"Ah. This is the boss room."
We had reached the boss room on the 50th floor.
I’m sure that makes perfect sense—or at least, as much sense as it ever does—but we had actually reached the boss room.
I knew exactly how we’d gotten here. Roxanne had led us. I had caught a glimpse of something even more terrifying than usual.
"O-Oh."
"Hmm. As I thought, it took a little time to find the boss room. Conquering a labyrinth is hard work."
Roxanne remarked this casually, looking as though she hadn't found it difficult at all. In reality, it hadn't been hard for her. Not for Roxanne.
As for me, it had been... well, it was what it was. I wouldn't go so far as to call it "hard," but it certainly wasn't easy. Even in normal battles, it was taking longer to annihilate the monsters. I lived in constant fear that another swarm might wander in and join the fray while we were busy.
Apparently, one of the most common ways explorers die in the labyrinth is being swamped by a second group of monsters while they’re still struggling to finish off the first. We weren't immune to that possibility. Of course, before that happened, Roxanne would likely smell them and bark out a warning.
However, in Roxanne's case, I harbored a dark suspicion that she might joyfully dive into a spot where multiple swarms were gathered specifically because they were there. That was just the kind of thing she’d do. Daily mindfulness was important.
If you asked whether a boss battle was safer because there were no monster intrusions, I still had my doubts. Boss battles relied heavily on Miria's petrification. If that ever stopped working, I didn't know what we'd do. Anxiety was a persistent thing.
There’s an old story about a man from the state of Qi who lived in constant dread that the sky might fall on his head. Groundless fears like that never truly run dry in this world. I knew petrification probably wouldn't just stop working out of nowhere, but there was always the chance that, through sheer bad luck, we wouldn't be able to trigger it before the end.
And since the 50th floor was a major milestone, it was possible that something might change. Maybe. Perhaps. In a million-to-one chance. Or a billion-to-one. In the absolute worst-case scenario.
I wasn't even sure if the 50th floor actually counted as a "milestone." I wondered if the labyrinth even thought in base ten. Since floors seemed to be grouped in sets of eleven, if the labyrinth used base-eleven logic, the 56th floor would actually be the more dangerous milestone.
Still, since a labyrinth supposedly emerged on the surface once it grew to the 50th floor, I suppose you could call it a milestone of sorts. Even with humans, being eighteen might be a "milestone," but nothing physically changes the moment you turn eighteen. That’s just a legal distinction. In a country where you become an adult at twenty, twenty is the milestone. In ancient Japan, some people had their coming-of-age ceremonies as early as five.
A labyrinth was its own thing, and maybe the 50th floor meant something. There might be new dangers. Unexpected variables. The possibility wasn't zero.
Therefore, Roxanne—just because Sherry finished her explanation, don't charge into the boss room so joyfully. Have more of a sense of crisis. Imagine the worst-case scenario and never neglect your preparation. Stay calm so you can handle any difficulty. Quiet your heart. Prepare yourself to respond to any disaster.
Or so I thought.
But as it turned out, the 50th-floor boss was no match for Miria either. As expected of Miria. We were still fine. It was a relief.
Then again, even in a boss battle, half the enemies were just small fry that appeared on the normal floors. It was only natural for Miria to petrify them. Even if the boss itself became immune to petrification, as long as there were only two of them, Roxanne and Vesta could stand at the front and manage them. In a boss room, at least we didn't have to worry about extra swarms interrupting.
That said, the limits were approaching. Between the 49th and 50th floors, the monsters had grown significantly stronger, while we hadn't seen an equivalent leap in power. The ceiling was getting closer. It was a deep-seated worry.
"Vesta, were you all right against the 50th-floor boss?"
"Yes. I believe I'm fine."
"If you think it seems even a little dangerous, don't hesitate to say so."
"I understand."
She really did seem fine. If Vesta said so, then the boss battles on the 50th floor weren't an issue. As for the other person confronting the boss head-on... I already knew she was fine. I didn't even need to ask. In fact, it was better if I didn't. She’d probably just say the 50th-floor boss was "nothing at all," or something even more terrifying.
I shivered.
"Since we’ve cleared the boss room on the 50th floor, that means it’s time for 'that,' isn't it?"
Instead of Roxanne, Rutina was the one to jump in. By "that," she meant the Duke's offer. She probably didn't even want to say his name, given the history with her father.
"That, huh? Well, we do have to go."
"He's going to introduce a labyrinth that can be subjugated at the 50th floor, right?"
Sherry, please read the room. "That" was a perfectly fine way to refer to it.
"That's right."
"I haven't heard of anything changing just because the final floor is fifty. Is there really a need to go through the trouble of an introduction?" Sherry asked.
"You've got a point."
As expected, Sherry shared my doubts. If there was no difference, we could just keep practicing on the 50th floor of Quratar.
"It is a matter of noble dignity," Rutina said, dismissing the question. She was always particularly sharp when it came to Duke Harz’s motivations.
"I see. He can't act like a big shot without at least providing an introduction."
"Exactly. And no matter what favors we accept now, I have no intention of letting him act like he owns us."
She was strict. Though, to be honest, the fact that he’d given Rutina to me was the single greatest favor I’d ever received from him. From Rutina’s perspective, however, the "benefit" was practically non-existent.
"In that case, should we turn him down so he doesn't get a big head?"
"No. We should accept. There’s no reason not to take what we can get. Besides, if he thinks he can act superior with just this much, it’s laughable."
"I see."
So we were going to accept the Duke’s introduction. I felt better knowing that accepting wouldn't automatically mean Rutina felt indebted to him. But I wondered what "acting like a big shot" would look like for him. Would he go around saying, "I'm the one who trained Michio"?
Honestly, I didn't mind if he did. I could see myself playing along: "My ability to subjugate the labyrinth is entirely thanks to His Excellency Duke Harz. The secret to my strength? His Excellency's peerless guidance, of course! I have no special skills, no unique jobs, no legendary weapons—nothing. I am merely the humble result of following His Excellency’s lead. Surely it is the Duke himself who holds the secret to growth."
Yeah. That would work. Let’s go with that.
The next morning, I went to Bode to report to Duke Harz. Strike while the iron is hot. Or, as they say, "I have heard of foolish haste in war, but a clever delay is never seen."
"He is in the executive office with the Commander."
In Bode, I was told to head to the back on my own as usual. I wondered if that, too, counted as "haste."
"Enter."
When I knocked on the office door, Knight Commander Gosler called out. Having Gosler there was a relief. It definitely wouldn't be "foolish haste" with him around.
"It's Michio."
"Ah, Michio-dono. Please, have a seat."
When I entered, Duke Harz welcomed me with a broad smile. He must have been in the middle of some actual work and was clearly happy for an excuse to slack off. But that work wasn't going to disappear, you know. Then again, if he was wrestling with a problem that made him want to pull his hair out, maybe I was a welcome distraction.
Though, I doubted the Duke actually did the hair-pulling himself. He probably just pushed the hard stuff onto Gosler.
"We were just discussing the reorganization of the Knight Order for the Yetzera conquest," Gosler explained.
I didn't quite follow the details, but they were probably moving people around. It sounded like a massive headache. No doubt the Duke had dumped it on Gosler. And because Gosler was capable enough to actually do it, the Duke never felt the need to grow.
That was the problem, Gosler. If you don't do it, they push it on you; if you do it, they keep pushing it on you forever. Such is the tragic fate of the middle manager.
"Oh?"
"The Yetzera Labyrinth was one in Selmer Territory that we expected to stop at the 50th floor. However, contrary to our predictions, we received word yesterday that it broke through. We have to reorganize our conquest teams."
They had been rushing the conquest, hoping to finish it while it was still only fifty floors deep, but they had missed the window. Once the 50th-floor boss was defeated, it had opened the way to the 51st. Now their plans were in shambles.
"Well, we can just send the knights to another labyrinth that looks like it'll stop at fifty," the Duke said airily.
He made it sound so simple. I doubted it was. In fact, Gosler looked like he had a lot he wanted to say. Careful, Gosler—if you sigh too much, your happiness will escape.
"Like people who’ve grown attached to that specific labyrinth and really want to finish it there?" I asked.
I said it myself, but I doubted anyone was that sentimental about a hole in the ground filled with monsters. Still, there might be similar logistical issues.
"I believe I mentioned arranging support for a 50th-floor subjugation," the Duke continued. "There is an heir to a noble house I know who needs the credit. Our plan was to clear Yetzera quickly and then concentrate our forces on the oldest and most developed labyrinth in Selmer Territory... but things rarely go exactly as planned."
He said "the heir of an acquaintance noble," but he meant the successor to a house in the Duke Harz faction. If he wanted to secure the loyalty of the next generation, supporting their first labyrinth subjugation was a standard move.
It was exactly as Rutina had said. Being a faction leader was a lot of work. It wasn't just about sending them to any random 50th floor. If he couldn't deliver on a promised subjugation, they might jump ship to a different faction by the time the kids took over.
Gosler hadn't said that he’d promised Zermelo specifically to this heir. The real issue was that if you subjugated a highly developed labyrinth, the difficulty of the surrounding labyrinths would drop significantly. That was the core of the strategy.
By clearing the biggest labyrinth in the territory, the others would become easier to manage—perfect for a "first" subjugation. If the heir was talented, the Duke would give them a labyrinth with lowered difficulty. If they were a nobody, he might give them one that was still at full strength.
Perhaps they’d used Zermelo as a placeholder, but now that it had fifty-one floors, they were in a bind. The "easy" ones were likely already reserved for higher-ranking heirs.
This is what I’d call Michio’s Axiom of Choice. (It isn't.) By attempting to divide and reorganize the available "subjugation slots," you somehow end up needing to give the same slot to two different people. This is the Banach–Tarski Paradox. (It isn't.) No wonder Gosler looked exhausted.
"I see. Well, that’s some bad timing."
"Timing?"
"Actually, we finally cleared the 50th-floor boss ourselves. You mentioned you could arrange a subjugation mission, so I thought I’d take you up on the offer and have you introduce us to one."
"The 50th floor..."
If someone was already ahead of us in line, maybe he couldn't introduce us. He probably couldn't. He shouldn't. Please let it be so. Oh, what a shame that would be.
"You’re saying you’ve already cleared a 50th-floor boss?" the Duke asked, needing confirmation.
The Duke knew our general progress from our entry into the Liberation Society and the duel incident. Compared to those benchmarks, the 50th floor was quite a leap. But it couldn't be helped. We had a certain someone in our party who was hell-bent on taking us higher and higher.
"We’ve been fighting on various floors for a while now, and Rutina has become a pillar of our strength, too," I added.
Having a Mage really does make a difference. At least, that’s how I wanted him to see it. I hadn't told him she’d officially changed jobs, but if we were clearing the 50th floor, it was only natural that a Villager would have enough experience to become a Mage quickly. It wasn't a stretch to say she was pulling her weight.
"Well, I suppose clearing the 50th floor is fast, but..."
"It’s certainly fast, but did you say you cleared the 50th floor, not the 49th?" Gosler asked, picking up the thread.
Ah. I see. Now I realized where I’d messed up.
I had assumed that he would arrange the "subjugation" training after we had proven we could clear a 50th floor. I thought the sequence was: prove you can kill a 50th-floor boss in a normal labyrinth, then go kill the 50th-floor boss of a labyrinth that actually ends there.
I was wrong. That wasn't it at all.
The deal was: once you can clear the 49th floor, they introduce you to a 50-floor labyrinth whose difficulty has been artificially lowered by clearing a neighboring labyrinth. Then, you get the experience of clearing a 50th floor in a controlled, safer environment.
If you’re a normal explorer stuck at floor 49, unsure if you can survive floor 50, being able to challenge an "easy" 50th-floor boss is a godsend. It’s high-quality training and you get the prestige of a subjugation. That’s why nobles would crawl through glass to get this mediation, and why they’d be loyal to the Duke for life after receiving it.
In this world, once you reach the 40s, moving up a single floor probably takes years of training. If it didn't, everyone would be a high-level hero and the labyrinths wouldn't be a problem. The reason the world is still infested with monsters is because so few people can clear the 50th floor. It’s a massive bottleneck.
For a normal person, it might take a decade to go from floor 49 to floor 50. They’d spend years agonizing over whether they were ready to risk their lives. One wrong call and the whole party dies. So, being able to skip years of hesitation and training by taking on a "difficulty-down" boss is a massive shortcut. It might save them five or ten years of their life.
That’s a huge deal. That’s something worth fighting for. And once you're at that level, you can keep grinding the 50th-floor small fry and the 49th-floor boss. Even if the difficulty only drops a little, it’s enough of a hint to tell an explorer if they’re ready for the real thing.
Ordinary parties don't dream of going up one floor every single day once they hit the 40s. They definitely don't. Never. Do you understand that, Roxanne? That’s the point.
Sherry and Rutina couldn't see the value in the "easy 50th-floor" offer because they’d been poisoned by Roxanne’s insane pace. They were completely compromised. It might be too late for them.
Or maybe it was my fault for assuming the introduction came after clearing floor 50. I’d misunderstood the prerequisites. My bad.
"Ah... the 50th floor."
Why had I assumed that? I mean, it made sense in my head. Subjugating a labyrinth sounded like a big deal. The Duke had talked about it like a sacred noble duty. Naturally, I thought you had to clear a "normal" 50th floor before you were ready for the "final" 50th floor. That’s just logic. That’s the Axiom of Choice.
The logic was sound. My only failure was not realizing there was a middle step between the 49th-floor boss and the 50th-floor boss.
"T-That... you truly are a man of surprises, Michio-dono," Gosler said.
"Yes. Your progress is quite... alarming," the Duke added.
Stop, stop. Michio's pride is already at zero. Even Gosler couldn't think of a way to spin this.
"N-No, well, really, it’s mostly thanks to the Orichalcum Swords you gave us. That was a huge boost. And Rutina is still growing every day. It’s entirely thanks to my party members. In fact, Roxanne is already looking at the 51st floor like it’s her next snack. I’m actually worried she’s already decided we’re clearing it."
I tried to shift the blame. It was true—the swords helped. That was the Duke’s doing. But the real "problem" was Roxanne and her obsession with the next floor. It was all her fault.
"Ho? The woman with the perfect movements? She’s the same even on the 50th floor?"
"She treats the 50th-floor boss like a toddler..."
"Incredible..."
There it was. Roxanne's guilt was officially established. I hoped Gosler, as a fellow middle manager, would understand the pain of being driven by someone else’s relentless pace.
"Well then, does that mean Michio-dono is heading for the 51st floor next?"
It’s not as simple as that, Duke.
"Well... I suppose it might come to that," I said reluctantly. Unwillingly. Unintentionally. With great regret. I had no choice.
Yes, choice. I want to call the fact that floor n+1 follows floor n "Roxanne’s Axiom of Choice." The existence of the 51st floor is proven solely by Roxanne's will to be there. Just as 1+1=2 is a fundamental mathematical truth that requires deep logic to prove, the 51st floor only exists within Roxanne’s logical framework.
"Hmm. In that case, how about leaving the Yetzera Labyrinth to Michio-dono?" the Duke proposed.
He wanted me to conquer the 51st floor. Wasn't that a massive overreach? Then again... knowing Roxanne, if she had the location of the boss room, she’d probably announce that today was the day for the 51st-floor boss. Actually, she definitely would. She’d have us on the 52nd by tomorrow.
Compared to Roxanne's demands, the Duke’s request wasn't actually that bad. Even Gosler didn't say anything to stop him, which meant it wasn't a "suicide mission" by local standards.
"Mmm. The 51st floor..."
"Normally, entering a labyrinth in Selmer Territory would be seen as supporting the current Earl Selmer, which is why I haven't asked for your help there," the Duke explained. "But if it’s the final stage of a subjugation, we can frame it as a noble's duty to the people. No one can reasonably object to that."
He was being surprisingly considerate of Rutina. Since her family had been ousted in the coup, active duty in Selmer Territory would usually mean helping the regime she hated. But "labyrinth subjugation" was a high enough moral ground that he could sell it as a necessity.
Devious. Very devious.
"I see."
"Yetzera has to be subjugated eventually anyway. If Michio-dono takes it on, it frees up my knights for other duties. Aside from our elite, no other party has even reached the 40th floor yet. We have time. You could just map out the boss room and wait for the difficulty to drop before finishing it. I’m not demanding you rush the 51st-floor boss today, but if you're capable of it, I’d like you to consider it. It’s unlikely Yetzera will grow to the 52nd floor anytime soon."
Even Gosler gave me the thumbs up. If the world-weary Gosler thought it was okay, then I guess it was. Or maybe he was just happy to push the trouble onto me for once. "This doesn't even count as hardship," his eyes seemed to say.
But I had someone at home who would push even more hardship onto me. Roxanne was probably already dreaming of the 51st-floor boss. She was a runaway train.
If it was inevitable, I might as well apply the Axiom of Choice to Yetzera. Maybe I could even persuade Roxanne to wait until the difficulty dropped. The possibility wasn't zero. It was subatomic, sure, but if something is possible, it must eventually happen if you try enough times. Victory was practically guaranteed.
And even if I couldn't persuade her, I could just call it "repetitive training" on the 51st floor. A small price to pay. There was no downside to accepting.
"If you put it that way..."
"Oh! You'll do it? As expected of Michio-dono!"
"Wait, I’m the one who brought it up, but are you really okay with this?" I asked Gosler.
Hey! Gosler!
"W-Well..."
"Mhm, mhm."
"Ho! Splendid."
It wasn't splendid. I was an idiot for trusting him. The Duke should definitely give Gosler more work.
"Well, we were going to end up on the 51st floor eventually anyway."
Mostly because of Roxanne. My choice was sound.
"Truly, those who seek the liberation of the labyrinths are cut from a different cloth," the Duke praised.
I’m really not. But I’ll allow you to keep bothering Gosler. You should be the one aiming for "liberation," Duke.
"Fortunately, the explorer who scouted the 51st floor of Yetzera is still in the castle. We hadn't reassigned him yet. I’ll go call him in," Gosler said.
If Gosler ever became a "true seeker of liberation," he’d probably stop taking the Duke’s crap. He should be the one causing the Duke trouble. If you’re a "true seeker," you can get away with that. He should embrace his inner tiger.
"How heroic of you," the Duke said.
"It’s all thanks to my party," I replied.
"I knew I was right to have high expectations."
Gosler hurried out of the office, leaving me alone with the Duke. Come back quickly, Goslaemon! If Gosler ever stopped being a buffer, I’d be in real trouble. Gosler, please never stop absorbing the Duke’s nonsense.
"Michio-dono, I have the explorer. Let’s go. Please join his party."
Gosler returned quickly. He really was an essential buffer. From now on, I decided I would grant him the exclusive right to deal with all the Duke’s trouble.
"Understood. As expected of you, Gosler."
"I have no idea what you mean by that, but..."
You don't need to know. In fact, you definitely don't want to.
I disbanded my current party with Roxanne and the others and joined the party of the explorer Gosler had brought.
"Well then."
"I'm counting on you."
With Gosler seeing us off, we used Field Walk to warp from the lobby.
So this was the Labyrinth of the Axiom of Choice. The surrounding area was a peaceful, rural landscape that looked like it could be anywhere. The labyrinth entrance was right next to our warp point.
The explorer entered without a word. I followed.
"This is the 51st floor of the Yetzera Labyrinth."
Only after we were inside did the explorer finally speak. I see—talking about it at the entrance was a bad idea. There were specialized guards there. While some might be under Duke Harz’s thumb, others could just as easily be selling information for pocket change. Or worse, they might be loyal to the current Earl Selmer.
He probably didn't want the secret of the 51st floor leaking out, especially since most people weren't even at the 40th.
"Got it."
"Is there any other floor you need to see?"
"Actually, could you show me the 50th floor too?"
"Understood. Follow me."
"Mhm."
Since he was offering, I had him show me the 50th floor as well. It might be useful later. Just in case.
The explorer went out the entrance and immediately came back in. I followed. I wondered what the guards at the entrance thought of our weird behavior. Then again, it was probably common for an experienced explorer to lead a newcomer through the floors. They probably didn't think twice about it, even if he was showing me floors they didn't even know existed.
"I'm heading back to Bode. What about you?"
"This is far enough. You can remove me from the party."
Once we were on the 50th floor, the explorer dropped me from the party and left alone. I could warp home directly from here, so there was no need to go back out and deal with the guards’ stares. Even if one of two people who entered the labyrinth left alone, it wasn't like they’d immediately suspect a murder.
Probably. "Sister, there’s been an incident!"
Well, I wasn't going outside, so it didn't matter. I’d learned the guards weren't under the Duke's control, at least. No need to show my face.
I warped from Yetzera back to my house in Quratar.
"Welcome back, Master."
Roxanne was there to greet me instantly.