Chapter 5
“Royal Summons and the Fate of Another World”
A bookmark in the story
That morning, Roselia Royal Academy of Magic was unusually quiet.
Students and teachers alike were whispering in hushed voices.
“Did you hear? The duke’s daughter and Professor Kai were summoned to the royal castle today…”
“Well of course. Two people from such different standings dating openly like that…”
“But wait, is that actually a ‘contract’ or is it really…?”
(…Well. At this point, even I’m not sure where the “act” ends and the real thing begins.)
With a sigh, Kai Cross straightened his robe and stepped into the carriage waiting at the academy gates.
Lutia was already seated inside, though her face looked tense.
“…You nervous?”
“Of course I am. We’ve been summoned by the royal family. If you mouth off at royalty and get arrested, don’t blame me.”
“Wait, you’re assuming from the start that I’m gonna do something wrong?”
◆◇◆
The pure-white palace rising over the royal capital Regnum—Alserio Royal Palace.
In its audience chamber, Kai and Lutia now stood before the throne.
A heavy, imposing atmosphere. Nobles and knights lined up on either side.
And at the far end, the king himself—Barnabas Alserio—wearing a crimson mantle, fixed them with a piercing gaze.
“You are… the one who came from another land, Kai Cross?”
“…Yes, I reckon that’s me. Probably.”
(“Probably”!? You can’t say “probably” here, idiot!)
Standing beside him with a severe expression was the king’s advisor and Great Sage—Hertz Gramroad.
His first words were cold.
“First, about the broken engagement. There is no mistake that this decision was made by His Highness himself?”
Prince Leon Adelheit, standing to the king’s right, nodded firmly.
“Yes. That was my own decision. Lady Lutia bears no responsibility whatsoever.”
Lutia’s eyes widened.
(…I didn’t think he’d admit it so plainly.)
But the matter didn’t end there.
“However, the problem lies in the fact that immediately after the annulment, you began seeing a commoner teacher.”
Hertz held up a document.
“It gives the impression you were secretly involved beforehand. This amounts to ‘unfaithfulness as a noble lady.’”
The air went taut.
In aristocratic society, “purity” was the key to preserving honor.
To be rumored with another man right after a royal betrothal—fatal.
“That ain’t true.”
Kai stepped forward and declared boldly.
“She and I only met after the prince announced the annulment. There wasn’t any ‘secret relationship’ before that.”
“Hmph. Your words are no proof.”
“Then how about I prove it?”
Kai’s eyes glimmered quietly.
“I’m a math teacher. Proving things with logic is my specialty.”
At that, Sage Hertz narrowed his eyes.
“…Then solve this.”
He produced the highest-level problem of the kingdom’s magical theory.
“Derive the stability constant of the threefold interference—time, space, and mind—in an ‘Infinite Overlaid Magic Circle.’”
Silence fell.
“No one has ever solved this problem. Unless you’re all talk…”
Kai took the paper and stared at it.
(This is… three-axis spatial-phase interference… oh, I see. If I convert it into vector coordinate transformations, I can tidy it up.)
He took up a pen. In a few minutes, his hand moved smoothly over the paper, and on the final line he neatly wrote “√2α×ΔΦ” before handing it back.
“Here’s the answer.”
Everyone in the hall gasped.
Hertz snatched the paper and read it intently—then his eyes flew wide open.
“Im… impossible…! This equation is the very essence of dimensional interference theory…!”
“You’d just left out one variable in the assumptions. Once you correct that, everything lines up.”
“H-how could you possibly…!”
“Think about it, it’s obvious.”
The king, the sage, the knights—and Lutia—all stared in shock.
She stood at his side, her mouth hanging open.
“Wha… what…? Since when were you this amazing…?”
“I told you, I’m a math teacher!”
“I heard you say that, but I didn’t think you’d casually solve the Great Sage’s problem…”
“Y’all are overhyping me… I’m just… okay maybe a little amazing, but really just an ordinary…”
As Kai flustered and babbled, Lutia suddenly burst out laughing.
“…Heh. What are you… You really are a strange person.”
At that moment—when Lutia showed a smile from the heart—
Prince Leon involuntarily held his breath.
(…That smile…)
No matter how many balls, how many banquets he’d attended—
He had never once seen Lutia smile like that.
Before he realized it, Leon’s right hand was pressed tightly against his chest.
(Why… why does my chest hurt…?)
The audience hall began to regain its composure.
“…Very well. We have witnessed your ability to solve what was deemed an ‘unsolvable problem’ of the kingdom.”
The king spoke gravely.
“Kai Cross. We hereby grant you the ‘Magical Special Qualification.’ In this kingdom, it is the official credential recognizing you as a ‘Magus Officer.’”
“Eh—eh, seriously?”
“This is separate from your role as a teacher. Your knowledge is a precious asset to the kingdom.”
(…This feels like there’s no going back now!)
◆◇◆
On the carriage ride back—
Lutia gazed out the window and murmured softly.
“…Thank you, Kai. Without you, I would have been finished.”
“I just didn’t wanna see you finished, that’s all. Besides, when you smile, it kinda makes me…”
“…Hm?”
“N-nothing. I didn’t say anything!”
“Heh… Even if you hide it, it’s all over your face.”
Outside the window, the lights of the royal capital glimmered—bringing the two of them just a little closer together.
