After the Konron 2 took off, Elsa, who had remained behind in the Capricorn 1, also returned to Hourai Island via a Warp Gate.
In her place, Land 3 was deployed to manage the Capricorn 1 on-site until the Jin Double returned.
＊ ＊ ＊
At the Konron 2's cruising speed, the trip to their destination at the Elrad Mine was a mere hop away, arriving in roughly two hours.
As for the low concentration of ether, the problem was solved by having Belialus drink some "Hourai Island specialty" Persica juice.
A single glass of juice seemed enough to sustain him for half a day. While he usually absorbed ether through respiration, the example of No. 700672 had proven that oral intake was just as effective.
"That was incredibly fast. Just how much speed were we making?"
To Belialus's question, the Jin Double replied that they were traveling at about 150 kilometers per hour.
He added for context, "It's about two or three times faster than a horse at a full gallop. Ah, come to think of it, I believe a Grandragon's sprint is roughly the same."
Leaving Belialus at a total loss for words, Jin observed the surrounding terrain from above.
Below them loomed a mountain that likely exceeded 2,000 meters in height. This was surely Mt. Elrad.
Mt. Elrad had a long, narrow profile stretching from east to west. On its eastern foothills sat the Elrad Mine, while the Elrad Ruins lay on the southwestern slopes.
"I suspect the Elrad Ruins might hold the key to the entrance."
"I agree."
The Jin Double and Reiko conferred and decided to land near the ruins.
One deciding factor was that the Elrad Mine side saw at least a modicum of foot traffic.
After bringing the Konron 2 down into the shadow of some rocks, the Jin Double, Reiko, and Belialus leaped from the vessel. All three carried small packs on their backs containing food and emergency gear.
The Konron 2 ascended immediately after. It was set to remain on standby at an altitude of approximately 3,000 meters.
"Well then, shall we get started?"
Since they had confirmed the path from the air, the route to the ruins was clear. The group headed there at a brisk pace.
"So these are the Elrad Ruins..."
He had known the general layout from the Quinta reports, but seeing them up close—even through a magi-screen—was quite impressive.
If there were a style of architecture on Earth that came close, it would perhaps be Byzantine. Buildings with dome-shaped roofs and the towers surrounding them were the most prominent features.
Of course, they weren't identical; there were many differences. The scale here was much smaller, and the materials used weren't just stone; metal was integrated in various places as well.
"The style is somewhat similar to our own," Belialus murmured as he observed.
"According to the information we gathered, this place has already been here for about 500 years. For its age, the exterior hasn't weathered much at all."
The Jin Double gently touched the surface of the outer wall.
(...As I thought, 'Toughening' has been applied. And quite a powerful version of it, too.)
Toughening was a form of Craft Magic used to make brittle substances more resistant to cracking. It was the perfect treatment for protecting against the elements.
"Jin-dono, let us go inside," Belialus said urgently. He clearly wanted to find a clue about his sister as soon as possible.
"Right, let's go."
The Jin Double took a headlamp out of his pack. It was a lamp designed to be worn on the head—a magi-lamp, rather than an electric one.
"This is excellent. Having both hands free is a great advantage."
By its nature, it illuminated whichever direction the wearer was looking.
The Jin Double and Reiko could perceive infrared, so they would have been fine without light, but things were still much clearer with a source of illumination. More importantly, for Jin, who was watching through the magi-screen, light was essential.
The group slowly stepped into the ruins.
"There's a bit of a musty, moldy smell," Belialus said, covering his nose and mouth. The Jin Double and Reiko did not breathe, so it wasn't an issue for them.
"Belialus, use this."
The Jin Double took out a simple anti-odor mask he had made for occasions like this. It featured a filter made of charcoal powder sandwiched between layers of fine, thin felt, so it offered a reasonable degree of protection.
Though unnecessary for anyone but Belialus, the Jin Double wore one as well for the sake of appearance.
"This is quite effective," Belialus noted, his voice muffled by the mask.
"The objective is underground. Let's look for stairs or hidden passages."
While observing calmly, the Jin Double stated the plan.
"Understood."
The three of them walked slowly and carefully, scanning their surroundings. Reiko also checked the atmospheric composition, mindful that Belialus was flesh and blood.
"A staircase like that wouldn't be in a place where people can normally come and go. It must be cleverly hidden."
The Jin Double spoke as if to confirm his thoughts with Reiko.
"I believe so as well."
Since this part of the ruins was accessible to commoners, it was safe to assume there were no dangerous or particularly valuable things left in the open.
They searched for about an hour but found nothing.
"It's time to change our approach."
It was time to try magic. However, since the results were an unknown variable, they decided to step outside and try it from there first.
The plan was simple: if nothing happened, they would move back inside and continue the investigation step by step.
"Sonar."
...However, there seemed to be no hollow spaces anywhere.
"Let's go a bit deeper."
They tried Sonar again there, but they could not detect any cavities.
After repeating this dozens of times, it appeared there were no hollow spaces at all within the ruins.
"Hmm..."
The group had hit a dead end. The sun was low on the horizon, about to set.
"Let's call it a day for now."
Watching from before the magi-screen, Jin thought that they might need to change their method of approach entirely.
"...I... suppose so," Belialus replied, his face weary. He clearly wanted to keep searching, but he couldn't hide his fatigue.
They signaled the Konron 2 and boarded. Inside, there was enough living space for three people to stay overnight.
That said, neither Reiko nor the Jin Double needed to sleep. It was only Jin, who was remote-piloting, who required rest.
『My Lord, I will take over the controls in the meantime, so please rest.』
Leaving things to Laojun, Jin decided to take a break.
＊ ＊ ＊
They continued the search the next day as well, but with no results.
Just past noon, an idea occurred to Jin.
"Maybe the entrance isn't in the ruins, but in the mine itself?"
"Hmm, that is a possibility."
So, they decided to investigate the Elrad Mine that afternoon. Their basic strategy was to go to the very back of every single tunnel.
Since there were only about three prospectors there that day and the rest was quiet, they managed to check all the tunnels before sunset.
However, the result was "no success."
"Man, this is tough."
He had hoped to find something more substantial. Just then...
"There seems to be something beyond this," Reiko called out while investigating the southernmost tunnel.
"Really? Let's check it thoroughly. Grand Search... What's this?"
There seemed to be a magical "echo."
"Hmm, but this feels like something natural..."
As Reiko dug further into the rock with her bare hands, the anomaly became clear.
"I see, this feeling is..."
"Ah."
Just as Jin finished analyzing the information from the Jin Double, Reiko dug out a certain ore.
"Just as I thought."
It was a massive piece of Mityanite—also known as Elradrite. It was cocoon-shaped, a mass nearly fifty centimeters in diameter.
"Incredible..."
Since it was the Elrad Mine, it was natural to find Elradrite, but something this massive was exceptionally rare.
If they carried it out as it was, it would be forcibly purchased by the administrators monitoring the tunnels. Even if they tried to hide it, there was apparently detection magic that targeted the specific properties of Elradrite, so they wouldn't be able to conceal it for long.
"Alright, let's teleport it out."
Fortunately, Belialus was investigating a different tunnel, so he wouldn't notice.
Jin, on Hourai Island, quickly created a transporter gun with the destination coordinates adjusted. Laojun delivered it to Reiko via a transporter, and Reiko then teleported the Elradrite to Hourai Island—a rather convoluted way of doing things.
"But once it's made, the rest will be easy."
By "the rest being easy," he meant having the transporter gun ready for future use. Naturally, the procedure involved teleporting the ore to Shinkai first rather than directly to Hourai Island, then forwarding it from there. This was a safety precaution.
The settings for the gun that had previously sent the Frost Dragon carcass had been set to go directly to Hourai Island, so he had already reset those once.
On this day, the greatest harvest was the Mityanite...
Still, no clues regarding Arshel had been found.