The party skillfully opened a door behind the main entrance on the first floor of the main building and entered. The space, usually not open to students, began to reveal itself beside the corridor. Mesmerized unwittingly by the sight of the empty banquet hall and large hall, the students of the Black Tortoise stared in awe. They wondered why, despite such places, they had to eat hard bread in the lounge.

Yi-Han and Ratford exchanged glances.

-"Don't let your guard down,"- one warned.

-"Of course,"- the other agreed.

Ratford recalled the thief's creed: "When revisiting a place once burgled, be several times more cautious."

Yi-Han thought of the skull principal.

Since the underground passage was breached last time, he must have changed and strengthened the defense system.

They could not expect the luck of entering the underground without a trace, as before.

Click.

As expected, they saw a suit of plate armor walking towards them from far down the corridor.

-"How can you confuse me with a freshman?"-

-...-

When it was discovered that Lee Han and Ratford had succeeded in escaping through the passage of the underground warehouse, the warehouse keeper was called in by the principal and reprimanded.

Yet, the warehouse keeper remained unshaken.

-"But, even so, it's impossible to distinguish by the amount of mana,"- he protested.

-"Foolish... Fine, I understand. There's no immediate fix for this,"- the skull principal conceded.

He couldn't reprimand the warehouse keeper too harshly for missing Wardanaz this time; the warehouse keeper was too competent. More than just managing the underground warehouse's inventory, he was responsible for facility maintenance and various other tasks. Occasionally, he even caught unlucky students roaming at night. One mistake was not enough for further reprimand.

Honestly, even the skull principal considered this mistake unavoidable. Who could have predicted a boy from the Wardanaz family, an anomaly, would appear before the warehouse keeper who distinguished intruders by mana?

-"I'll lend you my summon. Don't rely solely on mana; find other ways to detect intruders."-

-"Yes, I'll do my best."-

-"If you find the boy from the Wardanaz family, don't let him escape. Send him straight to the punishment room."-

-"Why must I do that?"-

-"Just do as I say, will you?"-

After the conversation with the principal, the warehouse keeper significantly increased the security at the back of the main building and the underground.

To the students, it was like a game of cat and mouse. Once they found a way in, they kept coming back. So, a harsh lesson was necessary.

-"Don't even dream of coming this way!"-

The summon lent by the skull principal would surely catch the fearless intruders.

The warehouse keeper started his routine inspections, following the designated path.

"It's a walking suit of armor!" The students of the Black Tortoise whispered in terror.

"Do you know it?"

"I've encountered it before."

The students shivered. How many had been captured because of that walking armor?

Since it wasn't a person inside, attacking it fiercely only resulted in it reassembling itself, and if they managed to immobilize it, it soon called for reinforcements.

Yi-Han pondered, Is there a way to capture it?

The summon reminded him of Giorvan the Second, the guardian of the previous desert arena.

The summon was of a non-living, inanimate type. However, being non-living did not equate to invincibility. If it sustained significant damage, the summon would be forcibly unsummoned. The problem was...

Lightning element magic seems effective, but using it now would be problematic

Winning or losing the fight wasn't the issue. Engaging in battle meant certain loss for the students. Especially using loud, flashy magic like lightning element would be akin to announcing their presence.

It's better to avoid it.

"It seems we haven't been discovered yet. We should avoid it. Has it followed us well?"

"I'm not sure. It depends..."

Yi-Han decided to retreat with his party.

Click.

But, another suit of plate armor had already appeared far behind them. The faces of the Black Tortoise students turned ashen.

"I'll lure it..."

"To the side!"

Yi-Han didn't hesitate and opened a door. It was one he had noted for escape when they had first entered the corridor. An old space, probably once used as a classroom, appeared. Chairs and desks were stacked with various clutter.

The Black Tortoise students instinctively scanned the clutter for anything useful - a professional habit.

"If the armor enters here..."

"I know, Wardanaz. Scatter and run, even if someone gets caught?"

When faced with an insurmountable crisis, the principle was to minimize damage by scattering and fleeing.

The Black Tortoise students already knew this rule.

"No. I'll cast magic to knock it down. Don't be surprised and just run. It'll be very loud."

"..."

Hearing Yi-Han's confident plan to take down the armor, the Black Tortoise students thought, We brought the right person!

Not many would dare to speak of bringing down the armor. The Black Tortoise students felt fortunate to have him.

Thunk!

?

A clattering sound came from the clutter behind. The tense students turned in surprise.

"Did you touch it?"

"No... you?"

Paper and a quill appeared, then words were etched onto it.

-Can't you keep quiet, freshmen?-

"A... a ghost!"

-Not a ghost, but a senior. You foolish freshmen.-

The writing on the paper stopped the students' shivering, but they were far from reassured.

"Why are you... doing this, senior?"

"Yeah, show your face."

-Don't talk nonsense. I don't want to go to the punishment room. This is risky enough!-

"...?"

Yi-Han was momentarily puzzled.

Ah. Contact with a freshman leads to the punishment room by the principal.

Such a thing was very much within the realm of the skull principal's actions. Otherwise, there would have been cases of students contacting seniors.

-Anyway, keep your voices down and converse in whispers. If you don't want to be caught by that armor. And don't spout nonsense about a freshman using magic to knock it down!-

Yi-Han slightly regretted his words after hearing the unknown senior's admonition.

Was it too reckless?

"I thought lightning element magic would suffice... Sorry."

-...You know how to use lightning element magic?-

The other party seemed slightly taken aback. The handwriting trembled.

-Still, don't do it. It's too noisy. I'll get caught too.-

Yi-Han and the Black Tortoise students realized how precious this encounter with the senior was. When would they have another chance to converse with someone who had been in the academy longer?

"Senior, how can we evade that armor?"

"Senior, what's the best route to the kitchen from here?"

"Senior, what's likely to be on the <Basic Imperial Geometry and Arithmetic> exam?"

The sudden barrage of questions seemed to fluster the senior.

-Am I here just to answer your questions? Can't you stay quiet for a moment? You don't even know what kind of armor that is-

Yi-Han intervened, stopping his friends. Annoying the senior and missing out on valuable information would be a loss.

"Everyone, calm down and let's listen to the senior. What kind of creature is that armor?"

The walking armor was a summoned creature often used by the skull principal. Being non-living, it could roam the academy all the time, equipped with the ability to detect heat, making it a notorious summon for catching unlucky students!

But the harsher the academy, the more the students evolved to adapt. They had a few tricks up their sleeves: using fire magic to create a diversion, illusions that emitted heat to deceive it, or covering themselves thickly to prevent heat escape.

-The classroom here is under an illusion I cast. You can open the door and look out, but the armors won't notice. However, if you make noise, it's all for nothing. So please, everyone, keep quiet!-

'Ah, so that was the strange feeling.'

Yi-Han understood on his own.

When they had entered the classroom earlier, something had felt subtly off. It seemed unchanged at a glance, but it was an illusion crafted to emit just enough heat to be detected.

'This can be used in such a way too.'

Yi-Han mentally noted this, thinking it a valuable lesson. It would be helpful in his future wanderings around the academy.

"I didn't notice at all."

"Me neither."

-Would it be an illusion if you could notice it?-

The quill moved swiftly, leaving words that seemed to carry a hint of pride.

"So, senior, what were you doing here?"

-...-

"???"

-...I was heading to the kitchen.-

"That's great! We were going there too."

"But why were you heading to the kitchen, senior?"

The senior fell silent again. Yi-Han asked.

"Are you hungry?"

"Come on, Wardanaz. That can't be it."

"Right. A senior wouldn't be..."

-...Yes, that's it. I need a reagent hidden in the kitchen.-

The senior hastily made an excuse. The others exclaimed in admiration, but Yi-Han looked skeptical.

'It doesn't seem right.'

-The armors have passed. Let's move now.-

"Could I possibly learn the illusion magic you used to deceive the armors?" Yi-Han inquired. Surely, he would learn such magic in illusion class eventually, but Yi-Han needed it now. He couldn't exactly ask the walking armors to wait until he learned it.

The senior scoffed and started writing.

-I can tell you about it, but it's not a spell a freshman can learn right now.-

"Still, could you tell me the method..."

As Yi-Han persistently requested, the senior relented, albeit reluctantly, and explained.

<Farhaits Lesser Illusion>.

This was the magic used to deceive the walking armors. The chant "Heat, distort the air" summoned an illusion filled with heat.

Instead of altering the interior of the classroom, the senior had spread a curtain-like layer of appropriate heat. This was sufficient to evade the gaze of the walking armors, and summoning an illusion alongside required a considerable expenditure of mana.

There was no reason to waste mana unnecessarily.

'A freshman couldn't do it.'

The senior had readily shared this information, thinking it utterly impossible for a freshman. Lacking in both the skill to manipulate magic and the sufficient mana to wield it, how could a freshman cast this spell? It was quicker to teach them and let them quickly give up than to refuse outright.

"Freshmen, quickly, to the kitchen..."

"Heat, distort the air!"

As the incantation was uttered, an illusion enveloped Yi-Han and his party. To the senior watching from outside, it appeared as if Yi-Han and his group had vanished.

It was Yi-Han's first time casting this spell, and he wasn't sure if it had worked properly. So, he asked, "Did this work correctly?"

-...The aesthetic of the illusion seems a bit lacking... perhaps the colors are too faint-

The senior, almost unwittingly nitpicking, blushed upon realizing what he was doing.

What a disgraceful act!