Underneath the Old School Building lies a dungeon inhabited by monsters.
It’s not that all trustworthy comrades have become enemies—though such situations can occur.
Beneath the Old School Building, specifically under the library, exists a dungeon.
In-game, it is a challenge area that is difficult to clear unless you are playing a second round and are at least level 90.
From a lore perspective, it’s the entrance connecting the Demon World and the Middle World, sealed 500 years ago.
The Four Heroes of Humanity in this world’s setting risked their lives to block the “Exit of the Demon World” and sealed it with massive land barriers, building an academy over the seal.
To prevent anyone from even considering opening the “entrance to the Demon World” and allowing its denizens to spill into the Middle World, they left no records on the surface and sealed themselves within the magic.
For 500 years, fortunately(?), nothing has happened, largely because this secret has been under the management of Heaven.
‘The reason the Old School Building became what it is today is ultimately due to the angels’ scheming.’
The angels thought.
The angels feared the possibility of a reckless student discovering the entrance to the underground through an unknown expedition in the library of the Old School Building.
What if, by chance, they stumbled upon a “Grand Magic” created by the Four Heroes to ensure no human could reach the depths of the underground?
Humanity would undoubtedly challenge it.
With no records left by the Four Heroes, people might assume the Grand Magic was a trial left behind for academy students, a gift for humanity, oblivious to the fact that it was a seal desperately placed to keep everyone away.
‘Even the Church of the Goddess wouldn’t be able to manage this.’
The Church of the Goddess wouldn’t want the information to spread.
Most likely, they don’t even know that the entrance to the Demon World lies beneath the Old School Building; they only sense ominous signs and warn humanity to stay away.
The angels of Heaven descend to warn against approaching, though those angels nearby are unrelated to the specific dangers of the Old School Building.
Those angels are merely hedonists who borrow human bodies to indulge their desires. They have no noble mission to “protect the entrance to the Demon World.”
Unless they’re archangels.
Archangels, on the other hand, indirectly monitor the situation regarding the Old School Building through reports gathered via the magic panels attached to the instructors’ wrists.
‘The archangels possess the devout believers of the Church of the Goddess in their dreams to read the reports through their bodies.’
Through this method, they maintain real-time knowledge of the happenings, including the reports written by Instructor Esta and Instructor Kadisha.
Could they be persuaded to stop this surveillance? If someone were to bypass the angels’ watch and open the underground entrance of the Old School Building, clearing it would likely be much easier.
‘That’s impossible.’
In-game, it was possible.
Why? Because those who opened the Old School Building’s underground door were “Heaven’s Sentinels”.
These individuals were devout believers in the Church of the Goddess, unwavering in their conviction that Heaven was right, and the Demon World was wrong.
The protagonist and their companions didn’t breach the final seal and invade the Demon World out of mere curiosity.
In the game, the nuances of angels and the Goddess weren’t fully clear. Players weren’t aware of their ulterior motives and merely thought, “Ah, they’re using the player and allies as vanguards to destroy the demons.”
The angels didn’t block them from clearing the Old School Building’s underground library, known as the [Old Library], cheering instead of intervening.
Now, however?
‘They’d be worried.’
The situation is ambiguous.
The student—disciple of the Grey Witch, the Cutting Wind, and the princess of the Di Ercy Empire—would undoubtedly attract their attention.
‘Well, even if the last one might be uncertain, compared to other imperial princesses, she doesn’t seem to be a huge variable.’
In this continent, those who do not worship the Goddess are close to heretics.
As long as you don’t outright deny the Goddess or claim she’s wrong, not believing in her is grudgingly tolerated.
And then there’s [Phoenix Ludvecia].
A being who suddenly appeared.
The Angels in Heaven might not be able to pinpoint where this being came from.
Or perhaps they do know.
But guessing—
‘It’s not a being that emerged from the Demon World below, but something that fell from outside their perception, like from another world.’
They probably think so.
From a planetary or cosmic perspective, my appearance would look like some extraterrestrial entity crashing onto the surface as a comet, rather than something rising from underground.
If they observed what I did right after I arrived, it would seem as if an alien entity was absorbing knowledge from surface dwellers to sustain itself.
In other words.
They probably think I’m more like an alien than a denizen of the subterranean Demon World.
So they would be worried.
Worried that I might attempt to conquer the ancient Library and fling open the sealed entrance to the Demon World.
If any such movement is detected, the Angels will definitely intervene.
Whether by having an Archangel break their wings and possess an Esdinas Academy undergraduate to approach us or some other means.
Or, perhaps, they might disguise a loyal servant of the [Church of the Goddess], a [Saint], as a regular undergraduate and infiltrate the Academy.
Since there’s a possibility of such approaches, we must do everything possible to conceal our access to the [Old Library].
The first step is to win over the instructors but avoid relying on their direct help.
To persuade them, I created a situation where they could safely remove their magic panels—devices that alert faculty to potential dangers if not worn continuously—for short periods.
The solution? Massage therapy.
At certain times, the two instructors would receive massages from Phoenix. During these sessions, they would temporarily remove their magic panels to avoid bothering other faculty members.
The first time, they might be startled.
The second time, they’d be suspicious.
By the third session, they’d wear their magic pads during the massage, coughing awkwardly and thinking about the need to consider others.
By the fourth or fifth time, it would become routine. They’d take off the pads for about an hour without raising any suspicions, even if we discussed confidential matters during that time.
* * *
[A Little While Later]
“So, you’re saying there’s a hidden dungeon beneath the [Old School Building]?”
“Yes.”
I had called Instructor Kadisha, who had just returned from filing a report at the main Academy building. She sat next to Instructor Esta, listening intently with a serious expression.
“Why do you insist on keeping this secret from the Academy?”
Kadisha gestured to her empty left wrist.
Like Esta, it was known outside that this was their “massage time”, so they wouldn’t be contacted even if their magic pads were off.
“I’m unsure of the threats inside, but we want to monopolize the experience points we can gain from it.”
“Experience points, huh.”
Though it’s a game term, it applies well beyond gaming.
“True. If there are A-rank monsters swarming inside, the experience of facing them would be invaluable.”
How many chances does one have to face A-rank monsters in a lifetime?
Even our special class, privileged as it was, only had the chance to tackle three A-rank monsters during a month-long expedition to the northern contaminated zone of the Marquisate of Ludvecia.
Most of the other groups didn’t even face A-rank monsters because their plans were rejected by the instructors.
During the past three training sessions, not a single training group has faced an A-class demon.
“If my hypothesis is correct and the [Old Library] is ‘that place,’ the Academy might convert it into a public dungeon.”
“……”
“Wouldn’t that be the case? If no one knows, it’s a monopoly. If everyone knows, it becomes a ‘privilege.’”
“Hmm….”
“Even at this stage of conjecture, the value of fighting A-rank monsters—let alone higher ones—makes the place worthwhile, even if it doesn’t yield [magic stones]. The combat experience alone from fighting such elite creatures would be—”
“If descendants of those monsters from 500 years ago are still alive, it’d be an excellent chance to study their weaknesses.”
Instructor Esta interrupted, looking regretful.
“Five hundred years ago… the [Age of Chaos], when the [Demon King] ruled, and humanity struggled to survive. You’re saying the monsters of that era exist in the [Old Library] as ‘phantasms’?”
“Yes.”
This is a spoiler that only players in their second playthrough would know.
“It seems the [Old Library] houses the ‘Trials’ set by the Four Saints.”
To phrase it in a way that people of this era would understand:
“Perhaps it’s a space of illusions where Academy students can experience the trials faced by their predecessors and become heroes who can defeat any monster.”
Convincing, isn’t it?
“It’s a trial ground created by the founders of the Academy for the sake of future generations.”
Though in reality, it’s a bit different.
“I’d like to name this place the [Seven Star Trials—Pandemonium].”
“…Alright, I get it.”
Kadisha smirked and gestured toward Esta.
“So, she’s not allowed, but I am, right?”
“Yes.”
“…”
Esta pouted.
“Ah, the woes of being S-rank.”
“Oh, come on! I’ll just participate as an operator or something~”
The [Old Library]. The Dungeon Library.
“If I claim to be researching [Magic Engineering] alongside Instructor Kadisha in the library, no one will suspect me entering the [Old Library].”
After all, it’s not unusual for the Academy’s top student to start showing graduate-level initiative during their first-year summer break.
“But, you know, this trial of yours… Isn’t it just a legend? Couldn’t it just be your hunch?”
“If the trial doesn’t exist, I’ll quietly become a graduate student.”
“…Oh.”
The deal was struck.
“Student Phoenix? Better start drafting your thesis topic. I’ll get your library access permit right away.”
I’ll risk my position as a graduate student to open the gate to the Demon World.
If I fail…
I’ll just become a graduate student.
