The cave-in that occurred at the aluminum oxide mine in Torom, within the Shouro Empire.
It was highly likely an artificial incident caused by foul play—in other words, sabotage—and the Shouro Empire's intelligence operatives had mobilized to investigate.
Among them was Quinta Unit Regulus 45 under Laojun, operating under the alias Landgeek.
Landgeek was a mid-tier operative among the field investigators—the underlings who actually ran around pounding the pavement—maintaining an unexceptional record that was neither remarkably good nor bad.
A total of ten intelligence operatives had been deployed.
They were currently holding a briefing at their temporary headquarters.
This temporary headquarters was set up in a rented vacant house on the outskirts of the town of Torom.
Outwardly, it served as the Torom Mine Cave-In Countermeasures Headquarters.
Actual personnel assigned to review the maintenance and management of the tunnels were also present, so on paper, there were no issues whatsoever.
"Now then, since we've completed our initial sweep, let's hear everyone's reports. Starting with No. 1 and No. 2."
The leader of the intelligence operatives spoke. For this operation, he went by No. 0 for convenience. The remaining members were naturally designated No. 1 through No. 9. Regulus 45 was No. 9.
They typically operated in pairs. This time, No. 1 took the floor.
"Yes, sir. No. 2 and I inspected Tunnels 1, 2, and 3, which remained intact. As a result, we found several micro-class scratches similar to those on the reinforcement timbers in the collapsed shafts."
"Hmm, just as suspected."
It seemed the collapsed Tunnels 4 and 5 had not been the only targets.
"The scratches were located roughly forty centimeters from the ground, virtually identical to what we observed in the collapsed tunnels."
"Which means they were placed somewhere hard to notice."
Marks left at eye level would be spotted immediately, but lower down, they could easily be overlooked.
Since there was nothing else to report, it was next the turn of No. 3 and No. 4.
"We investigated the collapsed Tunnel 4. In doing so, we found this....Hey."
Following No. 3's cue, No. 4 set a small vial on the table.
"What's this?"
"Animal hair. We discovered it deep inside Tunnel 4."
He noted that what raised their suspicions was finding it so deep within a tunnel where no wildlife should naturally dwell.
"Naturally, it isn't human hair. We ran a brief check on it, and it closely matches that of a Rock Wolf."
A Rock Wolf was a carnivorous predator rather than a magical beast. With a body length of roughly one meter, it would be entirely capable of leaving scratches at a height of about forty centimeters. In fact, that was the most natural assumption.
However, Rock Wolves inhabited the northern forests and possessed no behavioral tendency to venture deep into subterranean caverns.
"We found no traces of droppings or remains of prey."
With that, No. 3 and No. 4 concluded their report.
"Then it's our turn."
No. 5 and No. 6 began their report, with No. 6 taking the lead.
"The two of us investigated Tunnel 5. It suffered a collapse as well, but the shaft has now been cleared and secured, so there appears to be no immediate danger. And what we found was likewise..."
No. 5 placed another small vial onto the table.
"...animal hair."
Here, too, was hair believed to belong to a Rock Wolf.
And furthermore...
"By pure coincidence, we also found a footprint."
No. 5 laid a sketch upon the table.
"It's drawn to scale."
It was unmistakably that of a Rock Wolf.
"However, there were no traces of actual habitation... if you will, such as droppings or leftover food," he concluded.
Then came the turn of No. 7, No. 8, and No. 9, who had been operating as a trio.
"We conducted a sweep of the surrounding perimeter," No. 7 spoke up as their representative. "Though time had passed and they were starting to fade, we found several Rock Wolf tracks."
He explained that the prints had been left in damp mud.
"However, while there appeared to be tracks from multiple animals, a close examination of the imprint revealed only a single unique foot shape. As for how to interpret this..."
He raised the possibility that a single wolf had paced back and forth repeatedly, adding:
"...there is also the possibility that they all possessed the exact same foot shape."
Such was the conclusion he offered.
"The exact same foot shape? Stop dancing around it and speak plainly," No. 0 said, his irritation showing.
"...It means they were artificial Rock Wolves."
At those words, half the room smiled wryly, while the other half grimaced.
"Is there anyone even capable of pulling off something like that...?"
A few operatives swallowed their words mid-sentence.
They had all just thought of someone who fit that description.
"No, it was neither the Magi Craft Meister nor Lord Deus Ex Machina," No. 9—Regulus 45—stated with absolute certainty. "The craftsmanship is far too crude."
"...How can you be so sure? No, I'm not accusing the Magi Craft Meister or Lord Deus Ex Machina, I'm asking out of genuine curiosity."
"It is quite simple. There is no way two individuals of their caliber would possess such clumsy technique that their work could be identified as artificial from a mere footprint."
"Fair point."
With that explanation, the room seemed satisfied for the time being.
"Besides," Regulus 45 continued, "neither of them has a motive."
Causing a mine to cave in offered them nothing to gain.
"Furthermore, both of them actively participated in rescue operations when the disaster struck."
"True enough....No, to reiterate, I wasn't suspecting them. I was merely curious what grounds you had for dismissing them so readily, No. 9."
No. 0's expression turned stern once more.
"Now then, while we've established that artificial Rock Wolves were likely the cause of the cave-in, that is merely our first lead on the real culprit. We still have a long road ahead of us. Everyone, stay sharp and proceed with caution."
"Understood."
The details of the meeting were relayed straight to Laojun through the eyes and ears of Regulus 45.
I see. Artificial Rock Wolves. Judging by the traces left behind, they must be crude work indeed. Even so, there is no question this surpasses the modern technological standard. Just who could be behind this...?
Laojun, too, had grown intensely curious about the mastermind's true identity.
Even if we search the perimeter now, there may be nothing left to find, but still...
Deploying a Peeper, Laojun initiated a meticulous scan of the surrounding area.
Around the same time, inside the laboratory on Hourai Island...
"Mm-hmm! Using this asphalt emulsion like this is definitely the best approach!"
Having steadily pursued her experiments, Saki had finally reached a tentative conclusion.
Even while juggling the production of masks made from non-woven fabric, she pursued her research with sheer delight, yielding satisfying results on both fronts.
"Kufu, I can't wait for Jin to get back."
"Good work, Saki-nee."
Elsa, who had stayed behind on Hourai Island this time, offered her warm praise.
"You helped me out a lot too, Elsa. I should be thanking you."
"Mm. I think Jin-nii will be back tomorrow."
Given the substantial time difference with the Shouro Empire, it was inevitable.
Though it had been a frantic rush of research, the fruits of their labor were steadily taking shape.