''This, this........what is this!''

　Lithou-san sees this and shouts in surprise.

　We got rid of Bahamut, which dwelt at the lowest level, and headed back to the original path and headed downstream this time.
　The reason for this is because there is a high possibility that this path, which was created beside an underground water vein, continues to the outside.
　If such a loophole exists, there is a high possibility that many demons and chimeras have been unleashed on the outside world.

　That's why we kept going downstream to defeat the demons and chimeras we encountered.
　And this is what we found: a dead end.
　But when I say dead end, I mean it's just a dead end for the path we've taken.
　The water in the underground water vein itself continued deeper through the hole in the wall.

　And what surprised Lisou-san was the hole in the groundwater vein.
　Strictly speaking, though, it was against the destruction that seemed to have forced the hole through which the underground water vein flowed to be crushed and widened.

'Looks like something forced the narrow underground water vein channel to widen and go deeper.

　Mr. Ramise looked at the expanded hole and guessed what had happened.

'You mean they proceeded to crush the rock?　Is a chimera capable of such a thing!

　Mr. Lissou asks Mr. Gan-ei, the creator of the chimera.

"Hmm, is there any chimera with that much guts in that demon's failed chimera creation?

　And while remembering the chimera created by the demon, Ganei-san tilted his head and thought about it.

''Ah.....


　Then, as if he remembered something, he raised his voice.

''Come to think of it, we didn't see any prototype chimera before we got here.

""Prototype Chimera?"

This is the final prototype chimera that I made to embed the pieces of the white disaster in. Since it was the last one I made, I'm quite proud of it, or rather, it was a masterpiece. But I didn't want to waste the last remaining pieces of white disaster, so I ended up just testing the performance of the body and then dropped the rest into a hole and disposed of it.

Why did you send such a dangerous thing down the drain?

　Everyone's tsking echoed through the lowest levels.

'No, it was so good, I couldn't bear to kill it with my own hands.

'No, no, that's not right. I mean, it's not normal to abandon such a dangerous chimera!

　Roddy shouted out, and Lisou and the other S-rankers who had fought chimeras with him nodded in agreement.

''Hey Roddy-sama, was the chimera that Roddy-sama and the others fought against that strong?''

　'What do you mean?' asks Mr. Almo, Roddy's fellow monk.

'Hmm?　Yeah, it was pretty strong. But I hear the one we fought was a failure until we made the real deal, though.　

A failure?

　Remembering the battles with chimeras he encountered in the courtyard and in the lab, Roddy-san nodded with a face that looked like he'd bitten down on a bitter worm.

''Yeah, especially the fight with the giant chimera we encountered in that courtyard, I really thought I was going to die.

'I can't believe Roddy would say that...'

　Mr. Chain, another wizard friend of Roddy's, joins the conversation with great interest.
　Since he is a wizard, he seems to be interested in chimeras created by magical technology.

I'm sure you'll find a lot of people who are interested in the chimera that were created by the magician's technology. If we Cyclones had been commissioned alone, we might have been wiped out before we encountered the completed chimera.

''........Oh no, that's it!

　' said the swordsman Marcha, the last one in Roddy-san's party, surprised.
　Because they trust Roddy-san wholeheartedly, that statement seems to have come as a shock to them.

''Honestly, it was only because of the boy's presence that we were able to survive.

　Roddy looks at me and says.

'That girl again...'

　Armo-san is staring at me.
　His eyes are filled with mixed emotions, as if he's angry or not.
　You must be wondering if you really owe it to me to save your life.

"No, no, that was just a kind of welcome to me as a rookie S-rank, if Roddy-san and the others had really fought, I wouldn't have had a chance.

""Of course!"

　Roddy's party members smile at my words.
　Everyone really trusts Roddy-san, don't they?

''No, it's true that I struggled, but...''

　But Roddy-san takes the stance that it was only me who defeated the chimera.
　I was only pretending that I was struggling on purpose to prepare for the test, and if I had fought seriously, I could have won the test without any trouble, but he doesn't say that because I was able to defeat the chimera and the demon on my own.

　But I'd like to see Roddy and his team do well one day.
　This is the seriousness of an S-ranked adventurer who excels at teamwork, so I'm sure it will be great.

''But it's impossible to track them with this...''

　Oops, Lisou and the others kept talking about it.

''Mm, because if you jump in here, you'll definitely die.

　Huh?　Dead?　Why?　I mean, why jump in?
　I think this would just be a normal way to expand the hole.
　Let's give it a try.

"Tunnel Extension!

　I activate my magic and widen the hole forced by the chimera, while reinforcing the ceiling and walls to further change the rate of expansion of the hole to create a path beside the underground water vein that is only walkable.

'What's it possible to do?'

　I was surprised when Lisou-san and the others said we couldn't track them, but I was still able to widen the hole normally.

''Then let's track the escaped chimera, shall we?

"..........

　And when I turned around, for some reason, everyone rolled their eyes and looked at me.

'What's wrong with you all?'

　That's not it!

　For some reason, everyone came rushing in, their voices humming.
　Huh?　What do you mean?

Whoa, whoa!　Why do you keep spreading your holes out like a commonplace?　What kind of magic is that?　Naturally, tell me!

　Magic-loving Ms. Rameez comes up to me with excited eyes, but Foca and Roddy appear behind me, catching my arms and dragging me away.
　Then Lisou-san comes forward instead.

'Big bite, was that ... magic ...?'

Yes, it's a mining spell to expand the cave.

"Mining magic?　But don't you think a bunch of amateurs who aren't miners are gonna blow a hole in a cave and it's gonna collapse?

　Oh, Lissou and the others don't know about the miners' magical skills.
　That's why I didn't think they could widen the hole and track it.

''It's okay. With mining magic, expanding the cave won't cause it to collapse. Rather, the soil and rock that you expand will increase the density of the surrounding hole, so if you only expand the hole a little, it will only become harder.

Well, that's what magic can do.

It's the same reasoning behind the hardening of soil and snow when you push it into the ground. It's often used in mines with geological features that are prone to collapsing.

Is that so?

What?

　Adventurers, do you know who you are?　And check with each other.
　It may be a magic that you don't get a chance to know unless you know someone in the mining industry.
　I was told by a smith I know that I should look for good materials with my own eyes, and he taught me how to do it.
　I spent a few months in the mine until I was able to appraise a good ore.
　Yeah, let's forget about that time.

Well then, let's go!

'Oh, yeah...'

But first, you need to tell me more about your magic.

Okay, okay, you're a good girl, so let's talk about that kind of stuff after work.

No, I'm in ministry.

　Well, I'm supposed to teach you later.

I can ask a wizard who works in a big mine and he can teach me.

Okay, I get it!　You're the mine's resident wizard!

　I knew that Rameez was going to be cool.

　But still, it's a prototype of the most powerful chimera that was created to defeat a mysterious demon that brought down an ancient civilization.
　This is going to be a pretty tricky opponent waiting for you.

　◆

　As you use your mining magic to expand the hole as you go along, the wall ahead of you collapses with a bobbing sound, revealing a pitch black hole.

'It looks like it led to a passage somewhere.

Hmm, we may have a Chimera on the loose ahead of us. Everybody stay alert!

　Everyone readied their weapons and got ready for battle as Mr. Lissou ordered the alert.

''Then let's proceed.

Wait a minute.

　But I stop everyone from moving forward.

"What's up with the big bite?

'We will magically investigate the space connected before that. Air-diagnosis!

　A magical ball of blue light was released from the tip of his hand and proceeded to the hole in front of him.
　Then the blue light turned to purple in the middle of the day, and the next moment it transformed into a bright red color.
　Ah, I knew it.

It's changing color!

"Big bite, what does that mean?

　Mr. Risow asks me, and I tell him what the red light means.

'That indicates that the air ahead is filled with poison.

'Poison?

　Everyone in the room shouted in surprise and backed away.

What do you mean, big bastard?

The mines are sometimes filled with poisonous air that is toxic to the human body. This magic is used to test those poisonous air. Blue is clean, purple is dangerous to stay in for long periods of time, and red is deadly.

''How dare you!?''

　Lisou-san's face contorts in frustration.

''We can't go on like this........''

So let's just magically cleanse the air ahead of us and move on.

...What?

　What's Mr. Lissou talking about?　He looks at me with a scowl.

'I'll use mine magic to purify the air of poison down the road.

This is what mining magic can do?

Yes, it's a magic that was developed to work safely in the mines.

"Some serious mining magic.

Are those miners a badass bunch of guys?

　The adventurers are having a conversation to change their perception of miners.

''Yes, miners are often fighting ancient and powerful demons that have been lying dormant in the mines, so miners have an aspect of being strong warriors as well.

"Seriously?　That's some miner!

I'm sorry I thought you were a rock digger!

"Hey, man, did I get robbed by that old miner the other day?　What am I going to do?

Go apologize now!

Oh, I'm off!

Wait until you're done with your work, you idiots!

　Oh, Lisow scolded me.

'Anyway, if you can purify the air, can you ask for it, big eater?

Yes, I'll take care of it.

　Lisou-san asks me to invoke the air purification spell.

"Air Purification!

　When I release my magic into the space ahead again, the ball of air-diagnosis, which had been dyed bright red earlier, returns to blue.

''The purification is complete. Let's go then.''

'Oh, yeah. ...You're sure you're okay with this?

Yeah, I'm fine.

　We resumed our movement and proceeded along the underground water vein, keeping the ball of air-diagnosis ahead of us.
　On the way, the light of the ball turns red again, so we purify the air each time.

'Hey, the color is turning red every time, are you sure you're okay?

Roddy asks me a question anxiously, and I say it's okay to reassure him.

'Air Purification is a magic that purifies the air several hundred meters around the surgeon. So if this entire corridor is filled with poisonous air, just purify the air in place every time you move and you'll be fine.

Oh, so that's what it is.

　As I went on, I heard something approaching from deep in the cave.

'Something's coming!　Get the lights ahead of me!

　The wizards were instructed to move the magic light forward.
　Then the figure of a demon that came from the back came into view.

''That's a Hellbasilisk!''

　The adventurers are upset when they hear the name.
The name is the name of the demon that attacked the camp in front of the mine before we arrived and endangered the lives of many adventurers with its special evil eye called the Black Death's Evil Eye.

''Recoverers, fall back to the rear!　Strike from a distance to avoid the Black Death's evil eye!　Shield bearers, step forward!

　Immediately, the adventurer with the shield steps forward while holding the shield to avoid receiving the evil eye of the Hell Basilisk.

''Wind Lancer!''

　In order to prevent the cave from collapsing, Ramise intercepted the Hellebasilisk with wind magic.
　Okay, I'll intercept!

"Land Lancer!

　I also attack with my rock spear magic to match Ramise's.
　I'm not going to be the only one who's been in the market for a while.
　It is a very good idea to have a good idea of what to expect when you are in a position to do something.

''Oh, hey, I've already taken him down!

'What?　What?　Is it over now?

　Hearing the voice of the adventurer who was waiting behind him, the adventurer who was holding his shield at the ready let out a cry of surprise.
　Well, it was only one Hell Basilisk that attacked us, you know.

''Because the Hell Basilisk has a soft stomach like other lizard-type demons.

Oh, I didn't know you had such a weakness.

No, no, no, no, even if you know the weaknesses, you can't take them down easily.

More importantly, my magic wasn't noticeable at all...

　Rameez-san who used wind magic is a shawnee.

''But thanks to Rameez-san's magic stopping the progress of the Hell Basilisk, my magic hit just the right spot.

Hm?　Really?　Well, yeah.

　Rameez-san, who had cured his mood by being praised, grinned.

''Isn't that a bit cholo, Heavenly Demon Master?''

　Although Roddy-san is staring at Rameez-san with a dumbfounded face, Rameez-san's magic actually made it easier for me to apply my magic, so it was certainly more effective.
　Wind magic is invisible, so it's useful for surprise attacks and planting, but it's hard to tell how well it works.

''But to think there are demons in a place filled with poisonous air like this...''

"It is said that the Hellebasilisk prefers unholy places. Perhaps these caves, filled with poisonous air, are a good place to live.

　Rameez's guess was correct, and the poisonous demons and chimeras continued to attack us after this.

''I see, the poisonous demons and chimeras seem to have fled to this area to escape from Bahamut and other high-ranking demons!

　While dealing with the poisonous demon, I guessed the reason why Lisou-san was even in the chimera.

''Then maybe there's a path leading here somewhere in the cave. I'll have to instruct him to be careful with the poison when I send a survey team later!

　Mr. Roddy also insists that we should warn people about the poisonous air for later on.
　Both of them are even thinking about what happens later on.

''Oh dear, with so many poisonous demons, the antidote magic won't be able to keep up with them. It was a good idea to bring more mana potions.

　Foka-san, a monk, is using antidote magic to recover the poison that the injured people received.

''Cease ministry.

　Liliella wields a sword that has the attribute of ice with attribute strengthening magic and freezes the claws and bills of demons to prevent them from being poisoned.
　And when the demon attacks that evade and counterattack, she creates ice armor on parts of her body to prevent the poison from invading her body.

''Taa!''

　And then, as it was, she attached the ice armor to the demon's body, making it unable to attack in reverse, and then attacked again.

　Liliera-san is becoming quite proficient at using the attribute enhancement.
　Maybe I should teach her a new technique next time.

''Mocu!''

　And Fluffy Fluff was devouring the meat without regard to whether the other party was poisonous or not.
　Don't spoil your stomach!
　.........Huh?　I thought I left Fluffy behind, and now you're following me?
　Oh dear, it's no use.

Hey, hey... that white bastard is eating a poisonous monster!　Is she okay?

I mean, she's an S-rated pet, don't you think?

''Well, it's an S-ranked pet........''

　No, it's my pet, so it's not like it's okay.

And so, as I fight my way forward, I hear a buzzing sound from the depths of the cave.

''What's that sound...?''

''Ah, it looks like this area is the source of the poisonous air. Look, see those blinking balls of air-diagnosis?　That one is telling us where the poisonous air is particularly dense, or the source. Even if you purify the air here normally, it will soon be filled with poisonous air.

　Everyone's faces turn blue after my explanation.

'So you mean we can't go on now?'

''Oh no, after coming all the way here after defeating the Hell Basilisk and poisonous demons, we have to give up!

　The adventurers shouted in frustration, wondering if they could give up after coming all the way here.
　Yes, as expected of all of them, they're all brave.
　He showed no sign of being frightened by the poisonous air.

''No, it's just a matter of plugging the hole, it's easy. Tunnel Extension!''

　I apply the magic of the cave extension to the entire space and expand the hole.
　Then the buzzing sound that had been heard throughout the entire cave just a moment ago quickly faded and finally disappeared.

''Air Purification!''

　And when he activated the air-purifying magic, the magic ball that had been flashing red earlier changed to blue, and it didn't change color as it was.

''I've filled the hole that was leaking poisonous air when I used my magic to expand the hole. Now you won't have to worry about the poisonous air overflowing anymore. All that's left is to purify the remaining poisonous air.

　After my explanation, everyone let out a sigh of relief.

''That's awesome mine magic. You can nullify the poison so easily?

'Yeah, yeah, it's great!　I can't believe you're purging an entire space of evil poison!　You should have come to the Holy City after all!

　I'm sorry, please don't get in the middle of the hustle and bustle and recruit me, Foca.
　Also, the poison in the cave isn't really evil.
　It's just that the people in the church have a strong impression that a poison that can be cured with sacred recovery magic is an evil force.

"Whoa!　I guess we can ask the miners about this too!　Wonderful mining magic!　No, you were right to take this commission!　New magical knowledge is coming your way!

　While everyone else was relieved, Ramise was the only one who was happy and excited.
　Then, after expanding the cave while purifying the air, we arrived at a large open space.

'Looks like this is the end of the line.

　The place we arrived at was a huge subterranean lake standing in the middle of a vast underground space.