"We might need to reconsider."
That night, the Jin Double, Reiko, and Belialus held a strategy meeting aboard the Konron 2.
"It stands to reason that the Mystery Servant's facility must have an entrance somewhere. I'm certain of that much."
"I agree," Reiko replied.
Even if the entrance wasn't currently in use, the fact that they hadn't found even a trace of it was highly irregular.
"Even if the Mystery Servant inhabits an automata body and has no need for food, Arshel or her clones are different. They wouldn't be able to survive without eating."
This observation from the Jin Double was an idea that the real Jin—currently brainstorming with Laojun on Hourai Island—had just devised.
＊ ＊ ＊
Back on Hourai Island, Jin and Laojun were deep in consultation. Elsa was also participating in the discussion.
"My Lord, regarding Arshel... or perhaps her clones? The individual who attacked Gloria-san and the others used Teleportation Magic, did she not?"
"...Ah, I see. So you're suggesting they might enter and exit the facility via Teleportation Magic."
"Indeed. It would serve as an excellent security measure."
"But wait, isn't there a problem with that? I thought Teleportation Magic could only take you to places you've visited before or places currently within your line of sight."
"Hmm, you're right," Jin mused.
"In that case, the question becomes how they got inside the very first time," Elsa added.
"Exactly. Either they entered the underground from somewhere else, or there's a specific location where one can establish contact with the Mystery Servant."
"That seems quite likely. The problem is finding out where that is."
"It might be in a place we'd never expect," Laojun suggested.
"If only we had some kind of lead..."
As the conversation continued, Elsa brought up a point that made Jin bury his face in his hands.
"By the way, Jin-nii. You pocketed that Elradrite you dug up, didn't you?"
"Eh?...Ah, ahhh!"
Jin only realized the implications once Elsa pointed it out.
Technically, the Elrad Mine was under the jurisdiction of the Celuroa Kingdom and its associates. Any Elradrite extracted there was supposed to be purchased by the state.
Regardless of whether that law was fair, Jin had effectively engaged in unauthorized mining.
"...I'll have to go and give King Cesar a formal explanation later."
"My Lord, I believe that would be for the best. In any case, a massive Elradrite of that scale isn't something a common local official could even begin to appraise."
"Understood. I'll do that."
Thus, it was decided that they would formally report the discovery of the Elradrite once the matter regarding Arshel was resolved.
＊ ＊ ＊
"The real question is how and where Arshel first encountered the Mystery Servant."
As the Jin Double muttered this thoughtfully, a look of sudden realization crossed Belialus's face.
"...That girl has always loved climbing mountains. It is possible she might have even ventured up Mt. Elrad."
Jin considered the possibility. In an environment where the free ether was thin, using physical reinforcement magic would be difficult, but one could likely adapt to the altitude through sheer physical exertion.
"There is also the possibility that she was found collapsed and was rescued by the Mystery Servant," Reiko suggested, offering a different perspective.
"In any case, let's investigate Mt. Elrad tomorrow."
With that decided, the group prepared for the next day.
The following morning, the Konron 2 left the ruins and moved to the northeastern side of Mt. Elrad. They reasoned that if Arshel had approached the mountain after traveling south from the demon territory, this was the most likely path she would have taken.
Lingering snow still clung to the northeastern slopes of Mt. Elrad, but it wasn't enough to impede their progress. With Belialus in the lead, followed by the Jin Double and then Reiko, they began their ascent.
The average incline was roughly twenty degrees.
Due to the low concentration of free ether, Belialus seemed to be struggling, but he kept his discomfort hidden. Driven by his resolve to find Arshel, he trudged upward in silence.
In patches where the snow had melted, plant buds were beginning to sprout, signaling the approach of spring. However, as they climbed higher, the snow deepened. Above 1,500 meters, the world was a frozen landscape of ice and snow.
"This is harder than it looks."
Though they had anticipated the difficulty while observing from the Konron 2, the reality of the trek was more grueling than imagined.
"It's no use. Let's circle around to the southern side."
On the sun-drenched southern slope, the snow was much thinner. The party traversed the mountainside until they reached the south face.
However, the incline here was far steeper. While the Jin Double and Reiko were unaffected, the lack of physical reinforcement magic was clearly taking a toll on Belialus. Despite the temperature being around five degrees Celsius, he was drenched in sweat and breathing heavily.
Watching him, the Jin Double made sure to mimic a similar level of exertion.
"Let's take a break."
The temperature on the southern side had risen to about eight degrees. Sheltered from the wind behind a large rock, it felt reasonably warm. They decided to eat some of the hardtack they had brought as rations.
Reiko didn't need to eat, but the Jin Double went through the motions. Belialus, clearly famished, ate the dry bread with obvious relish. After washing it down with some Persica juice, both his stamina and mana seemed to recover.
"Now then, where to next?"
Mt. Elrad was long from east to west, making the southern face particularly steep. Furthermore, the intense sunlight had caused significant weathering, leaving the rocks brittle and dangerous. Meanwhile, the eastern slope was still buried under heavy snow.
"Our only option is to try the western side."
Generally, when comparing eastern and western slopes with similar exposure, the western side tends to lose its snow faster because it receives direct sunlight after the day's temperature has already risen.
The group continued their traverse toward the west.
"Yeah, this looks manageable."
Unlike the eastern side, which was a wall of ice, about forty percent of the western slope consisted of exposed rock.
"Alright, let's head up."
Belialus offered no objection, and the group began a cautious ascent of the western face. They had roughly 300 meters of elevation left to cover. Jin calculated that at a pace of 100 meters per hour, they would reach the summit in three hours.
"It probably would have been faster to just land the Konron 2 on the peak," the Jin Double muttered.
Belialus shook his head. "No. There might have been clues along the way, so this wasn't a waste of time."
Since the one doing the most physical labor didn't mind, the Jin Double dropped the subject.
"Let's see... a good place to start would be..."
"How about over there?"
Following Reiko's pointing finger, the Jin Double let out a low whistle.
"A chimney, huh..."
In mountaineering terms, a "chimney" referred to a vertical fissure in a rock face. Jin had picked up the term from a television program where celebrities attempted mountain climbs.
"Climbing a chimney is always such a hassle."
The technique required bracing one's arms and legs—or sometimes one's back and legs—against opposite walls of the crack to shimmy upward.
"Jin-dono, look at this!"
While the Jin Double was preoccupied with the technical difficulties, Belialus had spotted something.
"The rock... it's been carved."
The section of the wall had clearly been modified by hand. The marks looked fresh. Upon closer inspection, the grooves formed a series of steps—or perhaps a ladder, given the steepness. Someone had intentionally cut footholds into the rock.
"They seem to continue all the way up," Belialus said, peering toward the distant summit. "I'll try this route."
"Right. Reiko and I will take another look around. If we don't find a better path, we'll follow you up."
The Jin Double and Reiko spent a few more minutes scanning the area. Utilizing Reiko's superior visual sensors, they searched for any other viable routes, but found nothing.
"I guess this really is the only way."
"Let us go."
The two followed fifteen minutes behind Belialus. Being tireless automata, they made rapid progress, catching up to him within half an hour.
"Jin-dono. It seems there truly were no other paths."
"Yeah, this looks like the only way up."
That left the looming question: who had carved this path, and why?
"It is also a mystery for whose benefit this was constructed," Reiko remarked, her voice level as she continued the climb with mechanical efficiency.
"The summit is just ahead."
Less than five minutes later, the party stood at the top. The peak of Mt. Elrad was relatively flat and spacious, though small enough to take in with a single sweep of the eyes.
"Nothing here either, I guess..."
Still, the three of them began searching for any possible clues. Then, Reiko called out.
"Please, look at this."
She was pointing at something so small it was nearly invisible to the naked eye—a tiny fragment of a gemstone.
"A ruby... maybe?"
The Jin Double picked up the fragment, which was less than half the size of a fingernail, and examined it in his palm.
"That..." Belialus's voice trembled with suppressed excitement. "That might be a piece of the ruby from Arshel's hair ornament!"