There are no extras in this world
When I heard that, my memories instantly snapped back to that day, four years ago.
That incident, which would turn out to be a hijacking orchestrated by Bat, was the very thing that had launched my journey through the extraordinary.
"My knack for getting pulled into trouble is in fantastic form today."
Who'd have believed I'd hear the same sentence I'd heard that day, under the same conditions? I couldn't do anything as the past played out again in front of me; I had no idea how to handle this.
"Is there a detective on the plane?" I heard the flight attendant again, right
next to me.
Man, I guess I can't just ignore this, I thought. I looked up— "…Wait. Aren't you…?"
"It's been a long time, sir. Thank you for your help before." Was a string of this many coincidences even possible?
The woman who'd nodded to me was the very same flight attendant who'd come to tell Siesta and me about the hijacking, four years ago.
"We made it through that incident safely, and it was all thanks to you, the detective, and her assistant." The woman smiled; she seemed to be in her late twenties. "As a matter of fact, I was on my first flight that day. I'm afraid I made a terrible spectacle of myself…" She sounded apologetic.
"Oh, uh, don't worry about it."
Come to think of it, she had panicked when Bat showed up. Well, new hire or veteran, it would have been weirder for any human to see a thing like that and not freak out.
"But I should introduce myself. My name is Olivia. It's a pleasure to see you again, Mr. Kimizuka," Olivia said formally.
"Are you friends, Kimizuka? …You're friends with a cabin attendant?"
Natsunagi, who'd never met the woman before, seemed perplexed. On top of that, the dubious look she directed at me seemed to imply something else.
"Not 'friends,' exactly. I just got dragged into her problem once, way back when. It's not the sort of relationship to get suspicious about."
And I have no idea why I need to justify myself at all.
"Now that you mention it, Mr. Kimizuka, you're with a different detective this time."
"Don't you drag the conversation in random directions, too!" "Are you headed to London for your honeymoon?"
"Do flight attendants always mess with people like this…?"
And why does Natsunagi look as if she wasn't actually annoyed by that comment? Don't give me that "Eh-heh-heh!" business.
"We're headed to London to pick up a little something I forgot. There's also a person we need to meet, no matter what… Although I don't even know her name," I added, forcing a smile.
"On your way to meet someone whose name you don't know… You're on yet another difficult mission, I see." Olivia smiled gently.
"And? What's going on?" I asked, thinking it was about time we got down to business.
According to Olivia, there was an incident in progress up here at ten thousand meters. And what they needed was a detective, not a doctor or the police. Had pseudohumans turned up? Or a vampire? Or was it an alien invasion?
Aw man, there were so many more options now than there had been four years ago. I was waiting for her answer when…
"Paging Miss Mia Whitlock from seat A20. When you hear this announcement, please speak to the nearest cabin attendant."
The announcement was being made repeatedly, in both Japanese and English. It was the sort of thing you heard all the time in airports…but I'd never expected to hear it on a plane. Why bother with an announcement? Why not just go directly to that passenger's seat?
Or…don't tell me. "Has she disappeared?"
Olivia nodded. She was wearing a sardonic smile. "Yes. A passenger who was here when we took off has simply evaporated."
That was the reason behind the bizarre onboard announcement: Mia Whitlock had vanished from a plane that was cruising at ten thousand meters.
"Naturally, we always check the passenger list and make sure everyone is on board before we prepare for takeoff. However, when we were distributing the in- flight meals, it became apparent that one passenger was missing." Olivia put a hand to her forehead, as if she had no idea what to do with the situation.
"Was Mia Whitlock traveling alone?" Natsunagi asked, leaning over my seat to speak to Olivia.
"Don't put your hand on my thigh, don't put your head close to me, your hair is gonna get in my mouth…" Forced to inhale the sweet fragrance of Natsunagi's perfume, I held still and listened to their exchange.
"Yes, she seems to have been by herself. About an hour after takeoff, a crew member saw someone who matched her description walking away from her seat."
I see… Was she headed for the bathroom or something?
Then, instead of returning to her seat, she'd vanished.
"Have you searched the plane?" I asked, pushing Natsunagi back into her seat. "Of course, we've looked everywhere we could. However, we haven't been
able to locate her."
"And that's why you're asking for a detective?" Yeesh. It might not be as flashy as having a pseudohuman turn up, but this still might get hairier than I'd
thought. As I was sighing about that…
"Yes. I saw your names on the passenger list, so…" Olivia's rouged lips parted in a grin.
"Hey. You had your sights set on us from the beginning."
I slumped in my seat. Olivia had asked for a detective, but she'd been counting on us all along.
…Hmm? No, wait. Something about that thought tugged at me.
"Hey, what happens if you don't find the missing passenger?" Before I could get my question answered, Natsunagi asked Olivia one of her own.
Her response was, "Well, we'll have to return to Japan." "Please don't smile when you say that. Just don't."
Apparently, the first problem we'd have to tackle wasn't finding Siesta's legacy or meeting the Oracle. It was solving a locked-room mystery at ten thousand meters.
A mystery cliché
"I smell a case," Natsunagi said, looking sharper than she really needed to. "We're pretty likely to smell something, anyway." I grimaced.
Natsunagi ignored me. She was taking a careful look around the cramped room.
You guessed it; we were in an onboard bathroom… Not, of course, for any weird reasons. We were doing a field investigation.
"Hmm. Still, I don't see anything strange… Do you?" Natsunagi reached up, touching the ceiling, but it didn't seem to have any removable sections.
Of course, there was no guarantee that Mia Whitlock had vanished from this bathroom. There just weren't many places on the plane that an ordinary passenger had access to, which made this one a strong candidate.
"Maybe she got dragged into the toilet." I knew it wasn't the right answer, but I was just saying whatever came to mind.
Four years ago, an incident had occurred at my middle school. They said that if you knocked three times on the third stall from the door at three in the morning, Miss Hanako would drag you into the toilet. However, Siesta had solved that incident brilliantly.
"Okay, Kimizuka, bend over a second." Natsunagi pointed at the toilet, trying to turn me into one of Miss Hanako's victims.
"Natsunagi, don't just use your assistant as a human sacrifice. I don't have the
guts to do my business in front of other people anyway." Unlike the former white-haired detective. "Actually, Natsunagi, that sort of bathroom play is your thing, isn't it? I figured you were kinda into that stuff."
"Don't be so casual about my fetishes! —I mean, it's not a fetish, but still!" "Oh, I see."
"Don't just give up on teasing me out of nowhere! I mean, it's fine to stop, but even so!"
Natsunagi was flailing around wildly now. Ignoring her, I checked the room over thoroughly, but didn't see anything that looked suspicious. This place seemed to be a dead end.
We left the bathroom and walked around the cabin, looking for some other hint. It wasn't that big, though, and we couldn't think of too many places where an amateur could hide. Planes built for long-distance flights had spaces for the crew to rest, but we didn't see any sign that she'd crept in there.
"Where else might she be able to hide…? The luggage compartments?"
I walked along, looking up at the luggage rack above the seats. Four years ago, I'd hidden the musket Siesta had made me smuggle up there.
"Actually, why did Mia Whitlock have to hide in the first place?" Natsunagi asked out of nowhere. "We've been treating this as a voluntary disappearance, but couldn't somebody have taken her against her will? For example—"
"She's being held prisoner?" Natsunagi nodded.
The culprit might be holding Mia Whitlock captive somewhere. We decided to keep that possibility in mind, too. Before we knew it, we'd reached the cockpit at the front of the plane.
"This was where it happened last time."
On the other side of that heavy door, I'd met Bat, and my days of fighting SPES had begun.
"Could SPES be involved this time, too?"
"With this many coincidences in play already, we can't exactly rule it out."
I'd borrowed that line; it was actually something Natsunagi had said once. She'd told me not to be irresponsible and fatalistic calling things "coincidence." We had to think about what it meant that this had happened.
There had to be more to this incident, something behind it all. Foreshadowing.
As I mulled over what it could be, Natsunagi and I returned to our seats.
"It does feel like the pieces are starting to come together, but…" I folded my arms, mentally organizing the information and clues we'd found so far.
Siesta's legacy. Our search for the Oracle. My journey with the detective. A flight attendant I'd run into again for the first time in four years. The missing passenger. A locked-room mystery at ten thousand meters. Confinement. SPES. Coincidence and inevitability. As far as other potential hints went, there was that one remark she'd made…
"I don't get it. I don't get what I don't get," I grumbled to myself, glancing at my in-flight meal. Our food had arrived while we were away from our seats.
When I thought it over carefully, it had been a long time since I'd run into such a tough, classic puzzle. Of course, when the likes of SPES were involved, nothing could be a mere game.
Either way, my brain had lost its edge, and I didn't feel anywhere near the right answer. Massaging my temples lightly, I glanced to the side, and— "… You're sure enjoying that."
Natsunagi was scarfing down the in-flight meal like a high school rugby player. She was enjoying this trip with everything she had.
"Kimizuka, you gonna eat yours?" Having polished off one meal, she started eyeing mine.
What, is there a rule that the Ace Detective has to be a big eater?
"If you say you just can't handle another bite, I suppose I could make an exception and eat that for you."
"Look, there's nothing cute about playing hard to get that way." You're just a high school girl who's highlighting her gluttony factor.
"Th-then you mean the other times I play hard to get are cute?"
"If you're aware you're just playing hard to get, does that mean you're admitting to getting all mushy about me sometimes, too?"
"I—I didn't go that far! I didn't say the earlier stuff, either!" Natsunagi was desperately trying to cover up her blunder. Great, now the playing field's even.
"Huh? What's with the mini muscle pose?" I asked.
"I'm usually the one who gets made fun of. You're the only person I ever get to be superior to."
"What, I'm at the very bottom?!"
"Well, it's more like you, me, and Charlie are having a long, messy contest for it."
"Oh, and then Yui's above us… What's the deal with this power balance?" "The problem may be that we're all less mentally mature than a middle-school
girl." However, that was a really tough problem, so I stopped thinking about it. "More importantly, what we really should be thinking about right now is the
missing passenger."
We'd found a certain number of hints, but the truth was still nowhere in sight. "Knox's Ten Commandments," Natsunagi muttered, looking serious. She'd
just finished wolfing down my in-flight meal.
"Hey, don't eat that. It's mine." I didn't know how she could keep such a straight face, but it wasn't like she'd tell me anyway.
"Knox's Ten Commandments were proposed by a British mystery author named Ronald Knox in 1928. They're a list of ten rules that must be followed when writing mysteries."
"Oh yeah, I know those. The gist was that the solutions to mystery puzzles need to be fair to readers… What about them, though?"
Granted, Knox himself went on to publish a book that broke those ten commandments; they're only one standard. Still, why would she bring them up now?
"Well, if we frame our current mystery in those terms, it might help us see something new."
"…I dunno. It might work in a regular mystery novel, but I'm not sure those rules apply to the stuff we tend to get dragged into."
For example, two of Knox's rules are "All supernatural or preternatural agencies are ruled out" and "You must not include an enigmatic figure with extraordinary physical abilities." We're currently fighting pseudohumans, so unfortunately, those rules don't cover us.
"But it's not a sure thing that SPES is involved this time, is it?"
"Well… No, it's not. So you're saying we should think of rules we could use just this one time?"
Of the ten, the one that seemed most likely to help us out with this locked room puzzle was—
" "Not more than one secret room or passage is allowable." " We accidentally said it in unison, then exchanged looks. "Okay, then if we flip that rule around…"
"Yeah. Even in an airplane, there could be just one place where someone could hide."
And that secret room had to be somewhere Natsunagi and I couldn't access easily.
Of course, our hypothesis was based on the premise that this was a puzzle in a mystery novel. But if that premise was a clue that would solve this case—
"Kimizuka, I've got it," Natsunagi said. "Listen." She pointed at me.
"When you have eliminated all which is impossible, then whatever remains, however improbable, must be the truth!"
Delivering a line worthy of the great detective Holmes, she gave me a triumphant look.
"By the way, Natsunagi, was that detective novel good? The one in the bag by your feet that you tagged all over with page markers."
"…I hate you, Kimizuka."