Inside the tower, a different world awaited.
The moment I stepped in, the air shifted—not just from the temperature change.
Torches illuminated the space, but what was strange was that some device had been set up, making them flicker on and off by themselves. The walls were rough and damp like a cave, so it hardly felt like we were inside a building at all. What puzzled me most was the number of doors. Identical ones stretched out in both directions, spaced at precise intervals.
Even before I noticed any of that, a sign had already caught my eye.
Welcome to the Rainbow Floor!
※First rule※
Conversations are prohibited on this floor.
There will be a penalty for the violation.
What a load of crap about leaving a good impression. Cancel that. Cancel it again. And once more for good measure.
This person was far more insidious than Assad or Lise thanks to the stark contrast between his inner nature and outward appearance. I knew the tendencies of mages well enough, so I kept my mouth shut.
It was odd. I was sure that the best of the best had gathered here, yet it seemed as if idiocy followed some strange law of conservation.
"What's gonna happen if I talk?" some idiot challenged.
A flash of light followed, and the hero disciple who had spoken vanished. The remaining hero disciples let out silent screams. Some quickly slapped a hand over their mouths, stifling their half-formed cries.
Where did the missing person go?
I don't think he'll die.
Curiosity gnawed at me. Using the cover of the subtle darkness, I activated my divine beast transformation. As the energy concentrated in my eyes, my range of detection expanded, reaching beyond the first floor to the area outside the tower.
He is outside.
He'd been forcibly expelled.
I saw him, pale and kicking at the door, but there were no signs of the door opening. Inside, I couldn't even feel his presence. It was as if we were completely cut off from him.
It was unsettling. The distance wasn't great, yet he had been expelled without realizing it.
Could I resist that?
It was hard to say. I'd need to experience the force firsthand to understand its power, but testing it would be risky.
By the way, what exactly counts as "conversation"?
For instance, did writing on a piece of paper count? What about a sound transmission? Or secondary communication through spirits or summons? What about a blessing that allowed telepathic messaging?
Just then, someone cleared their throat and gave it a try. It was Charis. He'd done it deliberately, but unlike the fool before him, he wasn't kicked out.
Still, where did this lunatic find the nerve?
"I-I'm not kicked out...?" He even braved to cautiously speak!
The hero disciples stared at him in surprise. Nothing changed this time either.
Wait. Does this count as talking to yourself?
The hero disciples realized something and cleared their throats awkwardly.
"W-what a dog-like place..."
"H-hm. I need to figure out how to go up."
"It is suspicious that there are too many doors!"
"So, which one are you all going to—Ah!" The speaker, still mid-sentence, vanished in a burst of light.
Idiot. I gave this person a pitying glance, then looked forward again. The definition of conversation is unexpectedly loose.
I activated Serpent Eyes and studied the door. Even with this power, which allowed me to see outside the tower, I couldn't discern what lay beyond it. Still, I did learn one thing: the torches inside weren't real. They were torch-shaped magic tools.
This discovery came courtesy of Serpent Eyes. Using this ability, I could also gauge the temperature of objects. The torches flickered on and off at regular intervals, and their temperature was low enough to touch with bare hands.
Why design them this way?
Whatever the reason, the oppressive tension kept everyone frozen in place. Finally, Butterfly was the first to stride forward.
Could he have already solved the puzzle? I wondered.
As all eyes turned to him, Butterfly gave a sly smirk and boldly yanked open the nearest door. What happened next left us stunned.
Another door in the wall creaked open.
"What...?"
To our disbelief, Butterfly emerged from it.
"W-what is this..."
The hero disciples, hesitant to speak aloud, couldn't help but let their confusion slip into words.
Even seeing it with our own eyes, it was hard to believe. From one door, we saw Butterfly's back; from another, we saw him from the front as he opened it.
"Uhh..."
Butterfly was likely just as flustered as the hero disciples watching him. Given his awkward demeanor, he hadn't solved the puzzle. He had simply opened the door without thinking.
Either way, once Butterfly made his move, the other hero disciples followed suit, opening doors at random and reappearing through others.
Naturally, this led to collisions.
Thump!
" Ack! "
"What?"
Two people—one entering, the other exiting—slammed into each other. Unable to speak, they expressed their frustration with exaggerated faces and frantic gestures.
I observed the situation from a distance and noticed something off. Hasn't the number of people decreased a bit?
It wasn't obvious, but some who had opened doors at random had disappeared. Among them were Pam and Charis.
Had they solved the puzzle?
I wasn't sure about Pam, but I doubted Charis had figured it out faster than me.
At that moment, someone brushed past me. Their hair wasn't white, but a flutter of silver. It was Seren. She walked proudly through the confused hero disciples and opened a door.
I widened my vision to take in the full door, but Seren was already gone.
She moved to the next level.
Her demeanor and attitude set her apart from the other hero disciples. While the others seemed oblivious, Seren appeared to either have solved the puzzle or known the answer from the start. In any case, maintaining the divine beast transformation felt draining, so I closed my eyes. When I opened them again, my normal vision had returned.
Just then, I had a strange feeling.
Hmm? The color of the door seems to have changed slightly.
Though the surroundings were dark and not easily visible, I could now see an orange hue. It wasn't an illusion. As the torches flickered on and off, the color changed again, this time to yellow. I noticed that the door's color changed with the torches' flickers.
Wait a minute.
I recalled the color of the door Seren had just entered. It was red. In addition, the name of this floor was the Rainbow Floor.
Hmm... I think I'm starting to understand.
I moved quickly when the door's color returned to red.
***
As soon as Seren opened the door, a new room greeted her. Like the last, the walls were lined with ten doors. But this time, no other hero disciples were present. The sudden silence was unsettling, yet Seren remained unafraid.
She noticed the door colors still changed slightly with the torches' flickers.
Orange. It's now.
Seren pushed the door open and stepped inside, only to face another room. She waited for the door to turn yellow before opening it.
This was the mystery of the Rainbow Floor. As the torches flickered, the doors cycled through a spectrum of colors. One had to move through the seven colors in the right order, timing it perfectly, and the puzzle would be solved.
It was a simple pattern, but the tower's dim lighting made the color changes so faint and brief that most would miss them entirely.
Of course, this puzzle was just the beginning.
Seren closed the purple door with a sigh. Before her, a staircase materialized, its base marked by a sign that read, Infinite Stairs.
This is where it truly begins.
To be honest, Seren had no idea how long it would take her to climb these stairs, but failure wasn't an option. If she didn't succeed here, she'd be kicked out of the academy. Seren couldn't allow that, so she slowly climbed the stairs.
***
Hector was climbing the stairs.
The rainbow puzzle didn't pose much of a challenge for him. He'd cracked it in just fifteen minutes. Unbeknownst to him, that made him the second fastest among the thirty hero disciples. Since Seren had come in first, solving it just after her was essentially the same as being the fastest.
The staircase before him, known grandly as the Infinite Stairs, had appeared immediately after the puzzle. He'd been climbing it for an hour without pause.
It is strange, he thought.
With Hector's physique, he should've reached the top long ago. Realistically, he could've gone up and down two or three times by now. Yet, the spiral staircase showed no sign of ending.
It's magic, he concluded, though he didn't understand its exact effect on the stairs. Could it really be infinite? Or was there another path hidden from view?
Hector considered it a puzzle and tried every method he could think of. He sprinted up the stairs at full speed and swung his sword at the wall next to him. His final attempt was to descend, but that proved equally futile.
He had assumed he'd climbed tens of thousands of steps, but when he tried to go down, the bottom came into view in no time.
" Tch...! " Hector's competitive spirit flared. He gave up on retreat and resumed climbing with renewed determination.
An hour later, his body was drenched in sweat. He had exhausted his mana long ago.
No. It feels like I ran out of mana faster than usual.
Was this also the power of this staircase?
He sucked in a deep breath. His thighs and calves burned, swollen with heat, on the verge of giving out.
He longed to sit down, but he lifted his head and muttered, "I'm not quitting here."
***
" Kuhahaha! " Alderson let out such a wicked laugh that no person would associate with an educator. He looked like a child who had just gotten his hands on the most coveted toy in the world.
"This is it! The first in Alderon's masterpiece series—the Mana-Eating Stairs!"
The Mana-Eating Stairs were a device of Alderson's own design. It drew mana directly from the climber, using it as fuel to generate an endless staircase. In other words, once the climber was overwhelmed by the seemingly infinite steps and used mana, the number of stairs would multiply.
Of course, the stairs were already incredibly long without any mana expenditure. Climbing at least 50,000 steps was required. The true challenge of clearing the first floor lay in reaching the top without using mana.
No wonder they resent the Tower of Training so much.
The spectating professors looked on with pity as the hero disciples struggled up the tower. Many had already collapsed or given up.
Even so, a few stood out.
"Charon Woodjack definitely stands out among all the others. His climbing speed is exceptional, and his base stamina far surpasses that of a typical hero disciple."
"In terms of raw speed, Butterfly Goodspring's the fastest. He's already halfway up."
"Hector Badniker's tenacity is remarkable. His stamina's shot, but he shows no sign of stopping."
Alderson stroked his beard in satisfaction. He had poured immense effort into designing this tower, and seeing certain talents rise to the challenge made it all worthwhile.
"The quality of this year's transfer students is incredible! By the way, what was the number one record for the Rainbow Floor among the enrolled students?"
"It was six hours, thirteen minutes, and twenty-seven seconds."
Alderson glanced at the time. Only three hours had passed since the test began.
" Oh-ho... " Alderson looked at the screen with a gleeful expression. "Then we might see a new record today."
This was what fueled him—those expressions, that pain, the desperation, the anguish etched on the young faces. It always energized Alderson. A dark chuckle escaped him, and the kindly elderly man who had greeted them at the tower entrance disappeared entirely.
The other professors wore stiff expressions, pretending not to see the academy's dean.
It wasn't that Alderson was a bad man. Objectively, he was a good dean and a man worthy of respect. Why else would the imperial family have acknowledged him and bestowed the Seven-Colored title upon him?
Still, all mages had a screw missing somewhere.
The sad truth was that Alderson was relatively decent by mage standards. He didn't mean anything malicious by all this.
At that moment, Morland, ever meticulous, scanned every corner of the screen. Suddenly, he gasped and blinked slowly a few times.
Once he realized it wasn't an illusion, Morland called out, "Excuse me... Dean Alderson?"
Alderson's voice brightened. " Oh! Professor Morland. Did you finally find the cookies? The tea's cooled a bit, but I can heat it up quickly with magic."
"N-no. That isn't it..." Professor Morland's voice sounded dazed. "Someone has almost finished the Infinite Stairs...?"
Alderson's smile cracked.