The Key to the Depths
“You?”
“Yeah. Me.”
“That arrogant bastard…”
“No, I’m telling you it’s me. The final key to this place. Or more precisely, I should say the water spirit master?”
Until just a moment ago I had been uncertain, but seeing the inscription carved above the door made everything click. Those were phrases I had seen countless times in the ancient texts left behind by the old spirit masters.
Water spirit masters in particular had a noticeable habit of using the expression “to flow into.”
And there were a few quotes they especially loved to cite—a verse from a poem supposedly written by the gods themselves.
I had seen it so often that even someone as lazy as me had ended up memorizing it.
“Fate is like the sea. It is a vastness that cannot be altered by will, a great storm, and no one knows its end. Thus, one cannot know where it will flow, nor even where it currently lies. If you entrust yourself to the natural order, you will flow along with it. Both life and death will come to you in due time.”
“What does the fourth verse of the Poem of the Gods have to do with anything?”
“The quote is written on that door. It’s a poem water spirit masters are especially fond of.”
Lox clearly didn’t understand what I was saying.
“What does that have to do with you being the key?”
“Haven’t you thought about it? The entire path leading here has been demanding a water spirit master. Otherwise, it would have been nearly impossible to reach this place, wouldn’t it?”
“That’s… true, but…”
“The person who built this place was probably a water spirit master like me. The phrase ‘one who inherits the legacy’ refers to someone who possesses the same power. And the fact that there are no traps… maybe it’s because they wanted to pass their inheritance on to a successor walking the same path.”
You could tell just by looking at the letter.
Dungeon device theory wasn’t my specialty, but when it came to spiritology, I had more than a little expertise. No, to be honest, I was confident I was the best in the field.
“In the deep places where light does not reach, you shall find it by fate. The price of liberation is the fate of the lake…” There was a passage like that, right? I used to be confused about how to interpret ‘the fate of the lake,’ but if you think about it simply, it might just mean a fated person who can cross the lake.”
“A fate that allows one to cross the lake…”
“Right. In that case, it can only be me, can’t it?”
“…Alright. That does make sense. Then if you infuse mana into the device…”
“But I don’t think that’s the way. Unlike swordsmen, spirit masters don’t materialize mana. There’s no way they would have designed it like that.”
Swordsmen manifested mana as sword aura, shaped it, materialized it, and used it.
Extracting mana from their bodies was their method.
And using mana that way required more physical stamina than mental strength.
On the other hand, spirit masters and mages consumed mana directly from within their bodies when using their power, and that method consumed a great deal of mental energy.
The reason the two professions trained in completely different ways was precisely because their methods of using mana were entirely different.
There was no way they would have created a path tailored for a water spirit master and then made the door operate on a swordsman’s method.
“Then does that mean there’s another method?”
“If a spirit master made it, they would use a spirit. Undain?”
[Yes, Master.]
“Can you open this door? What exactly is the method a spirit master would use? We can’t attack it, right?”
Now that I thought back on everything, it all made sense. This place had been hidden somewhere that could not be reached without a water spirit master.
In that case, there was only one key the dungeon’s master desired.
The rippling blue lifeform right in front of my eyes.
[I can open it. What is compatible with this door is our power.]
“I knew it! Open the door for me. Undain, you know the method, don’t you?”
[Of course. Just as a fish knows how to swim and a bird knows how to fly… I instinctively understand it simply by looking. However, I cannot open it myself.]
Just when I thought things were going well.
My ominous premonition was never wrong.
“…So that means… perhaps… it’s that?”
[Yes. This door demands an existence greater than I. If you cannot summon him, it cannot be opened. That is both the trial and the trap of this place. But if it is you, Master, you should be able to achieve what you desire.]
“Haa…”
My goal for today had been to avoid overdoing it, but that plan had gone spectacularly wrong.
To think I had to summon that. Looking at it now, there weren’t any traps—the place simply demanded someone capable enough that traps didn’t even matter.
As I let out a deep sigh, Ash approached.
“Jeanie? What is the spirit saying?”
“…I can open it, but…”
“You can, but…? Is it bad news or something…”
Since the men couldn’t hear the spirit’s voice, they fidgeted anxiously, staring only at me.
Good grief, those are some baby-bird eyes.
Since I had dragged them all the way here, I supposed I should at least explain something before sending them off. What else could I do?
“I have to summon something big.”
“Big…?”
“Big?”
“What the hell is that supposed to mean?”
“We’ve come this far. I have to do it.”
Let’s treat it as an early birthday present for Ash. The Cup of the Golden Star—it’s perfect, isn’t it?
I gestured for the bewildered men to step back.
“You’ll see when you watch. Everyone move back. It’s dangerous.”
First, I should loosen up my waist a bit. And massage my shoulders.
I stretched and glanced back at the party members who had taken several steps back even though they had no idea what was happening.
The reason I smirked was because I could clearly picture how shocked they were going to be.
“You’ve all been curious this whole time, haven’t you? About what exactly a spirit master is.”
“I think I get the general idea now? Those blue guys flying around and shooting water droplets.”
“Isn’t it making it rain?”
“Crossing water? Building bridges?”
The more I looked at their stupidity, the more fond I became of them.
Was it because I was used to Rai?
To think that these bearded, burly, sweat-smelling men looked cute to me—I clearly had issues.
“While we’re at it, I’ll show you properly. Consider it an honor.”
It would be an extremely rare experience they would never see again in their lives. It would probably be harder to witness than the duel between Robenin and Count Trenpe.
I stopped showing off and stood facing the door, steadying my breath.
Summoning something enormous came with an equal amount of strain. As always, I would be suffering from a fever by tonight.
When would I finally be able to summon Endairon without any burden?
“O water that knows no mercy.”
Standing firmly on both feet, I prepared to call forth the power.
As I imagined grasping that power in my hand and spoke the incantation aloud, I felt something within me connect to a distant place.
Spirit masters called it a part of the soul.
When soul touched soul, we resonated for a brief time, becoming two yet one, and exerted our power together.
“From the raging sea, at the end of the vortex entwined with death…”
[Is he doing well these days?]
“Come to me, Endairon.”
The droplets that had been falling one by one from the ceiling suddenly multiplied into a torrential downpour. The ground shook violently as water began to boil up from below.
Everything around us rang out noisily. The waters flowing near the cave were clearly reacting and surging in response.
Water swirled violently around me, climbing up my body until it reached the ceiling, then spread in all directions. In an instant, the water rose to our knees.
Thinking we were being flooded, one of the party members suddenly screamed. From the voice, it was Lox.
The water didn’t stop at filling the floor. It flowed rapidly in every direction, crashing with powerful waves.
Then, suddenly, one section rose up like a head. It wrapped around all of us once before slowly lifting an enormous body large enough to fill the entire cave.
Even though the cave was wide, it still seemed narrow for Endairon. I had tried to summon him as small as possible, but there was no helping how cramped it became.
Before we could even process what was happening, we found ourselves standing between Endairon’s massive coils.
The currents of water flowing past us were part of his writhing, colossal body.
His majestic form—large enough to make humans feel like mere insects—curled its tail all the way up to the ceiling. A pair of black eyes, like staring into death itself, turned toward me.
[My friend.]
“Endairon, open the door for me.”
Just as Undain had said, did Endairon instinctively know how to open the door?
Endairon moved his massive body like flowing water and headed for the door.
Because there wasn’t enough space, part of his body crawled up the wall, but he didn’t seem particularly bound by floor or walls.
Right now he coiled himself into a round spiral above the door and began to enter it headfirst.
He was gradually disappearing inside through the spot where Ash had placed his hand.
The enormous dragon kept being sucked in for so long that it was hard to believe there was room for him inside the door. And at some point, I instinctively understood.
Yes. So this is how it works.
I could feel the countless mechanisms inside the door through Endairon.
Inside, there was one missing piece—the most important and largest spring. It was none other than the high-grade water spirit, Endairon.
I didn’t know who the previous owner was, but using Endairon as a key made it clear they had been an incredibly powerful figure.
I was already feeling strained just from Endairon filling the spring’s position.
“This is harder than I thought…”
[The ancients had high standards. If it is difficult, would you like to take the mana inside me?]
“Wait. Not yet. This much… I can do it alone. I can do it.”
I muttered as if making a vow.
Since it felt like I would be relying on Rai and Magi’s help just to open one door, I wanted to try doing it with my own power first.
Although it was long ago, someone must have opened this every single day. As a fellow spirit master, failing to do even this would be a serious blow to my pride.
I focused even more on the situation inside the door.
As Endairon, who had filled the empty space, began to move, the sound of mechanisms turning—click, clack—finally echoed from within the door.
Even turning the spring once consumed an enormous amount of mana and concentration, but I was the type of person who hated showing that I was struggling more than I hated actually being in pain.
The device inside the door would spin uselessly if I let my impatient nature make me try to move it even a little faster, forcing me to match its internal speed.
Naturally, both the time I had to concentrate and the mana I consumed skyrocketed.
“Jeanie…”
I had been so focused that I hadn’t even noticed Ash approaching.
He must have seen me sweating. He fidgeted anxiously and wiped the sweat from my forehead with a pitying look. Only then did I realize I had been biting my lip hard.
My lips were tingling, and sweat had pooled in my palms.
I opened my hand, clenched it again, and murmured softly.
“It’s almost done.”
“I’m sorry. This isn’t something you should have to struggle with…”
“What? You want to sap my strength by saying things like that?”
“But… you hate helping others, don’t you?”
Are you an idiot?
“Ash, you’re not ‘others.’ You’re someone who’s allowed to wipe my sweat. Those two things are very different.”
Did he really not know that?
Ash made a complicated expression that looked like he might cry.
After exerting myself to the point where I felt like I was going to die for the first time in a while, I grew slightly dizzy. Warning signs of internal injury made my stomach churn, but none of it felt meaningless.
Because after a long, stubborn contest of strength, the massive door began to open for the first time in thousands of years, shaking the entire space.