The underground waterway was far more massive and solidly constructed than I had imagined. The ceilings were high, and the sense of confinement was surprisingly minimal. Most unexpected of all, however, was the complete lack of any foul odor. Even the wastewater looked clear at first glance. And there was a good reason for that: the sewage flowing through these tunnels was purified by Clean magic. Magic tools were installed in various sections to trigger the spell automatically, cleaning the runoff from the surface in several stages as it passed through. It was the kind of infrastructure you could only find in a world with magic.
Halfa, guided by her Oracle, seemed to know exactly which sections led to the deeper parts of the dungeon. Our formation had Glory's Steps in the lead, followed by Zephyr and his group, with the party known as Evil-Dispelling Sword bringing up the rear.
Our progress was steady—at least, until we reached the midway point.
A sudden splash echoed from behind us. In a waterway currently undergoing dungeonification, any presence emerging from the water could only be a monster.
I spun around instantly, catching sight of several Lizardmen. Even though I’d been expecting them, I had still managed to be caught off guard. These were creatures that made wetlands and lakes their strongholds; I should have accounted for their ability to move through the water.
Fortunately, the veterans of Evil-Dispelling Sword hadn't shared my lapse in focus. Their leader, Ressel, cut down every Lizardman before they could even lunge, causing them to dissipate into mana before we even had a chance to move. They were B-rank adventurers for a reason.
But the ambush didn't end there. More Lizardmen surged from the water in rapid succession. And it wasn't just common grunts—high-rank species like Soldiers and Shamans were mixed into their ranks. To make matters worse, monsters had now blocked our path forward as well as our retreat. We would have to annihilate them all if we wanted to move an inch.
"We'll handle the ones behind! You lot take the front!" Ressel barked.
With that, our roles were set: we were responsible for the forward path while Evil-Dispelling Sword held the rear.
Dealing with the Lizardmen in the tunnel ahead was relatively simple. The passage wasn't particularly wide, and as Zephyr skillfully swung his greatsword, any Lizardman within his reach was instantly erased. The Soldiers could withstand a single blow, but even they couldn't do much against him. They were helpless against the relentless, sweeping strikes of his massive blade.
While Zephyr held the main path, the ones leaping directly out of the water proved more troublesome. They were cunning, specifically targeting Halfa and Eina, since both were ill-suited for close-quarters combat. Protecting them fell to Lowell and me.
Lowell’s lightning-imbued strikes were devastating, slaughtering even the Soldiers in a single flash. As for me, the Soldiers were a bit of a challenge. My style focuses on surprise attacks and ambushes, making me less effective in a straight defensive line.
Acknowledging that, I left the direct interceptions to Lowell and focused on the Shamans firing magic from the opposite bank. By timing my strikes with Rune Breaker, I was able to nullify their projectile spells as they flew toward us. While I kept their magic at bay, Eina and Halfa picked the Shamans off. Their constant bombardment was a nuisance, so we needed to thin their numbers fast.
We held the advantage, but the Lizardmen kept coming in a seemingly endless tide. Even Evil-Dispelling Sword seemed to be stuck in a war of attrition.
It was Shiroru who finally broke the deadlock. I’d noticed she had been quiet for a while, but it turned out she had been charging up for a big move. Shiroru, who had been crouching low while crackling with electricity, suddenly stood tall and let out a sharp "Waf!"
In that instant, a massive bolt of lightning erupted from her horn. It struck the water, and given the high output, the electricity propagated through the sewage across a massive area. The Lizardmen lurking beneath the surface all floated to the top before dissolving away. It was a total sweep.
"Amazing, Shiroru!"
"Waf!"
When I praised her, she wagged her tail happily. Since the members of Evil-Dispelling Sword were watching, she refrained from sending any mental messages. However, since we’d likely need to use Thought Transmission in an emergency, it was probably better to be upfront about her. I decided I’d explain everything once things settled down.
"Right, looks like the reinforcements have stopped!"
"Yeah. Let’s clean up the rest."
Whether they had been wiped out or simply retreated, no new Lizardmen appeared after Shiroru's lightning strike. From there, it was only a matter of time before the battle concluded.
"Phew, good work. You guys are better than I thought."
As I finished off the last Shaman, Ressel called out to me. He seemed to know Lowell, Zephyr, and Eina, but this was the first time I’d really spoken to him.
"I am C-rank, after all," I replied.
"So it seems. That tamed monster of yours was something else, too. Honestly, she saved us a lot of trouble."
Even a B-ranker like Ressel recognized the value of Shiroru's power. I figured now was as good a time as any to introduce her properly.
"This is Shiroru. Try not to be too shocked, but... she’s a Holy Beast."
"...Huh? Wait, what? A Holy Beast?"
‘What’s wrong? Is it okay if I talk now? I’m Shiroru the Holy Beast! Nice to meet you!’
"Gah!?"
Ressel and the rest of Evil-Dispelling Sword were floored, but they accepted the truth surprisingly quickly. It probably helped that Mildas had already introduced Halfa as the Maiden of the Destiny God. In their minds, if there was a Maiden, it wasn't a stretch for a Holy Beast—a Kin of the Destiny God—to be accompanying her.
As we continued toward the deep floors, we filled them in on the finer details of the situation. We had charged into the sewers with only a brief explanation because time was of the essence, so we used this walk to explain the Evil Cult’s schemes, the risk of the dungeon collapsing, and the item we carried to stop it.
Suddenly, Halfa called out.
"There! It’s just ahead!"
We had reached the entrance to the deep parts of the dungeon. A massive hole had been bored into the side of the waterway wall, leading to a set of stairs that descended even further into the earth.
The cultists had to be waiting somewhere down there.
We had to stop them... no matter what!