The next morning.
I was on a small boat crossing the lake under the cover of the pre-dawn darkness. Accompanying me were the members of Shikumu's Pier, who had volunteered to help with the guide work and manual labor for the hot spring cleaning job I’d accepted from the Lord.
"I didn't realize you knew how to handle a boat, Kai-san."
"Anyone living in our village can do this much. Right, guys?"
"Boats are the most common way to get around in these parts, after all."
"Whether you’re heading to the big city for supplies or transporting a patient to the next village, a boat is always the fastest and most convenient option. Even if you aren't a fisherman, the adults teach you how to handle an oar when you're just a kid."
"I see."
Transportation methods really did vary depending on the region.
"Ryoma, look at that."
I followed Sein-san's gaze, wondering what he’d spotted.
"Ah, those are... 'Nest Rats,' if I remember correctly?"
On my first day here, Kei-san had shown me around the village and pointed out these monsters that lived in the lake. They looked like adorable sea otters or beavers. A group of seven—no, eight of them—had gathered and were pushing a nest that resembled a raft made of woven logs and branches.
"Once those little guys start moving their nests like that, it's a sign that the Mad Salamander hoards will stop coming soon. It’s the signal that the fishing season is almost over."
"Oh, is that how it works?"
"They apparently have a sense for when the 'wave' of Mad Salamanders swimming upstream is ending. Once the wave subsides, they anchor those nests near the mouth of the river flowing out of the lake and settle in for the winter."
"If they tried to anchor them while the wave was still strong, they'd just get crushed by the swarms. They wait for a sweet spot where the numbers have thinned out enough that the Salamanders won't break their homes, and then they lock them down," Peiron-san and Shin-san added, deepening my understanding.
The locals likely judged the timing of their fishing season by observing the ecological shifts of the resident monsters.
The Mad Salamander wave was almost over. In other words, the subjugation mission was in its final stretch.
And at the same time, it meant my life here was coming to a close.
...I needed to make sure I lived each day fully so that I’d have no regrets.
We spent another thirty minutes chatting as we crossed the water.
Finally, we arrived at the port of the larger city.
The shoreline facilities weren't much different from those back in Shikumu Village, but the sheer number of piers and the scale of the processing plants were on another level. There were likely many people here from other villages to do their shopping as well. Despite the early hour, boats were constantly moving in and out. The area buzzed with life, and I could see large buildings towering over the city streets beyond the beach.
"Over here!"
A man stood on the pier, calling out to the incoming boats and waving a hand-sized flag. From the look of things, he was directing traffic. Kai-san followed his signals and brought the boat alongside a vacant pier.
"Alright, we're clear to disembark."
"Thank you very much."
"Oof, it's freezing out here."
"The air on the water really gets to you this early in the morning."
"Want to grab some soup at a stand?"
It was already the kind of morning that felt like the dead of winter, and after the cold boat trip, no one objected to Peiron-san’s suggestion to warm up.
Many others seemed to have the same idea. On the main street just past the beach, rows of stalls were selling hot soup and stews. I counted at least sixty just at a glance... with so many options, it would usually be hard to choose, but the members of Shikumu's Pier walked ahead without a moment’s hesitation.
"Do you already have a place in mind?"
"Hmm? Oh, right. You wouldn't know, Ryoma-kun. My older brother actually runs a stand here. It's basically a rule that we eat here whenever we come to the city."
"I see."
We arrived at the stall as we spoke.
Since they were all family or friends, the greetings and orders were finished in a flash, and the conversation immediately turned to catching up. I was introduced to the brother and served a bowl of hot stew. Although the seasoning and ingredients were tailored for a street stall, the flavor reminded me of the home-cooked meals I’d had at Kei-san’s house.
Once we were sufficiently warmed, we headed straight for the Lord's mansion.
We arrived in about twenty minutes after catching a shared carriage.
The Lord's mansion sat at the very end of the main street that led up from the beach. It was a grand estate. A perfectly normal grand estate... that might sound like a strange description, but it certainly wasn't a fortress like the Ducal House.
To put it kindly, the design was simple and sturdy, but it lacked any real ornamentation.
Though constructed of brick and mud, it gave off the strange impression of a massive apartment complex.
The building was surrounded by a fence, with Pig-kin guards stationed at the gate.
When I explained our business, they were very professional.
"We were expecting you. I will call the official in charge immediately. Please wait a moment."
A man who appeared to be that official stepped out shortly after.
"Thank you for waiting. You must be Ryoma Takebayashi-sama, and the members of Shikumu's Pier. My name is Pigu. I look forward to working with you today."
"Likewise."
He looked to be in his fifties or sixties—perhaps even older.
He was a Pig-kin with a fleshy build, and his sagging cheeks gave him the air of a gentle, kindly grandfather.
He had prepared a carriage owned by the Count's household to take us to the mountain where the hot spring was located, so we boarded and set off immediately.
We reached our destination in under an hour, but the real challenge started there.
"Whoa!"
"Sein!"
"I'm fine! My foot just slipped!"
"Man, be careful."
"The slope is steep. If you take a tumble, you're going all the way down."
"I am terribly sorry... There used to be... paths that were much easier to walk... in the past..."
"...Shin, everyone. I suggest we take a break."
"Good idea. Let's do that."
The climb from the foot of the mountain to the spring had started with some maintained stairs, but it quickly turned into a three-hour trek up a steep mountain trail. When we finally reached the site, I had to double-check.
"Is this the spring from the request?"
"It’s... a little different from what I imagined," Kei-san muttered.
As he said, the smell of sulfur and the sound of rushing water were present, and I could see steam rising into the air. However, the only structure was a single, grime-covered hut that looked like a shed.
"Yes, this is it. Phew... The previous Lord who built this place disliked vanity. He insisted that a small cabin like this was all he needed..."
"Let's take a look inside. Pigu-san, please take a rest while we check it out."
"I appreciate that. Here is the key. The interior is quite cramped, so I will wait out here. Please call if you need anything."
The climb had clearly taken its toll on the elderly man. He sat down to rest on what looked like a clump of grass—though on closer inspection, it was an old bench completely swallowed by vines—beside the entrance.
I used the key and stepped into the cabin.
"..."
The interior was indeed tiny. With five adults and one child from Shikumu's Pier, we were practically shoulder-to-shoulder just standing there. I didn't know the physical dimensions of the previous Lord, but if he was anything like the current, sumo-sized Count, this space must have been the absolute bare minimum for one person.
The furnishings were sparse: a basket for clothes in the changing area and a chair for resting. Aside from a hand-drawn map hanging on the wall, there was nothing else. The room wasn't actually that dirty—mostly just dust and cobwebs.
"Cleaning this part won't be an issue. The real problem must be through here."
I opened the door at the back of the room, revealing a short flight of stairs.
Three steps down, the space opened up into a spacious outdoor bath.
However...
"Whoa..."
"This is nasty..."
"I couldn't call this clean even if I was trying to be polite."
Shin-san and Peiron-san were right.
The bath had been built by carving out a tub and drawing water directly from the source.
From a quick glance, the design allowed the spring water to flow constantly into the tub, overflow onto the floor, and then drain out through a trench carved into the stone.
The problem was that the drainage trench was currently packed with fallen leaves and branches that had blown in. Because the water couldn't drain, it had become stagnant, and a foul stench—distinct from the sulfurous scent of the spring—wafted from the pool.
But that wasn't all.
"Calcium carbonate crystals... and is that iron content too?"
Mineral deposits had encrusted the bathtub and formed a thick layer across the entire floor where the water had overflowed. Brownish lumps were stuck to the mirror in the washing area, and the walls were dotted with handprints of the same color. These stains were solidified minerals from the spring itself; they wouldn't come off with a simple scrub.
"For now, let's start with what we can. 'Dimension Home.'"
I summoned my Scavenger Slimes and had them begin drinking the water, leaves, and branches to clear out the debris.
"Focus on that clogged drainage trench. I want it spotless."
The slimes pulsed in understanding. Leaving them to it, I stepped back outside.
Pigu-san looked up at me with an anxious expression.
"Oh? Is something wrong?"
"I'm draining the water from the bath. I'll be making preparations for the next stage while that finishes."
"I see... Do you really think... it can be cleaned?"
"The things you're worried about are those solidified deposits on the walls and floors, right?"
"Precisely. I have tried many times myself, but no matter how hard I scrubbed, those lumps wouldn't budge."
Just as I suspected.
Components in hot spring water precipitate due to changes in temperature or pressure, settling as solids. These mineral deposits are often seen as part of the charm or character of a hot spring.
On the other hand, they also stick to tubs and floors or clog up pipes, making them a major headache even for hot springs back in Japan.
Pigu-san made a frustrated scrubbing motion, but if the deposits were this thick, manual labor alone wouldn't cut it.
"I’m going to make a solution to remove them right now. It'll be a bit of a makeshift job, though."
"What! You can make such a thing?"
"It's an improvised fix, so I just hope it works."
First, I used Earth Magic to create some ceramic jars to hold the chemicals.
Then, I summoned my Sticky Slimes and Acid Slimes from the Dimension Home and had them produce their adhesive fluid and acid.
"The deposits in that bath are made of calcium carbonate. It’s similar to sea shells, which makes it weak to acid. I think I can dissolve it using the Acid Slimes' secretions."
"Is that true?"
"Most likely."
If I just poured pure acid on the deposits, they would dissolve, but the acid would be so strong it might damage the underlying stone of the floor and walls. To prevent that, I used the Sticky Slimes' adhesive fluid to dilute the acid while also testing if I could increase the viscosity to make it stick to surfaces.
...About this ratio, maybe?
"I'm going to run a little experiment."
I took the Acid and Sticky Slimes back into the bathroom. Thanks to the Scavenger Slimes, the water had already been drained. I decided to test my mixture on the edge of the bathtub.
I had the Acid Slimes form a small circle on the stone and poured my mixed solution into the center.
"Whoa!"
Cheers erupted from behind me.
Pigu-san and the men from Shikumu's Pier had followed me in. They let out a commotion as they watched the liquid begin to foam and fizz violently where the acid met the calcium carbonate crystals.
The acid was definitely working, but it still looked a bit too concentrated for general cleaning.
Also, while the viscosity was higher than the pure acid, it was still a bit too thin.
I needed to adjust the ratios.
After several rounds of testing and tweaking, I successfully created three types of Acidic Cleaning Fluid: a "high-acid, low-viscosity" version for thick mineral layers; a "low-acid, high-viscosity" version for walls and thin deposits where the liquid needed to stay in place; and a "balanced" version for general use.