The Let's Play Archive

Zero Escape: Virtue's Last Reward

by Fedule

Part 119: NGAE: ~/magenta/betray/red/ally sigma\$ cd ~/cyan/ally/blue/betray && chmod u+rwx *

An overwhelming majority of 63% of 292 respondents have connected the dots between Dio's long string of numbers and Alice's pressing need for a long string of numbers and want to see where that goes.

The game actually starts you from right after Alice's huge flashback, but I have mercifully elected to skip that. When we left off, Alice was commenting that the Myrmidons are fond of using long strings of numbers as decryption keys.

Listen in: [English/Japanese]

("He Was Convicted of a String of Numbers")

I was almost as surprised as she was.
The numbers had just kind of...appeared in my mind, and I was saying them before I knew what I was doing. Alice looked at me incredulously, and I stared back.

VLR OST: [Clarification]

Where did... Wait...
Can you say that again?

Uh... 78153 61098 83809 42419 90551.


That number you just told me...
Prime factor decomposition on that number gets you 198449351 to the third power.

You're talking about reducing an integer to a series of prime numbers that you multiply together to get it, right?
Like, if you have 30, then you'd get 2 x 3 x 5, right?

Exactly. You probably learned that in junior high, right?

So you're saying that 198449351 is a prime...
And if you multiply it by itself three times, you'd get 7815361098838094241990551?


Don't tell me you just did all of that in your head...

What?! No! No way! That's impossible!

I told you. I'm better at math than most people.

That's not "better at math"!

Well, look at you—you just recited a huge string of numbers.
That seems pretty astounding too.



I didn't know what to say. What would I tell her? That it just came to me?

Can't tell me, huh? Fine.

I'm pretty sure that's the key to the code, though.
I know the Myrmidons use prime factors for their keys...
And there aren't a lot of twenty-five-digit numbers that turn out to be the third power of a prime number...

I think there's a very good chance that number you memorized was specifically created by someone.

U-Uh... Could you explain that with...small words?

Well, look at the prime factors of your number:
198449351 to the third power. I think that's our hint for cracking the code.


You still don't get it?
Try to remember the code we saw in the infirmary.
What did it say on the monitor?

Um...I think the first row was...

And the second row?

Then they just repeat.

We could really use someone like you back at the—um...

Well? Keep going. How do we decode that?

You use 198449351 to point you to the right letters.

How do we do that?

The next number is 9, so go nine letters over from the first one. Then eight from that one...
Just keep going until you get something.
Make sense?

I ran over what she'd said in my head.
The prime number Alice had given me was 198449351. So what would we get if we picked out letters like she'd explained?

The first letter would be "C," from the top left.
Then you'd move nine to the right, which would give you "O."
Then eight more to the right...

Eventually we'd get a word.
And that word was...

Yes, we do actually have to figure it out ourselves.

Yes, the Vita version is uniquely hamstrung by the lack of a second screen, and it was apparently beyond the programmers to allow you to switch between this screen and the answer input screen at will.

Better safe than sorry, I guess.

I mean, could they not have just given you the coded message and key as archive items? There's an archive access button right there for chrissakes! And the memo-pad. There's no shortage of ways to remember stuff.

Speaking of remembering stuff...

...I forgot the code.

[Music fades out]

VLR OST: [Desperation]

Listen in: [English/Japanese]

Hey! Get off my back! If I don't know, I don't know!

Ugh. Just forget it. I'll figure it out on my own.

She stalked off.


I went to follow her, but—

Stay where you are! I don't have any use for another braindead man!

Her voice was unexpectedly furious, and it stopped me cold. She fixed me with an icy glare, then turned and stalked off. I stayed frozen where I was and watched her go.


Welp. Clearly Alice was too angry to be able to decode the message herself given the key, even though she can perform prime factor decomposition of a 25-digit number in her head in seconds. Also everyone died for some reason.

By the way, prime factor decomposition takes a computer super-polynomial time in the number of digits involved [citation needed]. What I'm saying here is that Alice is
unreasonably good at numbers.

I mean, like, of all the stuff in this game that is straight-up fantastical,
this thing is what actually bugs me. A computer could do that sum in a fraction of a second - a 9-digit prime-factor is tiny in cryptographic terms - but Alice is still doing the equivalent of like 5 million calculations per second in her head here. I'd love to get some input from someone who actually has some degree of understanding of the time complexity of factorization algorithms on this, though. Y'know, to help put this lunacy in perspective.

Anyway... you guys can crack this code, right?