The Demon Summoning Revelation
After a long, drawn-out explanation, Aria finally believed me when I said I wouldn't blow up the academy.
Well, "believed" might be a stretch—it was more like resignation etched on her face.
"R-Really...? You're not actually making some kind of bomb...?"
"No. Why the hell would I blow up the academy?"
"Even without a reason, it feels like you would..."
"..."
I had nothing to say to that.
It was a proper explanation, right?
I wanted to protest that it was unfair, but looking back on my usual behavior, I didn't have much ground to argue. To everyone else, I probably looked like a walking disaster.
With a deep sigh, I plopped down on the edge of Aria's bed.
"Anyway, it's not some bomb terror plot. Just hear me out."
"Y-Yeah... I'm listening for now."
Aria still hadn't dropped her suspicious glare.
She retreated to the far corner of the bed, hugging her knees to her chest as she eyed me warily.
"I mentioned it earlier, right? The list of materials I requested for the sewer repairs."
"Yes. Fifty high-purity A-grade magic stones, ten vials of mercury, mithril powder."
Aria recited it perfectly, word for word.
As expected from a scholarship student—her memory was sharp.
"Right. Do those materials really seem necessary for fixing a sewer to you?"
At my question, Aria stared into space, fidgeting with her slender fingers and mumbling to herself.
"Hmm... Actually, it's not completely unreasonable."
An unexpected answer.
"The underground sewers are full of moisture and pollutants, so regular magic circles corrode quickly."
"So that's why high-purity magic stones?"
"Yes. For a semi-permanent preservation spell, you need high output. One A-grade stone is way more efficient than a bunch of lower-grade ones."
"Efficiency, huh."
"Yeah. The upfront cost is high, but it saves on maintenance, so sometimes they splurge on expensive stones initially."
Aria's explanation was logical.
It matched the justification I'd written on the paperwork, too.
So was my suspicion off-base?
Frowning, I pressed further.
"So you're saying the request is more reasonable than it seemed?"
"No, not that..."
Aria tilted her head, trailing off.
"Something's... off with the ratios. If you're using A-grade stones, you wouldn't need that much mercury. And the amount of mithril powder... Hmm... Hold on."
She furrowed her brow, as if running complex equations in her head.
"It's hard to get precise numbers just imagining it. I'd need to cross-check mana efficiency and circuit layouts one by one..."
"How long would it take with pen and paper?"
"Well... With all the variables, at least three or four hours...?"
Aria glanced nervously at the clock, looking troubled.
She peeked at me cautiously before adding,
"Funny timing, but I still have homework left... Can we do this later?"
She's subtly trying to dodge the hassle.
Probably didn't want to get tangled up in some messy incident with me.
She'd picked up on the danger from all the talk of A-grade stones and such.
But I was firm.
"It's fine."
"Y-Yes? Fine how?"
"I've got time. I'll wait, so do it now."
"No, I meant I don't have time..."
Aria protested with a pout, but I ignored her and flopped right onto her bed.
A faint lavender scent wafted from the pillow.
The smell that always clung to Aria.
It was soothing, calming the mind.
"Whatever. I'm not getting up till you do it."
"W-What are you doing...!"
Aria freaked out.
"Why are you lying on my bed! You haven't even changed clothes!"
"We're roommates anyway, so what's the big deal? You can use mine."
"That's not the point!"
She grabbed my arm, trying to haul me up, but I didn't budge an inch.
"Do your homework later. This is more important right now."
"Ugh... You're so mean..."
Aria stomped her feet in frustration, grumbling.
But she lacked the strength to drag me off the bed—or the guts to flat-out refuse me.
With a deep sigh, she shuffled back to her desk.
"Fine... I'll do it, okay? I'll do it."
She rummaged out parchment and a quill.
'Knew you'd cave eventually.'
Acting all tsundere.
The scratch of quill on parchment filled the narrow room.
Aria started off grumbling, but once she gripped the quill, her demeanor shifted.
She'd pause now and then, chewing the quill tip as she puzzled over a snag, then dive back in, scribbling equations fluidly.
She's no ordinary girl.
I lay on my side, watching her back.
Her scholarly curiosity had apparently overridden her fear.
Reverse-engineering a circuit just from a material list.
Why hadn't a talent like this shone in the original story? I'd never even heard the name Aria, let alone seen her.
Probably her timid nature kept her from seizing opportunities.
Or...
Maybe she died.
The academy was riddled with incidents.
It wouldn't be weird for a commoner like her to get caught in one and vanish without a trace.
In this world, there wasn't much I could do for her in situations like this.
Just trust and wait.
Time crawled by.
The sky outside turned red, darkness settling over the room.
Sunset dyed Aria's hair, then faded into bluish gloom.
She was still deep in her calculations, without even lighting a lamp.
She's gonna ruin her eyes like that.
I got up and flicked on the room's magic lanterns.
"Huh...?"
The sudden light filled the room, and Aria finally looked up.
"It's already dark out."
She rubbed her eyes and peered out the window.
Too absorbed to notice the time passing.
"Yeah. Must be pretty complex. You still haven't finished."
"Almost done. Just verifying the math now..."
Aria buried her head back in the parchment.
Her desk was a mess of papers crammed with intricate magic circles and equations.
She solved all that alone?
I sat on the bed's edge, watching her.
And soon enough.
Click.
Aria set down her quill.
"Done?"
"It's definitely weird."
Tension laced her voice—different from before.
I stood and approached her.
"What's weird?"
Aria pointed to her calculated results.
"According to these numbers... These materials could make a space-warping transfer magic circle. One that summons something huge—a massive lifeform, like..."
She bit her lip, unable to finish.
But I knew what she meant.
"A demon, you mean?"
Her shoulders jerked at my words.
She stared at me, eyes wide with terror.
"...Right?"
Still suspects me, huh.
"No, I'm telling you."
"R-Right... Of course...?"
Aria sighed in relief, patting her chest.
But her expression stayed grim.
"But... someone is trying to make this."
"Yeah."
I gazed down at the magic circle sketch on the desk.
My hunch was right.
Someone was building a demon summoning array under the academy.
Using school funds, no less.
Bold bastards.
"Shouldn't... we report this?"
Aria asked anxiously.
"To a professor or... His Highness the Crown Prince...?"
"No evidence."
I shook my head.
"This is just your theoretical calculation. It won't hold up as proof."
"B-But... if we leave it like this..."
"Exactly."
I cut her off.
"That's why we need to check it out."
"Huh?"
"Go see for ourselves. Confirm if the circle's really there."
I shot to my feet.
"R-Right now?"
"Yep. Now."
"B-But it's dark outside... and underground sewers..."
"Perfect for sneaking in and out."
I grabbed my outer coat.
"W-Well, then..."
Seeing my resolve, she clasped her hands, looking solemn as she saw me off.
"Be careful... Come back safe, my lady."
I paused mid-shoe-lace and looked up at her.
"Come back safe?"
"Yes. If you're not back by morning, I'll report it right away."
Aria clenched her fist, full of determination.
I chuckled and stood.
Then strode over and snatched her wrist.
"What're you talking about."
"Huh?"
"You're coming too."
"......Huh?"
Aria's face drained to ashen in an instant.