A short while later, Librarian concluded her rapid-fire overview of the situation and returned to me to report it.
"―So, it really was the game's OST that was playing?"
[Certainly, that's correct! Depending on the category of publicisation an Illusory World belongs under, or the source material to put it simply, there might be such additional effects like the music you experienced earlier! Erm, I didn't realise it was a concern until now, my sincere apologies...]
It was a concept the purpose of which I didn't fully understand, but if that's how it was, I thought I could get used to it.
If it was only music, then there shouldn't be any problems anyway, right?
"No, it's fine... but, if I'm inside the game's world, how can I hear its music? No one else can hear it, can they? You said it was related to the Library's Authority, but what does that actually mean?"
[Certainly! Ordinarily, as such concepts as a source material's soundtrack is something that exists outside of the bounds of the Illusory World, someone residing within it would never learn of its existence. However, because the method we use to transport you is with the Authority of the Library, you currently reside in a state that technically does not exist within the standard bounds of the world, but alongside it.]
[Perhaps it might sound complicated or convoluted, however, you can simplify it by knowing just that the Authority is protecting you in a veil of World Stability, I suppose...]
[Erm! Put another way, as you suggested, the music does not truly exist in the physical Illusory World, but rather as a fundamental part of the Illusory World's essence―and because you are attuned to that essence with the Authority, you are therefore able to perceive the music that exists within that essence also! As your Tier of Authority also increases, you should be able to perceive more and greater things that exist within the essence! I think!]
In the end, it turned out like such a specification was the cause behind the abrupt sonata.
It was confusing, but I gradually became able to understand it as my brain digested the explanation, at least to an elementary level.
Still, being able to hear the music of the game while I was inside it? It sounded crazy, but again, if all it really was, was music, then there wasn't really any harm done by hearing it.
I could think of it as no more than a quirk of the Illusory World, is all.
"Since it never happened before now, I guess it only happens when the Protagonist is nearby...? Or no, whenever a 「scene」 that includes the Protagonist starts."
'After all, that's when it would occur in the game, so it makes sense that I would only hear it then, too...'
"...Or wait, no. That can't be right."
―But, in that case, why did it play when 'I' hugged the Protagonist?
After all, "Enki Valentine" was never included in the original game, so there naturally wouldn't have ever been a 「scene」 in the game that included me.
Logically, this should mean that any event that occurs with just the Protagonist and me shouldn't have any music playing, because it technically isn't a 「scene」 that exists in the source material...
Nevertheless, music did play, meaning the interaction between us was somehow recognised as a 「scene」 by the world... right?
"I don't get it..."
[Enki, bear it in mind―You may be in the 'world of the game', but you are not in the game itself. This is merely an Illusory World fabricated to replicate the source material, and although it is a perfect copy of the source material's original setting, it is yet not the identical thing, but a mimicry. That is precisely why such elements as the music only exist in the essence and not in reality. Do you understand?]
The Librarian's voice echoed in my mind for a few moments, and as it did, it felt like I had been struck over the head with a hammer.
"Ah... right, that makes a lot more sense now that I think about it."
Because it always stated whether the world of the Contract was a book, T.V. series, game or whatever, it put me under the impression that I was in the actual source material, but that wasn't it at all. Even though I feel like I had been told that already...
Then, since these Illusory Worlds were fabrications of fiction, mustn't that mean they were physical worlds that existed somewhere in the real universe?
That's why I was even able to visit them in the first place, and why they have different measurements of time compared to Earth. Why all the people and places in them―why everything I've seen, heard, touched, smelt and even tasted has all been so palpable and undeniably real.
Even though, at some point, didn't I... For some reason, I recognised that I was accepting the fact abnormally easy, but somehow, it just made sense that that's how it would be, like a weird amalgamation of conflicting perspectives that didn't feel right.
As the Librarian said, that was also why it's impossible for in-game OSTs to exist in the physical world.
Since the physical world is still connected to the source material through the origin of its creation, the music exists within the so-called 'essence of the world'―the World Stability―is that it?
So, the worlds themselves weren't pure fiction, but real.
At the end of the day, they were likened to illusions, but weren't they infinitely more real than even the source material they were based on? In that case, it also meant Protagonists were real, tangible threats to these physical worlds.
The three Protagonists I had "dispatched" until now, were all real.
Accordingly, if I hadn't had done that, an entire world or even three could have collapsed.
Is that――really how it is?
[Ahem! Fret not, Enki! The objective remains the same, regardless of shifts in your perception...!]
Feeling one end of my lips curl up in some unknown, subdued emotion, I lightly shook my head in response to the Librarian's attempt at consolation.
"Nothing's changed about my perception. You already told me from the beginning what would happen if the Protagonist succeeded, right? This is just a reminder of what I already knew... it's not like anything's changed at all, really."
I didn't let the pressure of what would happen if I failed to kill a Protagonist get to me.
Well, to be honest, there was no real need to feel pressure in the first place, whether what I just "came to understand" was actually true or just my own delusion.
As I've said before, it honestly didn't affect me either way if these Illusory Worlds collapse. Even if they are real, I could just go back home, forget about it, and move on...
Nevertheless, if I wasn't able to stop the Protagonist from winning, that would be an unmistakable failure on my part, and it goes without saying that that's not something I would want to happen.
Besides, I have something to gain if they don't collapse, so of course I'd feel that way.
And, in that regard, it would be far more efficient to spend time contemplating something useful, such as how to raise my chances of success to the maximum.
'Hm? Wait.'
That's when it occurred to me. A question that, in hindsight, I couldn't believe I hadn't asked until now.
"Something's... gotta be behind the creation of all these worlds and Protagonists, right? They can't just be popping up out of thin air..."
Wasn't that a rather important thing to know?