Chapter 118

It is well known that underground caves do not spontaneously produce glass. Deep-dwelling creatures are unlikely to be able to fire pottery, so these items must have come from humans—and very likely not from local villagers.

Kraft discarded the small shards of glass, put on gloves, and cleared away the mixture of dust and broken stones, retrieving larger surviving fragments.

They appeared to be thick, rounded bases of cups or bottles, with clear signs of artificial firing; the craftsmanship was inferior to Vetchum’s, but after wiping off the grime, their relatively good transparency became visible—light easily passed through the one-finger-thick walls, casting irregular patches caused by uneven melting.

He unslung his scabbard and used its tip to pry apart the shards of the large pottery vessel, revealing a residue clinging to the inner walls, ranging between yellow-brown and reddish-brown.

He pinched a bit of it and detected the scent of old metal objects that had lost their oil film—poorly handled, left damp too long, and ultimately ruined.

The residue cracked and flaked like slightly damp flour under light pressure, dispersing into dust-like particles, some inevitably drawn into his nostrils—a metallic, rust-like stench carrying a faint, lingering sourness.

The uneven granular particles resembled common rock, typical slag deposits left behind after incomplete mineral calcination.

“Rust powder?” Under Kraft’s threatening gaze, William stopped tasting it, but that didn’t stop him from recognizing what it was—he often rubbed it off old iron parts in the cabin.

As for why someone would grind iron rust into powder, the captain had no idea, but the rust powder reminded him where he’d seen these green minerals before: “I remember—I’ve seen these green things before, but not like this. They were ground into powder and mixed into ink, given to me for drawing parchment sea charts.”

“You actually recognize it?”

“It tastes peculiar—kind of like iron rust and red iron ore.” William licked his lips, savoring it. Perhaps due to an instinctive wariness of injury, this peculiar taste—akin to biting one’s lip and drawing blood—was easily memorable. “Any ideas?”

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Kraft was using his meager chemical knowledge to analyze the pile of debris. Unfortunately, due to changes in the exam format back then, this otherworldly soul had never deeply studied chemistry; even medical chemistry had been barely touched, his level equivalent to that of a middle school student.

Still, it wasn’t entirely useless—he could roughly guess it was some kind of iron salt, likely turning into rust when calcined—no, he meant iron oxide.

“I have two pieces of news.”

“Another good and bad one?” William showed remarkable resilience—or rather, compared to what he’d endured before, this hardly mattered. “I don’t want to choose. Just give me one.”

“We’re inside the alchemist’s mine.” Kraft picked up a green crystal fragment broken off from a raw stone, crudely snapped at its base and piled beside the apparatus for easy access. “We’ve figured out our target isn’t some unique rare mineral—it was already used in ink.”

The green crystal’s appearance strongly suggested ferrous ions; given the product was sulfuric acid, it likely contained sulfur anions, possibly with added water to form crystals.

Case solved—it seems to be primitive dry distillation, collecting heated byproducts to obtain sulfuric acid.

Congratulations to this talented amateur chemist: journeying to remote, desolate lands, he discovered a beautiful mineral long since known, and under the guiding principle of “extracting the essence of ore,” accidentally stumbled upon dry distillation, ultimately producing sulfuric acid—and killing himself.

Out of secrecy, or perhaps genuine ignorance that such substances existed elsewhere—used only in tiny quantities and supplied as powder—he insisted on mining in a human geography nearly completely isolated from the outside world.

This made information leakage extremely difficult. With strict control over key personnel, reverse tracing from outside to inside became impossible, directly causing the technology—and the man—to vanish together.

This prematurely aborted invention would have been buried forever with its creator and the terrifying cause of his death, until one day someone, bored out of their mind, tossed some ink ingredient into a distillation flask to play with.

Then a clever bastard dug up clues from a stroke victim, traveled thousands of miles to arrive here, and just happened to catch the final wave of misfortune years after the accident.

It felt like finding a treasure map that led to a crooked tree at the entrance of your own village.

“We don’t need to risk developing this mine at all. We just need to go back and find out where this stuff is produced. It’s absurdly simple.”

William froze for a moment. The green glow that had seemed worthless just minutes ago now seemed to shift, gilded with a bright golden edge. “You said you had two pieces of news. What’s the bad one?”

“The one I just told you was the bad one.”

“Huh?”

“We’re inside the alchemist’s mine for extracting raw materials.” Kraft repeated the fact, slipped the crystal into his pocket, and lit another torch as he walked forward. “I hope you still remember what happened in this mine—or would calling it the ‘Old Mine’ help jog your memory?”

They stepped over pottery shards and glass fragments, crossed the broken-handled pickaxe, and saw chisel marks on the cave walls. William quickly realized what their greatest problem was.

“Collapse…”

In the area with the densest mining traces, the entire section had caved in, blocking the passage with rocks. The arrival of the excavators wasn’t the direct cause of the miners’ deaths, but it delivered the fatal blow to the already weakened structure.

On the massive boulder blocking their path, chisel marks converged into several small pits. A rusted iron pickaxe, its head broken off, lay discarded nearby.

“Can we try going back and finding another route?”

Kraft slowly shook his head, lighting another torch—he’d brought plenty, but they wouldn’t last forever. “We probably don’t have time to find a second path.”

“So close… just a little further?” William shoved the rock with all his strength, recoiling several steps from the recoil. The rock didn’t budge. After traveling so far, escaping from that monstrous thing, standing inside the treasure they sought—only to be blocked at the final step?

They were likely no more than a few dozen steps from the outside world. The collapsed rocks had turned this stretch into an impassable chasm—impossible to dig through by human strength alone.

“Are those things going to add two more faces now?” Repeated cycles of hope and despair had battered the captain. They were truly at their wit’s end now—Kraft’s “magic” might carry them across layers, but it couldn’t magically carve a new path.

Kraft remained silent. If anyone felt regret, it was him more than William. Beyond the desire to return and tell stories, he had half a person’s height worth of writing unfinished—he didn’t want to spend his final days in the depths, sharing space with arthropods and shelled worms.

But this wasn’t a problem he could solve. Unless he could conjure up a tunnel boring machine, how could he possibly dig through over ten meters of rock?

“We haven’t seen a single bone—probably all dragged away by those things…” William picked up a heavy piece of feldspar and tried swinging it. He seemed determined to make one final, dignified stand.

That made sense. Along the way, they’d only seen alchemical equipment and pickaxes. Coupled with the local faces that had surfaced in their minds, it wasn’t hard to guess what had happened to the victims.

【Tunnel boring machine?】

Kraft rubbed his chin, his mind suddenly sparked with a dangerous idea—he realized this might not be pure fantasy after all.