A Deserted Mine Shaft.

While the festival was actively in full swing back on the fifth floor, our party had executed a descent to set foot onto a brand-new stratum.

The ninth subterranean floor completely flipped the script, instantly projecting a highly artificial atmosphere. Unlike the eighth floor—which had been overflowing with a vibrant palette of colors anchored by lush greens—the overall color scheme here was entirely drab, dominated by subdued browns and grays.

The structural space directly beneath the staircase formed a tiny plaza, its walls and floors comprehensively clad in square-cut blocks of stone. Although the masonry bore the distinct weathering of age, the blocks were fitted so seamlessly that not a single finger could wedge into the joints. Its structural durability felt entirely reliable.

However, a barrage of branching passages systematically webbed outward from this hub. In those corridors, the raw earth and jagged stone were completely exposed. While wooden frameworks routinely braced the ceiling at various intervals, the sheer degree of discoloration rotting the pillars left me with absolutely zero desire to trust their stability.

Our light sources consisted of scattered, faintly glowing glow-stones, but the raw lumen output was so terribly deficient that we could barely calculate the contours of the path a mere few steps ahead.

“Ugh… we’re in another incredibly shady-looking zone, aren’t we~?”

“Shady~!”

“Kyuu.”

“This place honestly looks like the wreckage of an abandoned mine shaft…” I murmured.

If my memory served me right, those wooden reinforcements were a textbook example of mine timbers. The drifting atmosphere felt chilled and damp against the skin, carrying a highly cryptic, indescribable stench. When I tested the corridor walls with my hand, the rock felt surprisingly solid; it wouldn’t easily flake away even if I locked raw force into my fingertips.

“Well, at the very least, it doesn’t look like we need to fret about an immediate cave-in boundary. Paula, Ethan, do either of you calculate any specific hazards we should maintain absolute vigilance against?”

“No… I register nothing out of the ordinary…” Paula replied.

“The same applies to me. However, I calculate it would be a hundred times safer to allow everyone’s vision a brief window of opportunity to adjust to the dark before pressing forward,” Ethan advised.

Following Ethan’s tactical counsel, I fitted a canvas cover over our glow-stone lantern and instructed the fairies to tuck themselves away beneath my clothing for the time being.

While the rest of us stood completely frozen to let our eyes adapt, Yoru and Kuu—the only units blessed with flawless night vision—were bounding around with an immense volume of energy. They clearly calculated that our temporary immobility was a magnificent source of amusement. They went completely wild, launching unprovoked airborne leaps straight onto Mia and Paula’s backs, or locking their limbs in a tight hug around my leg. Whenever I managed to snare them and initiate a barrage of tickles, they would unleash a chorus of tiny giggles and scurry away into the gloom.

Once the two entities had completely exhausted their play parameters and everyone’s vision had comfortably adjusted to the dark, we initiated our advance down the passage stretching toward the northeast.

The corridor was surprisingly devoid of winding curves, meaning our structural line of sight wasn’t terrible at all. Or so I calculated—right up until the exact fraction of a second we breached the perimeter of a four-way intersection, where a sudden disaster unfolded.

A cryptic, pitch-black shadow shot like a missile out from one of the intersecting side passages, launching a ferocious assault straight at the individual holding the glow-stone lantern. A thunderous kinetic impact vibrated loops through the corridor, and without losing a single shred of momentum, the rounded shadow cruised straight past and vanished into the gloom.

Left in the wake of the blitz was our lantern rolling clumsily across the stone floor, intersecting with the completely pulverized, scattered fragments of a skeleton wolf’s bones.

Right… rest in peace, Bone-ko-chan. Thank you for your flawless sacrifice in the line of duty.

Positioned roughly ten steps back from the impact zone, our party began whispering to analyze the immediate situation.

“Did either of you catch its physical vectors?”

“Yes. To think a creature operating on such a bizarre paradigm resides down here… Yeah, this stratum is undeniably magnificent,” Ethan noted, a soft smile playing on his face.

“How about you two? Do you calculate you can handle its speed?”

“I am terribly sorry… My whip won’t possess the proper compatibility threshold to bypass its defenses,” Paula murmured, downcast.

“I managed to track it right at the absolute limit of my vision, but its velocity parameter is pure insanity! Totally impossible for me!” Mia cried.

Well, her signature spell strictly traveled at the casual velocity of a lightly tossed ball, after all.

Since Ethan verified that he was perfectly fine to engage, we resolved to execute a precise reconstruction of the previous event. I jingled my Underworld Summoning Bell to reset and resurrect Bone-ko-chan.

The exact dynamic fraction of a second the reassembled skeleton crouched down and extended its hand to retrieve the glow-stone lantern, the pitch-black shadow rocketed out from the side corridor once more. But in that identical split second, an arrow that had already broken free from Ethan’s bowstring slammed directly into the absolute center of the intersection.

The violent crunch of splintering bone intersected with a metallic, high-pitched clang as steel ground against carapace. Having effortlessly deflected the incoming arrow, the rounded mass crossed the hallway and vanished into the opposite corridor without slowing down.

“So close! That was a flawless hit, too!”

“No, everything is completely fine, Mia-chan,” Ethan replied with a gentle smile, his gaze anchored on the discarded arrow on the floor.

Peeking closer, the arrowhead that was supposed to anchor the tip of the shaft was entirely missing.

Securing his confident nod, I jingled my bell once more to call forth my skeletal servant. This time, when I had it lift the lantern, zero hostile responses registered. We waited around for roughly a full minute to verify the safety parameters of the zone, before I softly peeked around the corner of the passage.

The side corridors forming the crossroad both terminated into absolute dead ends a mere few steps out. Huddled tightly against the far wall of one cul-de-sac was the coiled, pitch-black hostile.

Its overall structural form was comprehensively rounded. However, packed in dense, suffocating clusters across its exposed underbelly were an infinite number of short, wriggling legs.

Yeah… to state the absolute, unvarnished reality: resting right there was a flipped-over, basketball-sized pill bug.

Faced with a visual that so aggressively triggered a wave of pure physiological revulsion, Mia caught her breath and unleashed a tiny shriek.

“Yuck! That is comprehensively disgusting!”

“If my data is correct… that entity is a certified Iron Beetle,” I noted. “To put it bluntly, it’s an exceptionally dense, ironclad pill bug.”

Because its biological lifestyle relied on consuming ore heavily saturated with iron, its outer carapace possessed an immense metallic density, making it a comprehensively sturdy monster. Its signature talent was the textbook maneuver. Under normal navigation parameters, its mobility was incredibly sluggish—but the exact fraction of a second it rolled its frame into a sphere, its velocity and physical defense metrics underwent an exponential escalation.

“What are your directional orders, My Lord?” Paula asked.

“Hmm… we already have Blue Slime active in our roster, so I calculate this unit is entirely redundant.” I mean, even if we went through the trouble of bringing it along, its aesthetic parameters were far too terrible.

The exact fraction of a second the response left my lips, Ethan casually let his bowstring sing. Operating in a flawless, rapid-fire sequence, three successive arrows pierced clean through the pill bug’s defenseless underbelly. The creature’s grotesque legs ceased their twitching movements instantly.

As I stood there thoroughly blindsided by his hyper-efficient tactical response, the hunter walked briskly over to the carcass and retrieved his arrows in a single heartbeat. Moving with highly deliberate precision, he extracted a Forest Crow Talon arrowhead that had buried itself deep into the side flank of the construct.

During that single, blink-and-you-miss-it split second where the Iron Beetle had blitzed across the intersection, he had masterfully mapped his shot to pierce the exact micro-quadrant completely unprotected by its carapace. Good grief… his dynamic visual acuity and archery precision operate on a truly terrifying plane, I reflected.

“Spectacular~!”

“Kyuuu~!”

Highly eager to validate his magnificent feat, the two little entities scurried over and began casually patting Ethan’s leg. The young man of the Treant race gently narrowed his eyes, his features softening at their adorable display. When every single unit in this party is this cute, it becomes a major administrative hazard, I mused.

Having successfully harvested the Iron Beetle’s metallic carapace and a yellow magic stone, we once again assigned Bone-ko-chan to operate as our decoy vanguard and resumed our advance.

These hostiles appeared to selectively manifest at major corridor junctions; once you successfully calculated their behavioral loops, they weren’t a frightening threat at all. Occasionally, they would deploy in small clusters, but since their systems possessed a terrible resistance threshold against magic, applications like or yielded maximum efficiency, ensuring our progression encountered zero friction.

After a steady march of roughly fifteen minutes, we hit a definitive dead end and shifted our directional vector toward the west. I calculated that this entire stratum might possess a remarkably small geographical footprint.

The moment we transitioned into the western sector, the pill bugs completely ceased their manifestations.

Our party pressed forward in absolute silence through the cavernous gloom of the mine shaft. Roughly five minutes must have elapsed when a cryptic shape suddenly materialized within the illumination zone of Bone-ko-chan’s lantern.

The entity stood perfectly erect on two feet, mimicking our exact posture. Its physical silhouette was a textbook match for a human being. Its body—entirely devoid of fur and leaving its bare skin completely exposed—approximated the structural mass of a ten-year-old child. In a barrage of diverse ways, it shared an immense number of common points with us.

However, there existed a single, cataclysmic divergence.

Its head.

Anchored squarely onto its shoulders was the colossal, twitching face of a rat.

“Ugh… w-what on earth is that thing? Isn’t that boundary completely psycho?…”