A red magic circle.
The teleportation magic circle that had always glowed pale blue until now was red.
Red was the color that signaled danger.
There was even a term like "red zone."
This led somewhere dangerous.
"Something's ahead."
It was
It was probably an instinctive remark.
Whether
The guardian.
And yet, somehow, I was certain.
That beyond this magic circle lay the labyrinth's deepest level.
"What do you think, Paul? We've still got plenty left in the tank, but heading back for now is always an option."
The sixth floor had been easy.
Thanks to Talhand's roots, the Eat Devil had been nothing more than fodder.
Without needing to use anything special, we'd barely expended any energy—hardly an exaggeration.
We'd also gotten plenty of rest in the previous room.
"...No. Let's push on. We should check our equipment first."
"Understood."
At Paul's decision, everyone sat down and removed their equipment.
They began inspecting it more carefully than usual.
"Come on, Rudi, you too."
I took my belongings out of my bag, laid them out on the ground, and checked the count.
My belongings were sparse.
At most, I only had a few spirit scrolls.
"Rudi, would you like me to hold onto some of my scrolls for you?"
Roxy kept a few scrolls hidden away for emergencies.
They were scrolls of advanced magic.
She could cast multiple spells at a fairly high rotation rate through incantation reduction.
That said, advanced magic still required somewhat lengthy incantations.
So there were inevitably times when she couldn't get them off in time.
These were her trump cards for those moments.
"Sure, then give me a few healing magic scrolls."
"Okay."
Since I could handle incantation-less casting, I didn't need advanced magic scrolls.
But healing magic was different.
I'd take those just in case of the worst-case scenario.
Just in case—say, someone's throat or lungs got crushed.
I accepted the intermediate healing scrolls from Roxy, folded them, and tucked them into my robe pocket.
If I didn't use them, I'd return them.
I'd bring one back and have
Actually, wasn't unauthorized duplication prohibited or something?
I didn't think they'd catch you if it was just for personal use, though.
"I'm not sure what kind of guardian we'll be facing, but we have more than enough combat strength here.
I'll do everything I can to support you, Rudi, so you won't have to use those scrolls."
"Thanks. I'm kind of a coward at heart, so please help me out when it counts."
"You can count on me to watch your back."
Roxy said that and thumped her small chest with a fist.
She was reliable.
"
That was when Elinariése threw something over to us.
I caught what came flying—a round stone, like a marble.
It was one of the mana crystals Elinariése had several of.
"Use these when you run out of mana."
"Are you sure?"
"I'm only lending them to you. If you don't use them, give them back later."
"Ah, sure, got it."
Running out of mana during a labyrinth dive was possible.
But normally, that was when you retreated.
That's why we'd completely wiped out the enemies in the space behind us.
Retreat, recover mana, then try again.
But apparently there were times when you couldn't flee from a fight against the guardian.
You'd get trapped in something like an arena and couldn't leave until you defeated it.
Apparently that was a possibility.
The red magic circle in front of us appeared to be bidirectional.
But it might actually be one-way.
Surely there wouldn't be random teleportation. At least not this time.
"All right, is everyone ready?"
At Paul's voice, I stood up.
Looking around, everyone's expressions were tight and focused.
I needed to get my head in the game too.
"Rudi."
"What is it?"
"I know this is a bad time to say something like this, but..."
Oh. This was a death flag.
"Then don't say it."
"O-Oh, okay..."
Paul's face fell.
My morale might have dipped a little.
Well, this wasn't the time to make people say important things before a decisive battle.
That kind of thing could wait until we got back.
"All right, let's move."
We looked at each other and stepped onto the magic circle at the same time.
---
The space on the other side of the magic circle was vast beyond description.
If I had to sum it up in one word: majestic.
A rectangular hall the size of a baseball stadium, shaped like a palace.
Thick pillars stood in the corners of the room.
The ceiling stretched so high you had to crane your neck to see it.
The floor was tiled, each one carved with intricate relief patterns.
"Whoa...!"
In the depths of that gray palace, there was a single monster.
An enormous monster.
I had never fought anything this large.
It was roughly twice the size of the Red Dragon.
Even from a distance, you could see its emerald-green scales glimmering.
A stocky torso.
From it grew multiple necks.
"A hydra... first time I've seen one," Geese muttered.
That's right. A hydra.
A massive dragon with nine heads.
"It's there...!"
But that wasn't what I—or Paul—were focused on.
Behind the hydra.
In the innermost depths of the room it was guarding.
There sat a single mana crystal.
An enormous green mana crystal.
The marble-sized mana crystals Elinariése carried were nothing compared to this.
A crystal roughly two meters tall, shaped like a gemstone.
I'd never seen a mana crystal this large before.
But that didn't matter.
Size didn't matter.
What mattered was what was inside the mana crystal.
Inside the mana crystal.
She was there.
Zenith.
Zenith was trapped inside the mana crystal.
"Zenith!"
Paul screamed.
At the same time, a question mark—*why?*—floated up inside me.
Why was she in that state?
Why was she inside a stone?
Before I could voice those questions, Paul had drawn his sword in both hands and was already charging forward.
The hydra slowly raised its head.
---
"You idiot! Don't rush in!"
Geese's shout rang out.
"...!"
Elinariése clicked her tongue and dashed after Paul.
Talhand followed close behind.
Paul was sprinting so fast that Elinariése couldn't catch up.
"I'll provide support!"
Roxy shouted.
I snapped back to my senses and pointed my staff at the hydra.
Taking out the enemy came first.
One-shot it.
I charged a stone cannonball—the same spell that had blown even a demon king away in a single hit.
"Frost Fang Strike!"
Roxy chanted an intermediate spell and struck first.
A mass of freezing air shot past Paul at tremendous speed and hit its mark.
Schiiiing!
Just before impact, a grating sound like glass being scratched echoed through the air.
"What?!"
Roxy's eyes went wide.
The hydra didn't have a single scratch on it.
Was it resistant to cold?
That thought flickered through my mind for an instant, but Paul was already about to reach the hydra.
"Stone Cannonball!"
I released the fully charged stone cannonball.
The honed projectile flew with a high-pitched whine.
It passed just over Paul, who was a few steps from the hydra.
It hit the hydra.
Schiiiing!
That awful sound again.
"Deflected?!"
It hadn't dodged.
It should have hit.
It should have been a direct hit.
But that sound just now.
That high-pitched ringing—what was it?
The hydra stood there calmly, as if nothing had happened.
Not a single wound.
"Rraaaaaaagh!"
Paul's fierce war cry reached us even from there.
The hydra whipped its remaining necks around like snakes to intercept Paul.
Paul dodged with minimal movement.
In the next instant, a hydra head soared through the air.
His right-hand sword had swung through in a single devastating slash.
Incredible blade speed.
Paul's figure blurred for a split second.
He'd moved at a speed that even Foresight Eye couldn't fully track.
In the next instant, blood sprayed from another of the hydra's heads.
Paul's left-hand sword had sliced through as well.
But the blade wasn't long enough to cleave it clean through.
Paul spun his body, using centrifugal force to swing his right-hand sword once more.
The hydra's dangling head fell to the ground.
"SHRAAAAAAA!"
The hydra had lost two heads in an instant.
But a hydra didn't stop at one neck.
The hydra circulated its remaining necks, surrounding Paul from every direction.
Paul tried to create distance with a backstep, but whether due to his stride length or the hydra's reach, he couldn't escape its range.
"Paul!"
That was when Elinariése caught up.
Shield raised, she thrust her sword forward.
An invisible shockwave rippled outward.
Schiiiing!
That sound again.
The hydra ignored the shockwave completely and continued pressing Paul.
"Rushing waters, turbid and fierce! Water Stream!"
As Roxy completed her incantation,
a mass of water materialized in front of Paul.
Paul let the current sweep him away, carrying him out of the hydra's range.
As Paul tumbled to the ground, Elinariése immediately moved in to cover him.
Meanwhile, Talhand stopped at a midpoint and began chanting a spell.
It was unconventional, but it formed a front line, mid line, and back line.
What about the battle strategy?
Paul's attacks were working.
But my stone cannonball had been deflected.
Roxy's magic too.
Should I try fire next? Or wind?
Either one could catch Paul and the others in the blast.
What to do?
"Earthfall!"
Talhand finished his incantation.
An earth spell.
A mass of rock materialized above the hydra's head and crashed down toward it.
Schiiiing!
That sound echoed again.
Just before striking the hydra, the rock crumbled into sand and vanished.
That sound. Whenever that sound rang out, magic simply dissipated.
"Magic doesn't work on that thing?!"
What should we do?
Should we keep going?
Or should we retreat for now?
What am I supposed to do?!
That was when Roxy, standing next to me, called out in a desperate voice.
"Rudi, look at that! It's healing!"
I looked. The two heads Paul had cut off.
One of the stumps was bulging outward, flesh rising to reform a neck.
The other was regenerating right behind it.
It was regenerating.
Just cutting off its heads wasn't enough to damage it.
"Let's retreat!"
Roxy's voice.
But it didn't reach Paul.
Letting out a fierce war cry, he was hammering his sword into the hydra with everything he had.
What worried me was Elinariése, who was supporting that reckless fighting style—she was in danger.
"Geese!"
Talhand called out.
Geese was already running.
He sprinted past Talhand, moving up right behind Paul, and hurled something at the hydra.
Pap-pa-pa-pa—a burst of something popping.
Then thick smoke rose billowing around the hydra.
A smoke bomb?
"————!"
Geese was shouting something as he grabbed Paul in a bear hug from behind.
But Geese couldn't hold Paul. He was about to be shaken off in an instant—when—
The next moment, Elinariése slammed her shield into Paul's face.
"——!"
Geese released his grip, said something, and Paul came running back toward us.
"Rudeus!"
At Elinariése's voice, I sprang into action.
I concentrated all my mana into my hand and created a thick fog between the hydra and Paul.
A blinding white mist, like steam.
A smokescreen.
But I could hear the hydra thudding closer.
That said, it wasn't particularly fast.
Paul and the others made it back to us.
"Rudi, we're retreating. Get to the magic circle first!"
"Right! Let's go!"
I jumped onto the magic circle ahead of the others.
---
Everyone made it out of the magic circle safely.
Roxy, Talhand, Geese.
Paul, breathing hard.
And lastly, Elinariése emerged—wounded.
Elinariése was dripping blood from her shoulder.
"Are you okay?"
"Just a graze."
A chunk of Elinariése's shoulder had been gouged out.
From what I'd seen, she hadn't taken a direct hit.
"I was scraped by its scales."
Apparently the hydra's outer skin was rough, like sharkskin.
But it was within the range of what basic healing magic could fix without a trace.
In my previous world, that would've needed dozens of stitches.
What a convenient world.
"Thank you."
Now then.
The real problem was what to do about the thing that had caused this injury.
Paul was sitting in front of the magic circle.
His eyes were glazed over too.
Killing intent radiated from every part of his body.
"Dad."
"...That was Zenith. No doubt about it."
Paul said it.
His eyes held nothing for Elinariése's wound.
Well, Elinariése was the shield bearer—it was basically her job to take hits.
But still...
"Could you calm down a little?"
"Yeah, sorry. I'm calm right now."
Paul's voice was low.
The phrase "the calm before the storm" came to mind.
He was restrained, but he wasn't calm.
I supposed that couldn't be helped.
It really was Zenith.
Even I could tell it was Zenith just from a glance at a distance.
Paul certainly wouldn't have mistaken her.
The one inside that mana crystal—Zenith.
Trapped inside a stone.
Why had things ended up like that?
Well, the reason didn't matter.
Maybe she'd been teleported into a stone by a magic circle. There were any number of possibilities.
Teleporting inside a stone was supposed to be extremely rare, but conversely, that meant it did happen on occasion.
Hadn't Geese said she'd been with other adventurers?
No—he'd used the word "captured."
Hmm? Wait—had Geese known about this situation...?
No, that couldn't be.
There was no point nitpicking his word choice.
I could question him once everything was over.
Besides, that wasn't the real issue.
"...Is Mother alive in there?"
"What?!"
At those words, Paul shot to his feet and grabbed me by the collar.
"Who the hell cares whether she's alive or not?!"
"You're right."
Indeed.
That had been a careless thing to say.
Zenith's chances of survival had been low to begin with.
I'd even considered the possibility that we wouldn't find a body.
I'd hoped to at least recover a keepsake.
If she was dead, she was dead—I'd wanted at least something to mourn her by.
If she was preserved clearly identifiable as Zenith like that, then it was perhaps far better than I'd expected.
"Cut it out! No fighting!"
At Geese's shout, Paul leaned into my face as if to intimidate me.
"Rudi. Zenith was right there. Your mother was right there. How the hell can you be so calm about this?"
"Would it be better if I panicked more? Would flipping out solve anything?"
"That's not what I'm saying!"
I understood what Paul meant.
I was perhaps being too calm.
This wasn't exactly the reaction of a child finding a mother who'd been missing for six years.
...Well.
The truth was, I'd never had much of a connection with Zenith since I was young.
My sense of her as my "mother" was thin.
If anything, I thought of her more like a stranger I'd lived with.
After all, we'd been separated when I was seven, and nearly ten years had passed since then.
It was perhaps inevitable that I'd come across as cold.
"Let's assess the situation first."
"What?"
Ignoring Paul's intimidation, I calmly laid out what I'd observed.
"That guardian was immune to magic.
It has incredible regeneration, and its attack power is high enough to breach Elinariése's defenses with just a graze.
And our mother is trapped inside that stone.
To be blunt, we don't even know if she's alive."
"I know all that, dammit! I'm talking about your attitude when you find your mother!"
Paul shouted, and Geese cut in.
"I said cut it out! Have your family argument back at the inn!"
Geese forcibly pulled Paul away.
Paul spat, "Damn it, you bastard," and sat heavily on the ground.
He didn't need me to tell him—he understood the situation perfectly well.
It was just my attitude that rubbed him the wrong way.
I knew I was being too detached.
But what could I do?
What did he want from me?
"All right, that's enough fighting—time for a discussion!"
Elinariése clapped her hands together.
Paul and I shuffled into a circle.
Roxy watched the two of us with a slightly worried expression, glancing back and forth.
I'd apparently worried her.
"I'm fine."
"Are you...?"
This wasn't the first time Paul and I had clashed like this.
Once this was over and we were back at the inn, Paul would cool down.
And if Zenith was saved and I could hear her voice, I was sure I'd feel something too.
Yes, I was sure of it.
This time, things had just gone a little off the rails.
"Ahem. So, about Zenith's crystallization—I think it can be reversed."
Roxy's voice was slightly brighter than usual.
"Really?!"
Paul's face lit up with hope.
"Yes. I've read that sometimes, powerful magic-imbued items end up trapped inside mana crystals like that, and when you defeat the guardian, the crystallization dissolves and the contents are freed."
This was news to me.
But it was Roxy speaking.
Roxy wouldn't lie.
"I've heard the same."
Elinariése chimed in.
"I know someone who ended up in a similar state to Zenith, and they're alive and well today."
"..."
That had to be a lie.
Elinariése was prone to telling bold-faced lies in situations like this.
She did it to improve the mood, so I couldn't really fault her.
Still, even if there was precedent, the crystallization dissolving didn't guarantee the person inside was unharmed.
Of course, there was no need to say that aloud.
Everyone already knew.
"The real problem is that guardian... To be honest, even I've never seen this type before."
It was Elinariése who took the lead in addressing the issue.
Geese followed up.
"Yeah, you can tell it's a hydra at a glance, but I've never heard of a species with green scales like that."
"And it regenerates on top of that."
Talhand had his arms crossed, looking troubled.
A hydra was a type of dragon.
A multi-headed dragon that didn't form packs but was among the most powerful creatures when encountered alone.
I'd heard they inhabited somewhere on the Demon Continent.
There were at least three known species, distinguished by scale color: white, gray, and gold.
A hydra with green scales didn't exist.
"That's most likely a Multiscale Hydra."
Roxy spoke up.
"I've read about it in books.
A demonic dragon covered head to tail in mana-absorbing scales.
It was sighted around the time of the Second Human-Demon War, and was said to have gone extinct when the continent disappeared.
I'd always assumed it was just folklore, but... so it actually existed."
Mana absorption.
Which meant magic was almost entirely useless against it.
"Then you're telling me we can't deal any damage to it?"
"If what the book says is true, it should work if you hit it from point-blank range."
"Point-blank range..."
That massive body.
And you'd get mangled just by being pressed against it.
He wanted us to touch it directly and cast magic?
We'd lose all our fingers.
"But even if we did deal damage, it regenerates. What do we even do...?"
"Regeneration is the tricky part."
"...But we can't even talk about beating it unless we actually beat it."
The hydra regenerated.
Somehow, that didn't surprise me.
There was a general understanding that hydras regenerated.
"I lopped off two heads and they grew back in an instant. How the hell are we supposed to kill something like that?"
Roxy was groaning along with me.
But honestly, I didn't think it was as hopeless as they were making it out to be.
I'd never encountered a regenerating monster before, after all.
Why wasn't I more worried?
Because I had knowledge from my previous life.
"I actually have an idea."
When I raised my hand to speak, all eyes turned to me.
"I've heard that cauterizing a hydra's wound with fire prevents it from regenerating."
I told the story of the Greek hero Hercules.
Hercules had fought a hydra.
According to the myth, you could prevent regeneration by searing the wound with a torch.
Honestly, it was just a myth.
Its credibility was thin.
But the reaction was positive.
"I see... cauterizing the wound."
"We don't have torches, but if it's just about the wound, there's no worry about the scales deflecting the magic."
"Worth a try."
I had no idea how similar this world's hydra was to the one from my previous life.
The hydra from mythology was supposed to have an immortal head...
But maybe if we burned off all its heads here, it would simply die.
I didn't want to be overly optimistic, but it was a living creature—so death had to be possible.
"All right, let's go with that."
At Geese's words, a plan was decided.
My proposal was far from certain.
But certainty didn't exist anywhere.
Honestly, part of me thought we should go back to town first.
We'd barely used any of our stamina, but the enemy was formidable.
Maybe we should prepare specifically for a boss fight.
Hiring people just for a boss fight was an option too.
I didn't know how many swordsmen existed who could cleave those hydra heads in two, but with that many adventurers around, there had to be at least one if we looked.
"..."
But Paul would never agree.
If I suggested going back now, he'd probably say he'd challenge the hydra alone.
And besides, I doubted that going back would conveniently turn up items or mercenaries specifically designed to counter that hydra.
We had a countermeasure.
We had most of the personnel we needed.
So this was the moment to push forward.
"Hey, Paul. That works for you, right?"
"...Yeah."
"Bit of a lifeless response. You get that you're the only one who can actually cut off those heads, right?"
Elinariése and Talhand could probably wound it through the scales.
But they couldn't cleave through.
Paul would cut off the heads, and I—with my ability to cast without incantations—would cauterize them immediately.
That was the division of labor we needed.
Depending on the situation, I might have to get extremely close myself.
Even if I wanted to pinpoint just the wound, the surrounding scales would likely negate magic too.
If that happened, the other three would act as decoys to draw attacks away from me.
If a decoy got hit, Roxy would provide healing.
That was the only way.
Naturally, attacks would come my way too.
It was a dangerous position.
"Rudi..."
Paul's eyes turned to me.
He looked at me with a somewhat hollow gaze and spoke.
"You're... a really reliable son."
"Save the flattery for after we've killed the hydra."
"It's not flattery. I mean it."
Paul said that and let out a self-deprecating laugh.
"I'm just an idiot who can't stay calm like you, can't come up with ideas, and only knows how to charge in headfirst."
Paul continued.
His jaw tightened, the corners of his mouth twisting.
"...I'm a failure of a father. Doesn't look like I'll ever be a good role model for my son."
Paul spoke with a tone of quiet resolve.
His gaze was incredibly intense.
Eyes brimming with such force they could've pierced me.
Resolve.
Paul had steeled himself.
"Knowing that, I'm going to say this. I know it's not something a parent should ask, but—listen."
"Yes."
I met his gaze head-on.
"Even if it kills you—save your mother."
Paul said those words.
To his son.
Even if it kills you.
But I didn't think he was a terrible father.
This was trust.
Paul saw me as his equal.
That was why those words could come out.
All I had to do was answer that trust.
"...Yes!"
"All right, let's go!"
At Paul's words, everyone stood up.
The rematch with the hydra was about to begin.