Monogatari Series - Volume 23 - Chapter 1.06

006

I told Meniko that I could treat her to tea or something as thanks, but she politely declined, saying she had the next lecture to attend—well, that was the case for me as well, but unlike Meniko, I was flexible. The fact that I was not in the least reluctant to skip out on lectures was the same as in my high school days.

And, more simply, I had no time to waste.

Because it was an oddity phenomenon that involved a vampire, I needed to do as much as I could before the sun set—it’s good to have a shelter against every storm.

After all, I’d even nearly been torn to shreds by mummies standing on the boundary line of life and death, unclear whether they were living or dead.

If I was going to have to confront the vampire itself—well, since I was under Gaen-san’s management, it probably wouldn’t develop into a battle, but it would still be better if I could resolve things before Kagenui-san arrived.

As such, I followed my navigation and traveled from Manase University to the Naoetsu General Hospital using the shortest paths possible. After arriving, I called the number of Gaen-san’s PHS that I’d gotten from her when we’d parted ways, and had her tell me where Kuchimoto-chan’s hospital room was—I’d foolishly wondered if, now that a third victim had appeared, it would be better to put them all in one large room for the sake of convenience, but it seemed Gaen-san wanted to keep them separate.

Well, if those related to the female students (mainly their families) ended up sharing strange information, it could cause a huge uproar—it was probably better to deal with each one of them as its own separate case, with “cause unknown”, under the pretense of confidentiality, so as to keep this terrifying supernatural phenomenon behind closed doors and not cause a panic.

Of course, there had to be limits to that, but…

“Hey, Koyomin. You got back pretty quick, didn’tcha?”

Next to Kuchimoto-san, who’d been changed into a patient gown and laid on the bed like the two before her, Gaen-san, who was placing some sort of charm (vampire-sealing?), turned to look at me.

“Did you solve the code? I’d be happy if you said you did. Something a little inconvenient happened on my end, so I’d love to hear some good news.”

“Huh. It’s pretty unusual for something inconvenient to happen for you while I wasn’t there.”

“Totally.”

Though she wouldn’t offer any details, it seemed something truly inconvenient had indeed happened—although, unfortunately, I hadn’t been able to return with good news that could make up for that.

Thanks to Meniko, the code I’d been assigned had indeed been solved, but that didn’t change the fact that I had no idea what it meant—of course, this was just an amateur’s judgment.

Perhaps, if I presented Meniko’s solution (decryption) to Gaen-san, a specialist, it would be something immediately recognizable for her.

“My friend, who’s planning on majoring in cryptography, solved it in ten seconds. It was actually a bit too quick to be satisfying, but it was a code that a high schooler thought of, after all.”

But it wasn’t a code that couldn’t be solved.

I put the flashcards on the shelf by the bed and tried to make my explanation brief.

“‘B777Q’. If we take it apart, it’s made up of a ‘B’ and a ‘Q’ with three sevens in between them, but what characteristics do the ‘B’ and ‘Q’ have in common?—although, I shouldn’t need to start showing off like that in front of you, Gaen-san.”

“No, it’s fun. Keep going like that.”

Even if you encouraged me…

Well, I was happy that she was going along with my self-redemption, now that I noticed it. It seemed she had some good points, when I actually could speak to her like this.

“Well, to sum it up, for the capital letters ‘B’ and ‘Q’ that look completely different when written in uppercase, they end up becoming the same shape, but rotated, when written in lowercase as ‘b’ and ‘q’—and, if we think of them having the same shape, then there’s a pair of Arabic numerals that also have the same shape.”

“That’s true. I’m well-aware of it from playing Uno.”

“Um, it doesn’t matter whether you know about it from playing Uno or not.”

It was “6” and “9”.

And, as you can see, “6” and “9” more or less had the same shape as “b” and “q”—in other words, after substituting them, we could come up with the equation that “B777Q” equals “67779”.

“B777Q” = “67779”.

“Oho. I see, I’m following you so far. But what does the number ‘67779’ mean exactly? Do you have an interpretation for that?”

“Though she’s aspiring to major in cryptography, that friend, like me, is a mathematics student, so when she sees a number lined up like this, she’s the kind of person that thinks of prime factorization first, you see.”

“What an annoying kind of person.”

“Indeed. However, without even needing to do prime factorization, it should be clear as day that we can split ‘67779’ into three prime numbers. That is, ‘67/7/79′.″

“How is that even clear as day? Something like that is fainter than looking at a ghost.”

Gaen-san shrugged her shoulders as if she was astounded.

Even an onee-san that knew everything couldn’t know this as thoroughly as a code maniac and a prime number maniac could.

“So? How do you interpret ‘67/7/79’ next?”

Of course, without even needing me to explain what prime numbers were, Gaen-san sought out the next step of the decryption—she was certainly good at using people.

“Well, we had a step where we converted the alphabet into Arabic numerals, right? So it’s an orthodox method of doing the opposite now and turning the Arabic numerals back to letters of the alphabet.”

“Hm… So is it ‘S/D/V’?”

She was sharp.

Yes… “67” was the 19th prime number when you counted from “2”. Similarly, “7” was the 4th prime number, and “79” was the 22nd prime number.

“67/7/79” = “S/D/V”.

“If she managed to figure that out in ten seconds, then I can’t look down on college students these days, huh. Well, I don’t have any complaints so far, but I still don’t understand what ‘S/D/V’ is supposed to mean. You still have more, right?”

“Yes… I’m sure you probably realized this, Gaen-san, but for every piece of a flashcard, there’s always a backside… In the same handwriting as the front side, the numbers ‘231’ were written.”

“I hadn’t realized it, though. Don’t overestimate this onee-san too much, because I’d hate to disappoint you youngsters. ‘231’? Since it’s obviously divisible by ‘3’, it’s naturally not a prime number. Although, among the titles of Maurice Leblanc’s works, I think there was something like ‘313′.″

“Since it had been specifically written on the back side, we should take this not as another code, but as a sub-key to use as a hint… That is, it could be pointing out the order.”

“The order? So, we should take the three letters pointed at by the code on the front side, and put them in the order of ‘2-3-1’, like an anagram? So basically, ‘S/D/V’ becomes ‘D/V/S’…”

“S/D/V” = “D/V/S”.

It was likely that, in order to give off an air of perfection, the code had been rearranged to show the three sevens, “777”, and this was an operation to put everything back.

Even I thought that “B777Q” looked better than “77QB7”.

Putting it all together…

“B777Q” = “b777q” = “67779” = “67/7/79” = “S/D/V” = “D/V/S”.

That was it—I was happy that I was being overestimated with her saying “Araragi-chan, who’s so much smarter than me”, but really, Meniko, arriving at something like this was impossible for me.

However, for a code maniac like Meniko, her decryption only went as far as this—just because “S/D/V” was “D/V/S”, it still didn’t change the fact that it was completely meaningless.

We could only decipher up to here for now.

However, if Gaen-san continued to say, “I still don’t understand. You still have more, right?”, then I’d have to throw my hands up—but the onee-san that knew everything stayed silent.

“……”

Without pressing further, and without even stating her own thoughts, she put a hand to her mouth, quietly behaving as if she were deep in thought.

Was there an interpretation that a specialist could make, as I had hoped? Could “D/V/S” be some sort of specialized term used by specialists… For example, something like “Dracula vampire soulless”… 

But, as if chiding me for thinking something so stupid, Gaen-san said, “This is indeed an abbreviation, but these are initials, Koyomin. For example—the initials of a name like, ‘Deathtopia Virtuoso Suicidemaster’.”

“D/V/S” = “DEATHTOPIA VIRTUOSO SUICIDEMASTER”.