The next morning.
The true conquest of the Town of Ghosts began with a roar that rattled the very marrow of my bones.
Our objective, the Everdark Grass, grew within the tower at the heart of the town. To reach it, however, we had to clear two major obstacles: the massive gate that remained from the town's days as a prison, and the staggering horde of undead teeming behind it.
I had decided to clear out my stockpiled gunpowder by using every last bit of it in one spectacular display to demolish the gate.
"I suppose it was pointless to keep it in storage, but I may have overdone it with the quantity," I admitted.
"The dust is churning too much to see clearly, but the gate has certainly been pulverized," Sieber noted.
"Not just the gate—it looks like the undead standing right behind it were vaporized too. Not that I’m complaining," Remily added.
"It was a wise decision to keep our distance, ho-ho," Reinbach chuckled.
We peered around a corner leading to the main path while small stones rattled against the barrier I had erected just in case. Since the explosives had been intended for collapsing tunnels and burying enemies in an abandoned mine, this level of destruction was only natural.
If we lingered, the cleared space would soon be choked with undead again. We had to move while the opening lasted.
"Entrance secured," I called out.
"Gobbu!"
The goblins, who had been waiting in the rear after being deployed from my Dimension Home, charged forward in unison.
At the vanguard were armored hobgoblins hefting tower shields made from hardening fluid plates and metal slime maces. They were followed by hobgoblins with spears, another group carrying Grave Slimes, and finally the goblins equipped with long-range weapons.
Their movements were somewhat clumsy and far from a synchronized march, but they managed to seize the area in front of the shattered gate before the undead could rally. From between the ranks of the shield-bearers, the Grave Slimes were moved to the front.
Today's operation was divided into three stages, the first of which relied entirely on my tamed monsters. Even though we had cleared the entrance, the town's interior was still crawling with monsters. If the five adults and I tried to face them head-on, we would eventually be overwhelmed by sheer numbers, so I chose to balance the scales with my own army.
Even then, I had fewer than a hundred subordinates. The total enemy count was unknown, but given the town's size and the density of the miasma, Sieber estimated at least ten thousand. We were still at an overwhelming numerical disadvantage.
"Coating Light."
I cast a spell to shroud the goblins' weapons in light-attribute mana. I couldn't yet manage the "Parallel Casting of Light Ball" like Remily, but by using the metal slimes they carried—creatures with whom I shared a taming contract—as focal points, I was able to channel mana to all of them at once.
Against the undead, this alone would drastically increase their lethality, and I hoped for a synergistic effect between their numbers and the holy attribute. Once I grew more accustomed to it, I might even be able to apply strengthening magic to the goblins themselves.
Furthermore, I planned to have the Grave Slimes consume enemies as quickly as possible. This meant the goblins' actual duty was to mop up the stragglers that managed to bypass the slimes. By letting them focus solely on that while providing support from the rear, even the goblins should be able to maintain the upper hand.
Should the situation deteriorate, the adults or I would step in to stabilize the line, though I expected that would only be necessary for the first few hours. Once the Grave Slimes began multiplying as they fed, our processing efficiency would skyrocket.
It was helpful to think of today’s mission as a "Territory Game," where we would steadily expand our foothold into the Town of Ghosts as the Grave Slimes grew in number.
"Holy Space. I’ve finished setting up the resting area on this side as well," Remily announced. "This is going to be a war of attrition, so take it slow. If you feel tired, fall back early."
"Thank you, I’ll be careful," I replied.
As we spoke, the first waves of undead emerged from the town's depths, approaching step by step. Since the sun was already up, they moved at a crawl. However, the sight of an army so vast its end was invisible, combined with the collective sound of dragging feet and low moans, exerted a chilling pressure.
"Gogo..."
"Guuu..."
The goblins felt it too. I could sense the anxiety blooming in them as they faced the massive horde. If they lost their nerve now, the battle would be lost before it truly began.
I needed to give them a morale boost by showing them how easily these enemies could be destroyed. Conveniently, the vanguard consisted of Wraiths. Because they were airborne, they weren't bogged down by the terrestrial undead, giving them high mobility.
"Long-range attack unit, ready!"
They were fast, but they were also vulnerable in the open air without cover. Furthermore, the "Undead Attraction" skill was drawing them in a straight line toward the Grave Slimes. They were effectively huddling together into a perfect target.
At my signal, the goblins in the rear raised the slingshots attached to their arms. These weren't toys; I had modeled them after heavy-duty hunting slingshots, utilizing metal frames to brace the arm for accuracy and allowing for a much higher draw weight. Naturally, the elastic was made of Rubber Slimes.
"Wait for it... Fire!"
The goblins loosed their projectiles in a single volley. The stones flew in a high arc, raining down on the Wraiths who were fixated on the Grave Slimes. The moment the stones struck, they tore massive holes through the spirits, causing them to dissipate instantly.
The ammunition consisted of small stones processed from nearby rock walls, roughly the size of BB pellets. I had coated them in light-attribute mana, which provided more than enough power. In a fight against the undead, the weight of a weapon mattered far less than the presence of mana. If you could imbue an object with the holy attribute, almost anything became a lethal weapon.
"Gogo!?"
"With weapons imbued with light, these undead are nothing! Stay in formation and keep your heads, and that horde is no match for you!" I shouted.
"Go, gooooo!!"
"Keep firing at anything within range! We have plenty of ammunition!"
"Gooooo!"
Seeing the undead fall so easily was the ultimate proof. The goblins' hesitation vanished, replaced by visible excitement.
Seeing them raise their voices in high spirits, I felt a wave of relief. Beside me, Sieber gave a nod of approval.
"You handled their morale well."
"Thank you. It was also a good chance to confirm the effectiveness of the gear. I don't think the front line will collapse easily now. But until we actually enter the town buildings, the Wraiths shouldn't be able to phase through the canyon walls and flank us, right?"
"Correct," Sieber confirmed. "They can pass through man-made walls, but natural terrain—bedrock and soil—stops them cold. Lacking physical bodies, Wraiths are more sensitive to environmental mana; the natural energy of the world effectively crushes the mana that forms their being. That is also why they rarely appear outdoors during the day compared to zombies or skeletons."
"I see."
"They've only come out now because of that massive explosion near a high-miasma zone. Under normal circumstances, you wouldn't see them outside while the sun is up. There are even accounts of people luring them into the open and blocking their path back inside, causing them to simply evaporate after a few hours of exposure. They are that fragile when it comes to mana."
"That much, huh?" I wondered if they could be defeated by focusing sunlight with a magnifying glass. The light magic Remily used yesterday involved focusing mana-generated light; I remembered seeing videos of solar cookers or people grilling meat with mirrors in my old world. It seemed plausible that one could kill undead without magic using the same principles.
"Oh? Ryoma-chan, look at that," Remily said, pointing her staff toward the ground.
The terrestrial undead were struggling to advance. Some of the zombies and skeletons had tripped, causing those behind them to stumble and create a massive pile-up. The ones who fell were quickly trampled into the dirt by the following ranks.
"Are they tripping on the stones we just fired?" I asked.
"It looks like it. The mana must have remained in the stones even after they pierced the Wraiths. It’s helping us, so I’m not complaining, but exactly how much mana did you pack into those little pellets?"
"I don't know the precise numerical amount," I replied.
The production process had three steps: first, I extracted stones from the cliff using earth magic. Then, Stone Slimes ate them and detached uniform pieces of their bodies to standardize the size and shape. Finally, Light Slimes took the stones into their bodies to apply the mana coating.
"Since the Light Slimes handled the final stage, the exact amount was up to them. However, since I made the initial sample for them to copy, it should be roughly equivalent to one explosive Light Shot. In numerical terms, maybe around 10?"
"If the amount of mana is the same, then the difference is pure efficiency. It’s natural for an expert to get better results than a novice with the same spell. But... are slimes really that proficient at magic?"
"I think they're exceptionally good at handling mana. In my experience, they never waste a drop of it when casting."
"Fascinating. I’d like to observe them properly once we’ve settled down. By the way, is that really how those stones are made? I thought a slime’s body disappeared when it died."
"That’s true for normal slimes," I explained. "Their bodies are composed of mana, so death causes them to dissipate. However, for high-tier species, it's common for them to secrete fluids or produce solid materials. My theory is that as they evolve, their mana undergoes a change, gaining physical permanence. It’s similar to how water magic creates actual water out of mana. The Stone Slimes detach parts of their bodies and then replenish that lost mana by consuming natural stones."
"Slimes aren't my field, but that's a sound magical theory... So they eat rocks to recover the mana they 'spent' to create the pellets."
"Exactly. If they are forced to produce without being fed, they become visibly weakened."
I didn't know the exact biological mechanism yet, but I felt my hypothesis was heading in the right direction.
"I’ve used the same logic to have Iron Slimes eat iron ore to produce iron."
"Ryoma-sama, could that be used for large-scale iron production?" Sebas asked, his eyes wide.
"In theory, yes. But practically, it's difficult."
"And why is that?"
"Inefficiency. When a slime processes material this way, the output is significantly less than the input. I need more research to be sure, but my experiments showed that we lose at least thirty percent of the iron content found in the ore. Sometimes as much as fifty percent is consumed as 'food' by the slime."
For worthless stones, it didn't matter, but for a commercial iron foundry, that was a deal-breaker.
"We could probably increase the yield if we didn't care about the slime's health, or perhaps find a more efficient feeding method. But even then, 'iron' varies in quality and hardness based on its trace components. We don't know yet what this slime-produced iron is best suited for. It’s a long way from being a viable industry."
"That is a reasonable assessment," Sebas conceded.
Personally, I didn't think we had to eliminate that consumption entirely. In the world of distilling, there’s a term called the "Angel's Share" for the portion of alcohol that evaporates during maturation. If that was the case, I figured the missing iron could simply be the "Slime's Share." From a strictly commercial standpoint, it was a waste of profit, but I preferred to accept it as a fair trade for the slime's hard work.
Existing iron-making technology was already well-established, and I wasn't obsessed enough with profit to try and squeeze my slimes for more. I was interested from a research perspective, but it was low on my priority list. Honestly, my list of things to study regarding slimes was already becoming unmanageable.
Having the goblins provided more "hands" for labor, but with only one person—me—to give them orders, there were still limits to what we could achieve.
"Here they come! Shields!" I commanded.
The first wave of the horde finally reached our line. The undead were being sucked into the Grave Slimes one after another, but they had no concept of patience. They shoved and clawed at each other, desperate to dive into the slimes' predatory reach.
The stragglers who were pushed out of the main cluster were met with force.
"Goaaaa!!"
"Gigii!"
The hobgoblins in the front row braced their tower shields, catching the undead and shoving them back like train conductors cramming commuters into a subway car during the morning rush. Between the shields and the spears, the situation remained stable enough for me to keep my composure.
I couldn't afford to be careless—there might be higher-ranking undead mixed in—but for now, we just had to hold the line.
"I wonder if we’ll actually get a turn? Those goblins are more formidable than I expected," Reinbach noted.
"When someone with as much mana as Ryoma-sama focuses entirely on support, it's a nightmare for any enemy, undead or otherwise," Sebas remarked.
"True enough," Remily added. "Ryoma-chan usually prefers to be in the thick of it, but this is a vital lesson. Learning to adapt your fighting style to the situation is a skill every great mage needs."
"He’ll likely have to lead others in the future," Sieber said. "Though the goblins' discipline could use some work. They're doing well, but with proper training, they could perform much more complex maneuvers. Those shield-bearers, for instance—they need to brace with their weight, not just their arms."
The veterans, having seen enough to know the situation was under control, had already settled into observation mode. Under their watchful eyes, we continued our grueling task of thinning the endless tide of undead until the sun reached its zenith.