Crash—the books piled in Liam’s arms slipped straight down.

“Faiiiry!”

He rushed over and promptly scooped Rubian up into the air.

“Ah! The books! The books!”

“What is going on? How did you end up here? And aren’t we forbidden from acting like we know each other?”

“We are! Forbidden! This is a secret rendezvous between you and me...!”

“I absolutely love secrets just between the two of us.”

Liam pulled Rubian into a tight hug.

As he looked his younger sister over from top to bottom after seeing her again for the first time in a while, his eyes landed on her black bobbed hair.

“By the way....”

His eyes narrowed beneath his glasses.

“According to the rumors, your hair really does look as though you got drenched in the venom of some sea beast....”

“That is not true! It is not squid ink!”

Rubian bristled, but Liam only found his sister all the more adorable for it.

*****

“You want to go inside the Rare Books Archive?”

Liam asked as he pushed up his glasses with both hands. Sitting in the chair, I nodded.

“Mm-hm. I did ask Professor Yuliope... but she said no.”

Unlike the children’s collection room, the chairs here were high, and so were the desks. My feet did not reach the floor, so my legs kept swinging back and forth on their own.

“...Do you happen to know a way?”

The moment I asked carefully, Liam’s eyes, fixed on me from beside me, flashed.

“A Rare Books Archive key? Something like that would be easy enough to get. The patrol schedule of the guards nearby, and the schedules of the supervising professors as well....”

“Gasp.”

“All of it.”

Liam pushed up his glasses with a clever-looking face.

Long live obsessive teenage nerds! Long live bookworms!

“But... Professor Yuliope comes to the Rare Books Archive almost every night.”

“Huh? Really?”

“Yes. I don’t know what she does after locking the door, but for the past month, she has been staying there all night, so it has been rather troublesome....”

My eyes blinked once, then again.

...So the night Khalid and I snuck in really was absurdly lucky.

I thought it over once more.

It really must have been Professor Yuliope who came to the library so suddenly that night. If our timing had been even a little worse, we might have been caught much earlier.

“Hng, then what do I do? I can’t even stay here for ten days....”

And if I wanted to go all the way inside, to the part I had not managed to see, I might need to stay there quite a long time.

“Don’t worry.”

“Hm?”

“She will not be there two nights from now.”

“Huh? Really?”

“Two nights from now is the anniversary of the deaths of the fellow scholars she used to study the ancient language with. She will probably go out.”

Gasp, a chance!

“......” 𝙧𝙚𝙚𝔀𝒆𝓫𝓷𝙤𝓿𝒆𝙡.𝒄𝙤𝓶

Hm? Wait a second.

A sudden question came to me, and I leaned way in and stared hard at Liam.

“But how do you know Professor Yuliope stays in the Rare Books Archive all night? The library closes at seven....”

At that, Liam sprang to his feet.

“All right, since you need it, I’ll get you the key first.”

Hmm, this is suspicious no matter how I look at it.

Still, Liam was on my side, so I decided not to press him any further. I did, however, decide to add it to the report investigating what my two brothers were really doing at the Academy.

“How are you going to get the key? You’re not planning to sneak it out, are you?”

“What do you take me for? I can just get it from the caretaker’s office. Of course, every borrowed key is supposed to be recorded.... But, well, people do make mistakes sometimes.”

“...Amazing.”

I was impressed all over again.

And slightly sick of it.

Just how glued to the library do you have to be!

How had he managed to earn a permanent free pass to the library at that age?

“Then meet me in two nights. After seven.”

“Ehh....”

I fell into brief thought. Liam seemed excited by the idea of going into the Rare Books Archive with me.

Investigating alone would be best, but....

Well, nothing could be done for it right now.

The goal, for now, was simply to get inside.

“All right, Brother!”

I nodded with a smile.

Liam patted my head as if he found me admirable. Then he opened the book beside him and forced me to study.

*****

To get straight to the point, on the night two days later,

Liam was unable to go into the Rare Books Archive with me.

Because an elderly professor had suddenly barged in and said this:

“Liam! The ingredient analysis of the magical beast claw you brought me is done! We made an extraordinary discovery! It should be wrapped up by the evening two days from now. # Nоvеlight # Are you free then? We are about to leave our mark on the field of biology!”

Liam grabbed the professor and hugged him with a moved expression.

“Damn it, Professor, I believed in you!”

“Excellent! Then will you come to our university research division? Shall we make it official?”

“Anything, anything at all!”

Ah....

Just like that, Liam had crossed the point of no return.

“Ah, but I already have plans for the evening two days from now....”

“Brother, I’m fine. Go do your research. Your studies are more important!”

“Faiiiry....”

In the end, Liam, looking deeply moved, secretly told me where the key was and what the guard patrol schedule was. (How on earth does he never get caught!)

He also told me that if anything troublesome happened, I should say it had been under his name.

The library is not exactly a dangerous place, anyway.

It was a relief that Liam understood burning scholarly passion.

Anyway, after finishing dinner, I pretended to go to bed, then secretly slipped out of the dormitory and headed for the library.

Once I knew the schedules of the guards and the librarian on duty, sneaking in was easier than before.

“Ha, the oak drawer next to the magical-beast-patterned table.”

Walking ahead, Khalid muttered in disbelief. In one hand he held the gold key the squirrel had found and brought to him.

“Don’t you think? How is anyone supposed to find it in the middle of all that chaos?”

Khalid whipped around to seek my agreement.

“Shouldn’t somebody seriously file a complaint about this? Why is the caretaker keeping every kind of overnight supply in the office?”

I pressed my lips together, whistled lightly, and played dumb.

For some reason... I felt like I knew who the culprit was.

The investigation report...! More material to add...!

News that the eldest son was moving household supplies into the library! That might be hot!

In any case, I hurried along.

After a little while, my legs faltered slightly.

Ah, that stings....

The truth was, I had fallen during physical training this morning.

It was only a small scrape on my knee, but when I walked quickly, it stung a little.

If he notices, he’ll nag me....

I should just keep quiet.

That was why I had deliberately worn a long dress too.

Fortunately, Khalid seemed not to notice, since he was walking in front.

I moved as carefully as possible. After a while, the huge door of the Rare Books Archive appeared before us.

“It opened.”

When Khalid inserted the key and turned it, the large lock came undone with a click.

“Let’s go farther inside.”

“Okay. I’ll lead.”

We advanced without interruption all the way to the center of the Rare Books Archive, a place we had not managed to reach last time.

It feels like the magic pooled here has been preserving the books.

I thought that as I sensed the force thick in the air.

Yuliope had called this place “an environment optimized for preserving old books,” or “a mysterious blessing.”

Since she was an ordinary person who could not sense magic, she seemed to understand it simply as an indescribable force dwelling here.

It was when we had gone deep between the maze-like, chaotic shelves.

Khalid suddenly stopped walking.

“Ruby. Look at this.”

He turned toward me with an odd expression.

“What is it?”

“There’s a tree in the middle of the Rare Books Archive.”

“...A tree?”

I hurried forward.

The farther inward I went, the denser the magic became.

And at the deepest point of the Rare Books Archive,

there was a small courtyard like a glass conservatory.

“This is....”

An enormous ancient tree seized my gaze.

Bathed in moonlight pouring down through the great window in the ceiling, the tree gently swayed.

As if enchanted, I stepped closer.

When I placed my hand against the rough surface of the trunk, the blue leaves trembled slightly.

“Khalid, this tree....”

When I turned to Khalid beside me, my red eyes were reflected in his clear ones.

“Why is there a tree here?”

I answered quietly.

“...It’s a sealing tree. It seems to be holding the magic inside this space and keeping it here.”

“So that’s why only the Rare Books Archive was overflowing with magic.”

Khalid nodded, then suddenly furrowed his brow.

“But then, if that is true... could the reason the capital of Babilon is so lacking in magic be....”

My head slowly nodded.

“It might be because things like this are scattered all over the capital.”

But who in the world had done something like that?

I kept my hand on the tree and tried to learn more, but there was nothing more I could figure out.

But just touching it makes me feel calm.

I closed my eyes and felt the magic quietly circling. It was an incredibly soft, warm force.

Were the books being preserved well because of this sealing tree?

But something was missing.

Magic was, quite literally, only a source of power.

By itself, it was difficult to expect a specific effect from it. That was why various magic circles were needed to produce the result one wanted.

“Ruby, there’s a strange stone tablet here.”

Just then, Khalid’s voice came from behind the tree, where he had been looking around.

No way?

I immediately hurried over there.