After giving instructions to Pigi-maru, I sat down on my sleeping bag.
"Sorry for always making you play the decoy role, partner."
"Pi♪"
Before lying down, I checked the sleep gauge.
After confirming it, I turned my back to Mist and lay down.
We were still in the middle of conquering the ruins.
I wanted to avoid any chaos from her identity being revealed right now.
Mist—Serath Ashrain.
There were still some things about her that I hadn't fully sorted out in my mind.
But even if we were going to discuss it, another time would be more appropriate.
At the very least, after we returned to the surface.
For now, my priority was to secure the target material.
The question was whether she had noticed my [Sleep]...
I waited on my side for the effect to wear off.
"..."
It should be about time for the effect to end.
I closed my eyes.
"Nn――...eh?"
A small, high-pitched sound like ultrasonic waves reached my ears...
The circlet and equipment that had vanished must have returned.
Perhaps the illusion automatically restored itself upon waking.
"No way...did I fall asleep without realizing...? But——"
I sensed her stirring.
"But the contract time should still have some duration left...why?"
Contract time?
Was it some kind of price for contracting with a spirit that prevented Mist from sleeping?
Next, I sensed relief.
She must have confirmed I was asleep and relaxed.
Good.
It seemed she didn't remember anything about [Sleep].
Pigi-maru's distraction must have worked.
"――...pyu?"
"Pigi-maru-dono? Did you perhaps fall asleep as well?"
"Pi."
Pigi-maru was a monster that didn't sleep...I believed.
But right now, I had asked it to pretend to be asleep.
"I see."
Mist exhaled in relief once more.
Pigi-maru hadn't seen the changes to her face or equipment.
She must have concluded that from this.
"Piii〜♪"
"Wh-what's wrong? Could it be...you're lonely because Hati-dono is asleep?"
"Pi! Pi♪ Piii〜♪"
"Um, I'm sorry. Could you please refrain from touching my body too much...especially my face..."
"Pi...piii...pyuuu〜..."
"Ah, no! It's not that there's anything wrong with you, Pigi-maru-dono...!?"
Pigi-maru faithfully carried out the instructions.
It raised its voice loudly as directed.
And Mist made a bit of a fuss too...
This made it easier for me to "naturally" wake up.
I stifled a yawn.
Tears welled at the corners of my eyes.
"Nn...what's up, Pigi-maru? Why the commotion?"
I sat up and rubbed my eyes.
Mist noticed me.
"Ah, I'm sorry. Did I wake you?"
"No problem. Still, sorry for not waking you when the time came like I said."
"No, please don't worry about it."
Her face had returned to normal.
So had the circlet and equipment.
My fake sleep didn't seem to have been noticed.
Perhaps the only material she used to judge lies was "voice."
"Did you manage to rest a little?"
"...Yes. Thanks to you, I was able to rest somewhat. It seems...I hadn't fully realized just how fatigued I was."
Mist gave a wry smile.
There was still some awkwardness in her expression.
She was supposed to be unable to sleep, yet her consciousness had briefly dropped.
She seemed to feel a slight sense of discomfort about that.
But for now, since her identity hadn't been exposed, she appeared to accept it as fine.
"Sleep is important."
I had learned that the hard way in the abandoned ruins.
"Yes. Whenever possible, I'll make sure to get as much as I can."
"Yeah, do that."
We prepared to depart and left the room.
▽
We descended to the next layer down.
"This layer alone feels like there's a lot more underground luminous stones."
Mist answered while staying alert to both sides.
"Yes, it does seem that way."
Perhaps even the short sleep had been effective.
Her movements were sharper than before.
"The corridors feel much wider too. Does the increased width mean more stones?"
"I've heard that luminous stones tend to form in places with high magical essence density..."
There had been more luminous stones on the upper layers.
So the surface had denser magical essence?
"Looking at it another way, could this layer be something special?"
"Possibly."
I wanted to believe we were getting closer to the target material.
"By the way, there's something I've been wondering about."
"What is it?"
"Do the hidden staircases and opened doors in the ruins automatically close themselves?"
The Great Sage must have discovered the bone powder of the target material in the depths of this ruin.
That meant he must have opened that hidden staircase.
Yet the mechanism had reset to its original state.
"The restoration of mechanisms in ancient ruins is generally explained by the existence of 'ruin repair ghosts.' That said, it has never been proven, so the truth remains unknown."
"Repair ghosts?"
"It is said that every few decades, spectral entities appear in various ruins to repair and restore their functions. Nowadays they are considered a type of spiritual monster."
It sounded like someone had slapped a rational explanation onto the occult.
Or perhaps they really existed.
I stopped in my tracks.
"That door."
I pointed ahead.
A massive door.
Extremely wide.
Mist stepped in front of me.
"It has the atmosphere of something significant——please be careful, Hati-dono."
A door paved with bones, perhaps.
It was a grotesque bone door.
My target was the bone powder of the Skeleton King.
"..."
The target monster might be close.
"One side of the door is already open..."
The bone door had one side already ajar.
I peered intently into the depths.
But from here, I couldn't see much.
We approached cautiously.
Mist and I peeked inside from either side.
A room with bones embedded in the walls.
No——bones were piled up along the walls.
A large quantity of what appeared to be monster bones.
Human bones seemed mixed in as well.
No monster presence inside the room.
We did a light exploration.
Nothing noteworthy besides the bones.
The only thing that stood out was that the luminous stones were orange.
Hm?
I crouched and touched the floor.
"Hati-dono?"
"The room's owner might be out."
Upon closer inspection, there were drag marks on the floor.
As if something hard had scraped across it.
Some of the traces looked relatively fresh.
Were these left by the monster that had been in this room?
Judging by the depth of the gouges, it was huge...
Had it opened the door and gone somewhere?
Hmm.
It didn't necessarily wait around for explorers.
"What shall we do, Hati-dono?"
"We go look for it. It might be the target monster."
We left the room.
Then,
*Boom*
"Did you hear that sound?"
"Yes."
"Pi."
The sound was distant.
But,
"Our trespass might have been noticed."
It was approaching.
Probably only one.
"――Iiiieee――Giiiieee――"
A roar echoed from afar.
Perhaps due to the structure of the passage.
The roar, which resembled a scream, echoed strangely.
This made it impossible to pinpoint the location by sound alone.
"Hati-dono, what's our next move?"
"We move to a spot good for observation. For now, let's head to the area near the stairs leading up. That spot had terrain easy to hide in."
"Understood."
The monster's strength was still an unknown at this point.
No...
We didn't even know for sure if it was the Skeleton King yet.
There was the precedent of the Soul Eater.
We couldn't afford to let our guard down.
We began moving.
Along the way, we emerged into a wide floor.
The ceiling wasn't particularly high.
If we passed through here, we would reach the target——
*Crash, Gaaaang――――!*
The wall burst open, and the monster appeared.
Flying debris from the wall and luminous stones scattered in an instant.
In that moment, I understood.
"This thing."
Its level of strength was on a completely different scale.
It was incomparable to the other monsters in this ruin.
Mist's expression tensed.
"No way, this monster——"
She seemed to recognize it.
"Skeleton King...!"