Beneath the Sunken Colosseum
The lights were out.
Black curtains hung thick over every window, sealing them shut. In that manufactured darkness, silhouettes of people shifted and stirred.
"All preparations are complete."
"So we finally set foot on Kizen's soil."
"I have waited for this day a long, long time."
Voices echoed in hushed secrecy around the room.
"The fate of our entire clan hangs upon this."
Then one figure in the center rose to their feet.
"Our opponents are Kizen itself. Leave no opening. Prepare for everything."
Simon thought that in all his time at Kizen, he had never seen so many outsiders roaming the school grounds.
The largest crowds he could recall were festival spectators and parents visiting on break days. But now, counting only the engineers, merchants, and outside officials who had come to prepare for the Dark Festival—not even counting the spectators yet—those old records had been left far behind.
And what would it be like once the Dark Festival truly began? His anticipation was already building.
Tap-tap! Clang-clang!
The sound of hammers rang busily across every corner of Roke Island. For stalls and smaller structures, the merchants hauled their own materials to the site and assembled them on the spot; larger buildings, like the stadiums, were transported whole via teleportation circles.
Of course, since this meant outside structures were arriving directly onto Roke Island, each and every one demanded meticulous inspection and investigation.
Simon, as a member of the Student Council representing the student body, had received notice to take part in the survey.
They left the Student Council room briefly in Dick and Camibarez's hands, and Simon set out for the site together with Mayrin, the Vice President.
"Is there anything strange about me?"
Mayrin asked this out of nowhere, turning to look back at Simon. With her sky-blue hair spilling down to her waist, she struck a slight pose, one hand adjusting her Student Council armband.
Her rippling sky-blue hair seemed to overflow with extra luster today, and her sapphire eyes waited round and wide for an answer.
Simon, who had been staring in a daze, nodded quickly.
"I don't see anything. You look the same as alw—"
The moment the words left him, Mayrin's eyes narrowed and a frosty expression surfaced.
Apparently that had not been the correct answer.
Red warning lights flashing in his head, Simon hurried to add, "—though also different! In a... what's the word? Effortlessly put-together way."
"Really?"
Fortunately, Mayrin let that one slide.
She seemed to be in excellent spirits today. Walking along with a light, springy step, she lifted her clipboard.
"As you know, Kizen leases the stadiums for the Dark Festival using teleportation magic. There are three in total today."
Kizen's scale truly surpassed imagination.
"We'll meet the stadium owners along with the committee members and check that there are no safety issues inside."
"Understood."
Simon gave his Student Council President's coat a light shrug and fell into step beside Mayrin.
It was a moment of leisure he hadn't felt in a long time. Setting work aside in his head and walking through the park breathing in the scent of grass, he felt his mind clearing.
"Hey, Simon?"
"Yeah?"
She twisted a lock of her sky-blue hair around her fingertip, then glanced shyly down at her own feet.
"Am I actually being helpful to the Student Council?"
Coming from the driving force who had been dragging the Student Council forward by its collar all this time, it was an almost absurd question. Slightly ironic, yes—but considering how violently Mayrin's emotions had been shaken recently, it made sense. Simon smiled.
"You're the best there is, Mayrin."
Mayrin flinched, and her face flushed crimson.
"Wh-who asked you to say that?! I was asking seriously—!"
"Even if any of the third-years had taken the Vice President's seat," Simon went on, his voice turning earnest, "none of them could have done what you've done."
He meant every word of it.
At that, Mayrin's eyes rolled this way and that, and the tips of her ears turned faintly pink.
"I—I don't know!"
She stalked off ahead of him in a huff, and Simon followed with a laugh.
Soon the two emerged onto the carriage road, where Mojo, the Student Council's direct servitor, was waiting by the carriage.
"President, Vice President. Your carriage awaits."
The Dark Festival's stage was all of Roke Island, and the stadiums stood far from the main campus, so they had decided to travel by carriage. Mojo drove it himself, and for the first time in a while, Simon and Mayrin relaxed and chatted comfortably through the whole ride.
Time flew by.
"We have arrived."
The moment they stepped down from the carriage, Simon spotted a familiar face among the adults gathered before the stadium.
A perfectly tailored suit, a restrained bob, and a cool, glacial expression.
It was Jane—Vice Principal of Kizen and Chairwoman of the Dark Festival Committee.
"Professor Jane!"
Mayrin ran over, beaming with delight, and Simon followed with a polite bow of his head.
"You've arrived, President. Vice President."
Just as expected, Jane addressed her students directly by their titles. Simon chuckled inwardly, wondering if anyone in the world drew a cleaner line between public duty and private feeling.
Around her stood men with long, flowing mustaches—committee members, apparently, deep in conversation.
And facing them stood a group of men in somewhat shabby work clothes.
"Allow me to introduce them."
Jane introduced Simon and Mayrin to the group. They were the holders of this stadium's ownership—a clan known as the Valkeze. They seemed to be a family with quite a long and storied history.
Hmm.
Simon found them distinctly untrustworthy. The way they kept darting nervous glances around, twitching at every little thing, made them look like men with a guilty conscience.
Having finished the introductions, Simon finally let his gaze drift to the stadium itself.
Ancient ruins, perhaps. It was unmistakably a colosseum, and one glance told him it was tremendously old. Built of stone, its surface felt rough and uneven under the palm; the walls were riddled with holes like windows, with grass and even small trees growing out of them here and there.
He doubted every stadium would be like this. There were surely plenty of cleaner, more modern venues—so the reason for leasing this particular one was probably something related to the exams.
Not that he could ask Jane about it.
"Now, let us proceed inside."
As they walked, Jane fired sharp questions at the Valkeze clan who owned the stadium, and each time, the Valkeze side answered with sweat streaming down their faces.
If they had assumed Kizen's sheer scale meant minor issues would be waved through breezily, they were sorely mistaken. Under Jane's relentless pressure—pointing out everything from the building's state of preservation down to the cost of repairs—the Valkeze clan ultimately agreed to cover the renovation expenses out of their own pockets.
Jane's display left a deep impression on Mayrin, whose eyes were shining as she copied every single one of Jane's questions into her notebook, omitting nothing.
Soon they entered the stadium.
"Whoa."
Mayrin's mouth fell open.
"This place used to be a swimming pool?"
Splash-shhh—!
Water poured from the statue at the center of the arena like a waterfall. The floor of the stadium was filled to the brim with blue water, and every seat in the stands looked down over the whole spectacle.
Wow.
Simon was impressed despite himself. A magnificently ancient, classical arena-cum-pool.
It was a stunning place. Nobles would fight tooth and nail just for the chance to sit in those stands for even a moment.
"Then, we will begin the inspection."
Jane turned to the committee members, Simon, and Mayrin.
"We will sweep the entire stadium to identify anything that could obstruct or endanger the students during their matches. I ask that you check even the submerged areas with particular care."
Simon blinked at that.
"And... us?"
He and Mayrin were in their uniforms. Jane and the committee members could no doubt make their way around without getting wet through some application of dark magic—but the two of them hadn't yet learned that level of spellcraft.
Jane rested a hand on her hip, her expression utterly flat.
"The Student Council is not exempt. Change into your swimsuits and begin the inspection."
"Whaaat?!"
Mayrin was aghast.
"We didn't even bring swimsuits!"
"Mojo."
Jane turned her head and called the name, and both students' eyes swung around after her.
There stood Mojo, waiting with the world's most unbothered expression, both of their swimsuits held up in his hands.
"AAAGH! Why is MY swimsuit THERE?!"
Face burning scarlet, Mayrin flailed her arms wildly as she sprinted toward him.
Simon came back out in his swim trunks.
Jane and the committee members had apparently already left to begin their inspection.
And then—
"..."
Mayrin was crouched down, arms wrapped around herself, face blazing red.
She had been like that, without a single word, ever since changing into her swimsuit. Simon snorted a laugh.
"You waiting here, then?"
"I-I'm coming!"
Mayrin squawked, then buried her burning face even deeper.
"I'm... I'm the Vice President of Kizen, after all."
"...Why are you making such a fuss now? We've been to the beach in swimsuits together before."
Back in their first year, they'd all practiced dark magic together on the beach to prepare for the maritime portion of the BMAT.
And right now there were barely any people around to see, and the coverage of this swimsuit was far more modest than the one she'd worn back then.
"That was a BEACH!"
Mayrin snapped, her flushed face flaring.
"And back then everyone was equally undressed—it's just the two of us in swimsuits now!"
"...Haha."
Simon couldn't see the difference, but there was no arguing with someone that embarrassed. He shot a long, pointed glare at the Valkeze clan members peeking furtively from the distance, then stepped forward.
Better to just get it over with.
"I'll go in first, then."
"Huh, huh?"
Pinching his nose shut, Simon leapt boldly into the water-filled arena.
SPLASH!
A great column of water shot skyward, and Simon's body plunged in with a gurgle of bubbles.
Ooh.
He'd been a little worried since the water was such an intense blue, but the quality actually looked better than he expected. Forgetting his mission entirely for a moment, Simon splashed around with glee.
It felt as though all the fatigue and stress he'd been carrying was flying away at once.
"Mayrin! Come on in! It's so cool, it's amazing!"
Simon popped his head above the surface, grinning wide. Mayrin, who had been hovering awkwardly at the edge, squeezed her eyes shut and rose to her feet.
"Ugh, fine, whateverrr!"
And with that, she launched into a flawless diving pose.
SPLASH!
Mayrin entered the water safely. The coolness caught her off guard—her eyes went wide as saucers—but within moments she'd forgotten her embarrassment entirely, gliding gracefully through the water as she circled the area.
After a short while of the two of them slicing refreshingly through the water, Mayrin remembered the mission first and pointed ahead.
The two cast Breath Magic on themselves and made a full circuit of the pool, inspecting the stadium's condition.
The ancient arena looked charmingly antique, but its age showed—jagged, sharp protrusions lurked in quite a few spots.
Any student racing through here could gash themselves badly or take a serious injury, so Simon checked every single one without fail.
Swish, swish—
Then, from a little deeper down, Mayrin gave the tip of Simon's foot a light tug.
!
Her sky-blue hair billowed and scattered beautifully through the water—she looked, in a word, like a mermaid straight out of a fairy tale.
While Simon stood there dazed, she flailed her arms in an angry gesture and pointed downward. The floor had peeled away, exposing something reddish, as though corroded or oxidized. The water was deep enough that it posed no immediate danger, but they agreed to report it to the committee as well.
Having finished the first survey, the two rose back above the arena.
"Pwahah!"
"Hoo!"
Simon climbed out first and reached back to pull Mayrin up. The moment she was out, water dripping from her, she launched into an impassioned tirade.
"Seriously, isn't this place a total disaster? The preservation state is an absolute mess! Especially underwater—there's so much that needs fixing."
"Yeah. Let's organize it and report to Professor Jane."
Mayrin pulled a checklist out of her subspace pocket, rewrote the items they'd confirmed from outside the water, and then plunged straight back in.
Considering the time they had left, this would be their final dive.
Bubble-bubble-bubble!
The place was so deep and vast that there was plenty left they wanted to explore. Mayrin, thoroughly enjoying herself now, powered ahead.
This is work, sure, but it's kind of fun.
Swimming alone together in an empty arena while everyone else was buried in their studies—it felt like a little act of rebellion, a strangely delightful experience.
[Boy.]
Just then, the Pier-shard he'd tucked into his swimsuit pocket spoke up.
What is it, Pier?
[I sense a strange energy nearby!]
A strange energy? Pier was not the kind of undead to spout nonsense, so Simon stopped moving at once.
Where? I'll head over right now.
[A little deeper down, here.]
Simon dove without hesitation, cutting through the currents straight toward the bottom, scanning his surroundings as he went.
[Now to the right!]
[You must pass that pillar over there!]
Following Pier's guidance as he kept moving, Simon soon found himself at what appeared to be a water channel running through the stadium.
Back when this arena had stood in its original location, it had drawn on a nearby river—which meant this one section stayed submerged three hundred and sixty-five days a year.
At a glance, it was a stretch anyone would simply swim past without a second thought. But on Pier's instruction, Simon peeled away the moss clinging to the wall.
!
There, set into the stadium wall, was a hole—one that instantly brought an undersea cavern to mind. If he'd just swum by, he would have missed it without question.
Simon narrowed his eyes and peered into the opening.
A passage bored straight upward. Where does it lead?
Just then Mayrin, apparently worried about him, came swimming over. Simon immediately signaled that he'd found a hole, and the two slipped inside together.
Then they swam up the passage, higher and higher.
"Pwah!"
"Haah!"
Before long, both of them surfaced and lifted their heads out of the water.
Somewhere along the way, their surroundings had turned into a cave.
"What is this place?!"
Mayrin gasped. Simon too looked around with wide, startled eyes.
"Underground... I think. Is a structure like this even possible inside the stadium?"
A hidden natural cave, secreted away within the arena. The two exchanged a look and nodded.
As Kizen's Student Council, they could hardly let this slide. Bracing for any eventuality, they raised their Jet-Black and moved slowly forward.
"!!"
Then Mayrin, who had been walking calmly at his side, went white as a sheet and clapped both hands over her mouth.
"What's wrong?"
"S-Simon! Over there...!"
Scattered across the floor of the cave, in utter disarray, were bones.
Human bones.