And the next day.
　Me, Amu, Eifa, and Mabel were walking along the pathway of the sewer that stretches underneath Rhodonea.

　It's a sewer, but this place is the main stream and the channel is as wide as a large river. Furthermore, the ceiling was quite high, perhaps in preparation for when the waters rise.
　It was much wider than the underground dungeon where I wandered into last year.

　I looked around and muttered my thoughts.

The smell isn't as bad as I thought it would be.
Yeah, of course.

　Amu, the lead, replies.

'There's water dripping from the water supply all the time that isn't being used.

　Rodnea draws a large amount of water from two water sources in the vicinity.
　The water is not stored in a large pond, so the overflow from the water supply area goes straight to the sewage system.
　Since there seems to be quite a bit of water, the flow of the sewage is not that dirty.

Well, that doesn't mean I want to stay here for long, though.

　It's not just the location, but also the time. It's a long way to our target point, so if we faltered too much, it would be nighttime.

　In the end, our departure had been delayed until after lunch.
　It took me some time to find the entrance and somewhat more time to convince Saisha that I was going too.
　She seemed to have a good record in practical magic skills, but without her experience in roughing it, she would only be a liability. It would be more helpful if you waited quietly.

　We walked down the pathway beside the canal, with Amu in the lead.
　Following Amu are me and Eifa, and Mabel in the back. And Mabel is the last one.
　Since the passage is not so wide, only one person can be left in the vanguard when considering the space to wield a weapon.
　It's not really a problem, though.

"Hey, Amu-chan.

　Yifa raises an anxious voice as she looks across the waterway.

''This, there won't be any monsters coming out of the river.......right?
Hmm, I don't know.
Yeah, yeah....

　Yifa moves away from the flow of sewage as if she is scared.

　Yifa's anxiety is understandable.
　Even though we have the vanguard in place, there is no formation or anything if we are unexpectedly side-swiped from the river.

　Amu laughs at Yifa's fear, and says with a giggle.

''It was a joke. The only monsters that live in the sewage are aquatic slimes at best, so it doesn't matter.
Oh, yeah...
Sometimes, though, scary things come up from the river that flows into it.
'Yes....'
Hey, you scared the shit out of me. It's okay, Yifa.

　I had thought about this possibility, too, so I took some measures.

　At that time, I heard a faint sound of wind noise coming from the ceiling of the passage.
　Amu is the first to swing overhead and look up, and behind him I can sense Mabel preparing herself as well.

　A large bat-shaped monster appeared in the light of the Hitogata that illuminated the overhead - a large bat-shaped monster.
　But before the two girls could take action, the hitogata was stuck to its nose.
　They made a mark with one hand.

《Phase of Yang----Jutsu of Thin Lightning (Huhari)

　With a bang, sparks flew and the bat fell into the waterway with a white smoke billowing out of it.
　It's much less powerful than the original lightning bolt, so maybe it's not dead, but........well, that's okay.

　Amu says as if he was half dumbfounded.

''Well you're reacting too quickly, aren't you?''
Really?

　It's a lot easier to have substance compared to the demons that dissolve in the dark night and attack you.

　In addition, I've been regularly shooting "lightning" into the waterway.
　Even if the monster was a little powerful, it wouldn't be an easy thing to deal with, so it shouldn't be able to catch me by surprise from within the water.

　After another short while, this time two rats (rats) as big as wolves appeared at the front of the passage.
　In the lamplight, they twitch for a moment, then peel their front teeth at us.

　The teeth, which reflect the light, are dull in color.
　I'm pretty sure it's a ferric rat or some other rat-shaped monster with iron teeth.

''It's finally out.''

　Amu holds his sword while laughing.
　Two Hitogatas fly from behind them and stick to the head of the Ferrick Rat.

　Sparks fly with another bursting sound, and the two monsters turn over and start to convulse.
　The smell of burning body hair is in the air.

　Amu looked back at me and said in frustration.

''Hey, these things are usually handled by the vanguard,''
It's a win-win situation.

　I just want to get it over with and get out of here.

Hmph.

　Amu walked up to the Ferrick Rat carcasses in frustration and kicked them both into the sewer.

'Hey, aren't you going to retrieve the material?　As I recall, metal teeth sell for a reasonable price.
'It's okay, it's not a lot of money. You just want to go home early anyway.
....

　When Amu said as if he was sulking, I couldn't say anything.
　Oh my........did I put you in a bad mood?

　Thinking this, I let the Hitogata fly to the wind noise I heard above me again.
　But before the Hitogata could stick, the thrown sword that flew in from behind had pierced the bat-shaped monster that was attacking it forcefully.
　The thrown sword flew through the monster and flew away, dropping in a parabolic pattern into the water in the distance.

　I turned around and said, a little dumbfounded, "Mabel.

"Mabel," I said, a little dumbfounded, "we can't retrieve the projectile here. You can't retrieve the thrown sword here, so why don't you just let me handle the enemies from a distance?
Good. I'll do the same.

　Mabel said with a motivated look in her eyes.

　Hmm, what's going on with this girl all of a sudden?


****


Oh.

　After another few moments, Amu suddenly shouted and rushed over to the wall of the passage.
　He crouched down as if he had found something.

'What's up?'
Found.

　The one that he pinched with his finger to show me was an imperial silver coin.

　It's unlikely that someone dropped it here........so it was probably caught by something that overflowed from the canal when the water rose due to rain and other factors.

'Huh. So it's true that money and goods have fallen into the sewers.
Hmmm....

　With a simmering reply, Amu walks off again.

'It's still weird.'
What?
It's a little too clean for a sewer.
Oh, is this thing beautiful?

　Yifa says, looking at the wall where something soggy and sticky is stuck.

'No, it's not that. It's just that it's kind of too tidy.

　Amu continues as he walks.

'Sewer corridors are usually a lot more cluttered. Trash, metal shavings, and so on. But there's hardly any of that here. I'm sure no adventurers have been diving here for a while.
Hmmm...
And...

　As he said it, Amu pointed his staff sword forward and unleashed an unprovoked water magic technique.
　Several icicles stabbed at the ferric rats in front of him, killing them in an instant.

''Other than the bats, it's all iron rats and no slime at all. I guess that's why there's so much sludge-like buildup.
Do slime eat sludge?
Come on. But doesn't it feel like that?

　Well, I can see that.
　I think for a minute and open my mouth.

I don't know what a ferric rat is, but they eat everything. Everything from scrap metal to monsters. What do you think it means when it's that rat that's eating all the trash and slime?
Hmm. It's a bit small for a mass outbreak...

　Amu says crisply.

'Maybe there's a lot of them stuck somewhere...'

　And then Amu stopped abruptly.
　I also felt an inexplicable presence and strengthened the light of the Hitogata.

　The faint light illuminated the black fur of the ferric rats.
　It wasn't just one or two rats. A swirling line of black fur filled the far end of the passage.
　It was truly a horde.

　Countless eyes, illuminated by the light, turned to us.
　Maybe it's because they're all here in numbers, but they don't show the timidity they had when they were alone.

"....

　Amu, whose expression was tightened, backed away.
　Well, this is indeed the work of the rear guard.

　A swarm of rats approaches us with a few brave ones in the lead.
　And when I was about to release my magic, a tremendous gust of wind suddenly blew from behind me.

　The wind whisked away the swarm of rats and blew through to the end of the passage.
　The ferric rats that were blown off fell one by one into the waterway. The lightning bolts that had just been sent by "lightning" electrocuted the rats, and they were swept downstream while floating on their feet.
　The few that were lucky enough to stay in the passage were either unconscious or dead, and showed no signs of moving.

"...Was that Yifa?
'What?　That's right.

　Yifa replies as if it's nothing to worry about.

''Oh, you ... were you able to produce this much magic power?
''Ehehe, there were a lot of spirits in Astiria where I went on summer vacation. Also, I have some that Lize-san gave me.
....

　We are silent, but Yifa nods her head and says, "What's wrong?

What's the matter?　Can we move on quickly?