Laila and Eustar did not know what Muge was saying or what she was trying to do. They simply watched her actions intently from a few steps back, as if observing a play.

Muge paused for a moment, holding the green key in her hand, as if in contemplation.

Then she made an angry expression, as if having a staring contest with empty space, and opened the palm of her hand that wasn’t holding the key. It was a movement as if there were an invisible wall or door.

“What is she trying to do?”

Eustar whispered. Laila shook her head, and at that moment, Muge pretended to insert and turn the key she was holding in her other hand into an invisible keyhole.

Now it looked like she was using all her strength to ‘push’ the empty air, and her efforts to turn the key didn’t look like an act at all.

— Click!

A sound loud enough to startle Eustar and Laila, who were watching, rang out. It was similar to the sound of opening an old, rusty, and heavy lock.

Muge, sighing, slowly pushed the empty air. Surprisingly, the space split open, revealing a completely different place before the three of them.

“This is……”

Eustar groaned softly. Laila was so shocked that she forgot to say anything and just opened her eyes wide. Beyond the space that had opened just like a door was a massive bookshelf.

Rows of bookshelves stretched out, with no visible floor or ceiling, making one wonder if there was even an end. Among them were countless books so enormous that even two or three strong men together would struggle to lift them.

Muge sighed again. It was the weary breath of someone who had just finished a hard labor. She tapped the edge of the open space—if such an edge existed—with the tip of the key.

Then something suddenly appeared from inside the space.

“Lady Olga!”

When it spoke, this time Laila also made a gasping sound. It was a strange creature that looked like a mushroom stretched long and then crumpled randomly, with a blue body about a hand span in length.

On its back were four, no, six thin wings, each fluttering at different speeds depending on their height. The sound of a bee’s wings, a dragonfly’s wings, and a swan’s wings could be heard simultaneously.

“Lady Olga! My goodness! Why did you open the door after so long? I missed you!”

“Don’t make a fuss.”

“I really missed you! ‘Pureungi’ cried and cried because he missed Lady Olga!”

Pureungi. Laila unconsciously repeated the strange name in her mind. The name ‘Pureungi’ wasn’t odd considering its bluish-green body, but…

‘No, it is strange. Who on earth gave it that name?’

The creature, whether a fairy, a spirit, or some new life form that magicians had created as a hobby and then crumpled up, flew around in circles.

Every time it spun quickly, sparkling powder scattered from the tips of its wings. It looked like the scales that fall when a moth flaps its wings.

Muge said,

“I called you because I have something to look for.”

“Just say the word! Pureungi can find anything for Lady Olga! I can even find a spell to wake a giant dragon!”

“I don’t need that. Bring me a list of magicians who left the city from 7781, ten years before and after. It doesn’t matter whether they were exiled or left voluntarily.”

“Magicians who left! Yes, I can find that! Pureungi knows exactly where that is!”

The spirit—she decided to think of it as a spirit—that was fluttering around energetically waving its limbs—if they could be called limbs—suddenly drooped its head dejectedly.

“But Pureungi is alone… If Lady Olga were here, we could do it together, but now there’s only Pureungi here. So it will take a little longer.”

“That’s okay. I’ll wait.”

“And, and! Lady Olga! Sir Sigrid misses you and…!”

The high-pitched voice that had been squeaking was abruptly cut off as the invisible door closed.

Laila thought the strange creature might knock on the door, but it was quiet.

The space that had split open like a dream had now returned to normal. The only thing out of place was the green key Olga had been holding, which seemed to be firmly locked into something in mid-air.

Muge, who had been making a gesture as if pushing empty air with both hands, suddenly turned her head to look at the two.

“You heard, right? Wait a bit.”

After a moment of silence, Eustar said with a dazed expression,

“Wait a minute, this can’t end with just ‘wait a bit.’ What was that just now… Magic? A magical tool?”

“Something like that.”

Muge flicked the key floating in mid-air with her finger.

“This is one of the keys that can open a door to the city’s ‘library’ anytime, anywhere. In the city of magicians, there’s a place called the ‘library,’ which they call ‘doseogwan’ among themselves. What you just saw was part of the library.”

“One of the keys, you say? Are there more of such keys?”

Muge snorted as if she had heard the silliest question ever and narrowed her eyes.

“Don’t you know how heavy a magician’s behind is? Magicians are the kind who hate even walking out to their front door. And they’re the ones who have to read books with every breath they take. Do you think they would go back and forth to the library to find books they need to read? Like humans? Say something that makes sense.”

Laila said,

“Then… does that mean all magicians have such keys? Are there that many doors to the library, or… doseogwan? Whatever you call it, that space?”

“Have you become a fool hanging around with that idiot? Kristrad, if you call yourself a witch, you should be able to figure out that much. Where did I just open a door? Did you see any door that I opened?”

I see. Laila suddenly realized the meaning of the ‘door’ Muge was talking about.

It was just a symbolic expression, not referring to an actual door. In other words, magicians could ‘open’ any part of the library with that key, and presumably could take out books that were inside.

Muge said,

“What you just saw is a spirit of the library. I don’t know whether it was born from books or in the library, but there are many similar ones. In the past, they caught all those troublemakers who used to tear books and eat letters, and bound them to the keys. One spirit per key. When you open a door with the key, the spirit bound to that key appears and runs errands for you. That’s how it works.”

“So that blue mushroom-like thing is the spirit of that key?”

‘Eustar had a similar thought.’

Muge cackled.

“Yes, that’s right. Spirits need to have names. Especially ones that are… bound to something like this. The person who has the key has to give them a name.”

Eustar said,

“So you’re the one who named it ‘Pureungi,’ Muge.”

“What, you have a problem with that? As you said, it’s blue, so I named it Pureungi.”

She looked as if she would immediately punch him and make one of his eyes blue if he said he had a problem with it. When Eustar shook his head, Muge snorted briefly.

Then Laila cautiously spoke up.

“Olga, there’s something I’d like to ask.”

“What is it?”

“That place we just saw… the magicians’ library. Are there many books there?”

Muge blinked and let out a dry laugh.

“It’s not just many. Do you know why magicians don’t live in the library and carry around these keys, which sometimes get left anywhere and swallowed by chickens, so we have to dig through chicken droppings to find them? That library has everything. It’s a place where books that don’t exist in this world exist. Do you understand what I mean? Magicians don’t enter the library directly. Even if they do, they don’t stay for more than a month. They can’t handle the energy of the books. They don’t stay for more than a month, and if they’ve stayed for more than ten days, they don’t read any text and clear their minds for a month. There are quite a few who went mad because they didn’t follow that rule.”

Laila wasn’t interested in whether magicians went mad or not. What captured all her attention was Muge’s words about ‘a place where books that don’t exist also exist.’

“Then there must be witches’ books there too.”

“Of course. There was a time when witches and magicians had quite a bit of exchange. It was before the Dark Age, so it’s ancient history even to me.”

Muge, who had reflexively answered indifferently, looked at Laila’s face with renewed interest.

“But why? Is there a book you’re looking for?”

Laila nodded hastily.

“There is. Among the witches’ books, there’s one that can read the devil’s seal… I’m sure such a book exists because my mother had it too.”

At that moment, Eustar’s gaze moved to Laila, and Muge’s gaze moved to Eustar. The reason she was looking for that book was obvious.

Laila had searched all the archives in the royal palace and, with Mel’s help, inquired about people who collect old books, but couldn’t find that book anywhere.

Her anxiety that it might have been a book passed down as a single copy among witches grew day by day, and she was beginning to despair that she might never be able to read the contract seal engraved on Eustar.

Muge said,

“The books in the magicians’ library include some that actually exist, but most are just ‘what was recorded’ taking the form of a book. I’m not sure if you can understand this… but, well, yes. If you look, it should be there.”

“I can’t go and look for it myself, right? I mean… can’t I read it? Um, like borrowing it for a while, as we do in the royal archives?”

“Unfortunately, that’s not possible. You’re not a formal magician, so it would be difficult for you to enter the city, and even if you could enter the city, it would be hard for you to withstand the energy of the library. If there’s content you need, I’ll have it looked up for you, so wait.”

A look of disappointment flashed across Laila’s face. Noticing that she was about to ask again, Muge waved her small hand dismissively and pretended to yawn.

“Enough, I need to rest a bit. I get drowsy and my body feels languid after replenishing my magical power. I don’t know when that fellow will find the records. It could be in an hour or two, but it might also take a day or two. So you two go somewhere and wait. I’ll call you when it’s found.”