Offense and Defense Switch
Earth-attribute mana arrows slammed into the barrier.
BOOM!
But the barrier showed no damage whatsoever.
"…."
While the students stared at the scene in a daze.
"Student Hwang In-su has one chance left."
Park Ha-jun's flat voice echoed through the room, like that of an exam proctor.
"…!"
Those words snapped the students back to reality.
Time limit: 30 minutes. Chances: two only.
Yet the barrier held firm even against a 3rd circle master mage's meticulously crafted mana arrow.
The message was clear.
If they didn't follow Park Ha-jun's intended solution, they could fail the test….
Of course, some students weren't thrilled about the situation itself.
They'd already passed the official test—why another exam?
But there was no time to voice complaints.
Tick. Tock.
Time kept slipping away.
With their social reputations on the line, failing would be a major blow.
In the end, the students had no choice but to focus on the papers Kim A-hyun had handed out.
Even Hwang In-su—one of the top three in this classroom—had failed, hadn't he?
No reason to attempt something reckless….
Except for one mage who was confident he could cheat his way through.
Jeong Hyun-seok, brimming with self-assurance, simply peered at the barrier with interest.
He was reverse-engineering the formula embedded in it.
It's implemented in a peculiar way.
He couldn't fully deduce the formula due to its unfamiliarity, but….
That strangeness reminded him of someone.
asd123. The mysterious scroll maker who packs unique phenomena into single sheets.
Of course, Kang Eun-ho's barrier didn't even come close to asd123's interception barrier.
But the fact that it deviated from the system's cookie-cutter formulas sparked great interest.
Kang Eun-ho, was it? I heard he was an A-rank mage struggling at 1st circle.
Rumors said he'd unlocked 2nd circle just two months ago.
But this went beyond mere circle unlocking, didn't it?
What on earth had happened in those two months?
And why was a proud mage serving as a math professor's TA?
Just who the hell is that professor?
Questions piled up, but all that remained was intense curiosity about the professor and Mathematical Circuitry.
I wonder what his goal is. What changes will come after finishing this course….
So Jeong Hyun-seok decided to strictly follow Professor Park Ha-jun's intent.
At least it didn't seem like a negative change.
……Meanwhile, Park Ha-jun stood quietly at the lectern, watching the students.
Hwang In-su, right? Good timing.
The unannounced test wasn't the best method. It risked major backlash.
But thanks to Hwang In-su drawing attention, it had gone smoothly.
Though the magic-blocked Hwang In-su looked a bit panicked….
He was at least scribbling furiously, alternating glances between the formula and barrier.
At least it proved his second-place finish in the last test wasn't pure cheating.
Park Ha-jun smirked at him, then shifted his gaze.
To a student gnawing their nails.
Can't solve it at all, huh.
Actually, when grading the answer sheets, there had been identical wrong answers. Very wrong ones.
Probably shared via mail between students, since the exam problems were the same back then.
But this test was different.
The barriers manifested before the twenty students each had different forms.
Different forms meant different weak point locations.
In other words, you couldn't solve this together via mail, which couldn't transmit photos.
Everyone makes mistakes….
Park Ha-jun planned to let it slide with a gentle reprimand if their skills were up to par.
But if they couldn't solve this—nearly identical to problem 1 from before—their skills were lacking….
"20 minutes remaining."
Expulsion.
As Park Ha-jun eyed the two with a blank expression.
Pop!
The first passer appeared: Shin Ye-ji.
Having beaten Jeong Hyun-seok to it, she clenched her trembling fist.
"Congratulations. You're through."
The other students let out silent gasps.
Park Ha-jun handed her the booklet and a scroll, continuing.
"Lecture materials, class notes, and a small gift. You may go home now."
The scroll was Kim A-hyun's work, of course—Park Ha-jun's would be marked asd123.
Shin Ye-ji bowed happily, accepting them.
"That was really fun to solve, Professor!"
Park Ha-jun smiled back and waited for the next.
Three minutes later, Jeong Hyun-seok and Hwang In-su broke their barriers in turn.
"A novel problem."
Jeong Hyun-seok left a brief impression.
"…."
Hwang In-su, pale from his single remaining chance, just nodded meekly.
Afterward.
"10 minutes left."
No sooner had he spoken than barriers shattered here and there.
Park Ha-jun distributed materials and scrolls to them.
One of them was a suspected cheater.
Not solved together, but one-sidedly shared, maybe?
This one probably received it; the nail-biter over there was the sharer.
After a moment's thought, Park Ha-jun asked before handing over the materials.
"…Any last words?"
Silence fell. Park Ha-jun tapped the lectern with his finger.
The man swallowed hard.
"There should be."
Biting his lower lip—
"…Sorry! I shared answers with my friend because I wanted to take the class together."
Nothing special. Park Ha-jun nodded and checked the time: 3 minutes left.
"Everyone else, you're free to go."
A tense atmosphere hung. They glanced around and left.
Only two students remained: the sharer and receiver.
The one who hadn't passed yet fidgeted anxiously.
"It's not over. Focus on the test."
"…Sorry. I, I can't solve it."
Park Ha-jun checked the clock: 1 minute left.
He nodded and approached. The student flinched.
But.
"How far did you get?"
At Park Ha-jun's words, the student looked dazed.
"…Pardon?"
He gaped at Park Ha-jun.
But Park Ha-jun spoke as if unconcerned about the cheating.
"This is just about finding the circuit's essence. As long as you preserve that, the form doesn't matter, no matter how it changes…."
The explanation sank in perfectly. Warmth melted his anxiety.
"…Yes."
"Ah… Extending the barrier while keeping this formula part intact makes the same shape."
"Oh… So the weak point is here…."
Whoosh. Pop!
Under Park Ha-jun's guidance, he shattered the barrier. A storm of emotion hit.
"Whoa… So that's the problem…."
Park Ha-jun smiled warmly.
"Solving it yourself isn't so bad, right?"
"Yes…."
Park Ha-jun watched him a moment, then spoke at the right timing.
"No need to apologize to me… I just regret you missed the joy of struggling and realizing on your own."
Though it had also stolen another’s spot.
No need to lecture on that. He was a professor, not their homeroom teacher….
Finished, Park Ha-jun handed over only the class materials. These were special, annotated in detail.
"If you want to attend, come back next semester anytime."
Meaning: failed this time.
The student stared at the materials with a complicated expression, then spoke.
"Yes… Sorry."
Park Ha-jun nodded and asked the sharer.
"What will you do? Join your friend next semester?"
"…Yes, we'll do that. Truly sorry. We didn't mean to disrespect you, Professor."
Park Ha-jun smiled.
"No problem. I look forward to seeing you improved next time."
……
In that warm atmosphere, Park Ha-jun left the classroom with his TAs.
19 passed the surprise test.
Final enrollment: 18. The two spots would be filled with waitlisters.
Smooth days followed the surprise test.
Analyzing the 4th circle attack spell—Lava Eruption—or pinpointing Lab 2 and the Mines' location.
Park Ha-jun expected perfect Lava Eruption scrolls first.
But progress came first on locating the Mines.
Park Ha-jun arrived at Lab 2 after a text from the researchers.
One showed the monitor, reporting results.
"Based on the hypothesis of an unknown continuous manifold between the two discontinuous spacetimes A and B, we modeled using Riemann curvature values as variables."
In simpler terms: assuming continuous dimensions between Earth and gates.
They'd mathematically modeled those in-between dimensions.
Now, properly wielding darkness and space based on this could get them into the Mines' hideout.
Of course, only if the continuous manifold hypothesis held.
If not, things could get tricky.
But no way to prove it now.
Might be possible with special equipment.
But that wasn't Park Ha-jun's concern.
As always, he'd make the best scrolls and send them. The Association wasn't incompetent.
Sorting his thoughts, Park Ha-jun thanked the researchers.
"Good work, everyone…."
"No, it was a fascinating project. We really enjoyed this research."
True. Pure academic research was inherently thrilling.
Just lacked funding and conditions, so people avoided it.
"Haha. Glad to hear. Don't overdo it—rest well for a while."
As Park Ha-jun bowed and turned to leave.
"…Professor?"
One researcher stopped him.
"…More?"
"Hm?"
"Projects… give us more…."
"…."
I see….
Park Ha-jun realized.
Pure research without money worries was enjoyable.
But well-funded pure research was addictive….
So he promptly assigned Lab 2 a new project.
Then emailed the Association.
The Mines, hell-bent on plunging Earth into peril.
We won't just take it lying down.
Now, offense and defense switch.