The entrance to the Whitefall Grotto was less impressive than I'd imagined. A yawning mouth in a limestone cliff face, about three meters high and twice as wide, with crude wooden scaffolding reinforcing the edges. A bored-looking guild guard sat on a stool nearby, checking adventurer medallions with the weary air of someone performing the same task for the thousandth time.
"WF-0097, huh? Fresh meat," he grunted, glancing at my copper medallion. "Stick to the marked paths. Don't go past the third chamber unless you're with a party. And watch for cave slimes—they've been breeding in the runoff tunnels."
I nodded, adjusting the strap of my pack. Inside were basic supplies: torches, chalk for marking, a waterskin, dried rations, and the simple mapping tools I'd purchased with my last few coppers. My iron sword hung at my hip, and I'd spent the previous evening carefully applying a thin layer of Weapon Enhancement (E) to it, hoping the temporary boost might matter.
Taking a deep breath, I stepped into the cave.
The temperature dropped immediately. The damp, mineral-rich air filled my lungs. Sunlight faded within twenty paces, replaced by the faint, magical glow of lumen moss cultivated along the ceiling—the guild's basic safety measure. I ignited one of my torches anyway; the flickering flame was comforting.
I activated Mana Eyes (E).
The cave transformed. The grey limestone walls now pulsed with faint, earthy yellow mana veins. The lumen moss glowed with a soft blue-white light. The air itself swirled with drifting mana particles, thicker in some areas than others. More importantly, I could see the residual mana trails of previous adventurers—fading footprints of various elemental types, most leading straight down the main tunnel.
"Start with the obvious," I murmured to myself, pulling out my map sheet.
The first hour was tedious work. The main tunnel branched twice, both side passages clearly marked with guild symbols and well-traveled. I mapped them anyway, measuring paces, noting rock formations and notable features. My Fivefold Senses helped immensely—I could hear distant dripping water that hinted at unseen chambers, and my enhanced touch felt subtle air currents moving through cracks in the rock.
According to the novel's fragmentary description, the hidden chamber wasn't in an obvious side passage. It was accessed through what appeared to be a solid wall in a specific secondary chamber—the "Pool Room"—during a specific lunar phase when the mana alignment in the cave created a temporary resonance.
I found the Pool Room after another thirty minutes. It was a circular chamber about fifteen meters across, with a shallow, still pool of groundwater at its center that reflected the lumen moss above. A few other adventurers were there—a pair of tired-looking scouts taking measurements, and a trio of fighters washing grime off their armor.
Keeping my Mana Eyes active, I began my survey. The novel mentioned the western wall. I walked along it, my eyes scanning not just the physical rock, but the mana flow within it. The wall looked solid, but mana didn't lie. In most of the cave, the earthy yellow mana flowed in consistent, horizontal strata. Here, near a particular, unremarkable section of the wall, the mana swirled. It formed a faint, almost invisible vertical pattern, like a subtle eddy in a stream.
There.
I marked the spot mentally. According to my calculations based on the novel's clues, the resonance would occur at night, during the waning gibbous moon. That was three days from now.
"Find anything interesting, mapper?"
I turned. One of the fighters, a woman with a scar across her cheek and a well-used axe on her back, was watching me curiously.
"Just checking the rock composition," I said, keeping my voice neutral. "The guild wants accurate mineral surveys for the alchemists' guild."
She snorted. "Rather you than me. Boring work." She and her companions gathered their gear and headed out, leaving me alone with the two scouts, who soon also departed.
Alone, I risked a closer examination. I placed my hand against the cool stone of the swirling mana section. Closing my eyes, I pushed a tiny thread of my own mana into it, using Mana Control (D) with surgeon-like precision.
The rock drank the mana. Not greedily, but with a passive acceptance, like dry soil absorbing a drop of water. More importantly, the mana didn't dissipate. It traveled. I could feel it moving through the stone along that swirling pattern, deep into the mountain.
A hidden channel. A mana lock.
My heart beat faster. The novel was right. This was it.
A soft, wet plopping sound from behind me broke my concentration.
I turned, my hand dropping to my sword.
At the edge of the pool, three gelatinous, translucent blue masses were oozing their way onto the stone floor. Cave Slimes. F-rank monsters. Individually, they were only dangerous to the completely unprepared—their acidic bodies could burn skin and cheap leather. In numbers, they could be troublesome.
These three had likely been drawn by the mana I'd just emitted. Slimes were attracted to energy sources.
"Perfect," I muttered. I needed combat data anyway.
I drew my sword. The first slime lunged with surprising speed, a pseudopod forming and whipping toward my leg.
I didn't use Roy's Swordsmanship. This wasn't a test of my hybrid art. This was a test of efficiency. I sidestepped and used a simple, clean thrust from the Imperial Swordsmanship, enhanced by Physical Enhancement (E). My blade pierced the slime's core.
The creature quivered and dissolved into a puddle of harmless blue goo. One silver coin—a condensed monster core—plinked to the stone floor.
The other two slimes attacked in unison. I backed up, gauging their movement. Instead of attacking directly, I focused on the ground at their path.
"[Plant Creation (G)]."
I wasn't trying to grow a tree in a cave. I focused on the microscopic spores and algae in the damp stone. At the slimes' leading edges, the stone suddenly became gritty and coarse. A patch of tough, fibrous lichen erupted from the surface, tangling the slimes' gelatinous bodies.
They slowed, confused. That was all the opening I needed.
Two more precise thrusts. Two more puddles. Two more silver coins.
I sheathed my sword, breathing steadily. The fights were trivial, but informative. My physical stats at E-rank made F-rank monsters non-threatening if I kept my head. My mana use was efficient—the Plant Creation trick had cost barely a wisp of energy, but had created an effective battlefield control effect. That was the true potential of my element: not raw power, but manipulation.
I collected the three silver coins—my first adventurer income. As I stood, I noticed something. With my Mana Eyes still active, I looked at the puddles of slime residue. They were fading, but their mana—a dull, watery blue—was seeping into the stone floor, and faint trails of it were being drawn toward the same western wall with the hidden channel.
The slimes' innate mana was being absorbed by the cave. By the lock.
An idea sparked. What if the "key" wasn't just waiting for the right moon? What if it needed a certain type or amount of mana to be introduced into the system?
The novel's protagonist had stumbled in during the right phase, his own potent lightning mana accidentally triggering the resonance. My Plant mana was different. But what if I could... feed the lock?
It was a dangerous theory. Tampering with unknown magical mechanisms could backfire spectacularly. But I had three days until the lunar phase. Time to experiment.
I spent the next two hours finishing the basic mapping of the assigned areas, earning my 5 silver cartography fee. But my real work began as I left the grotto at dusk.
I needed information. I needed to know exactly what kind of mana the cave system naturally held, and what the slimes' mana properties were. I needed to study the lunar phase's effect on ambient mana. And I needed to do it without drawing attention.
As I walked back to Whitefall, the copper medallion of WF-0097 felt a little heavier, a little more real. I wasn't just mapping caves.
I was learning to listen to the whispers of the world's magic. And I was planning my first real heist.