.
The next morning.
"Good morning, Elsa."
"Good morning, Jin-nii."
Though she used to be a late sleeper, Elsa had become an early riser since moving to Hourai Island, taking charge of preparing their meals.
"Oh, aburaage and okara this morning?"
"Mm."
Tofu was made from round beans and bittern extracted from seawater, yielding aburaage as well. The okara—the soy pulp left over after squeezing the soy milk from the round beans while making tofu—was also a staple ingredient.
Back at the orphanage, the Orphanage Director had been particularly fond of okara miso soup, which had led to it becoming one of Jin's favorites as well.
The meal was rounded out with umeboshi, pickles, and hojicha.
"Ah, this is delicious."
"Mm. I'm glad."
Seeing Jin take a sip of the miso soup and smile with satisfaction, Elsa picked up her own chopsticks. She had always been nimble, and by now she was perfectly proficient with them.
"Seconds, please."
"Right away, Father."
Reiko acted as the server, rounding out a peaceful morning scene.