Part VII is still up for grabs!

At last! You've solved the mystery of the cards! Now that you've gotten into the hiker's computer in the hotel room, it's time to explore!

Good news! There is only one file. You double-click on it, but the smile falls off your face in an instant. More ciphers...


You might just give up on this now. You've spent so much money on airfare, and for what? Another clue?! Well, you can make an exception this time.

Let's get cracking!


Coming Soon

Transcript of Cipher


You get the ✔️ only if you are able to explain how our hiker encoded this!

  • $\begingroup$ Well, I know what it says. (Aside from a few characters for which I have a plausible guess only.) The mechanism of encoding is still mysterious... $\endgroup$
    – Gareth McCaughan
    May 22, 2019 at 2:55

1 Answer 1


The message says

In 2014, I was out for an evening jog. It was all dark. Suddenly, by the light of a nearby streetlamp, I saw someone running at me with a knife in their hands. They were about to attack me when I grabbed the knife. It slipped from my hands and -. Please help me clear my name! Go to the US embassy in Bern. You will find me waiting there.

[EDITED: The description of the cipher that used to be here was almost but not quite correct, and was not as simple as the one the OP had in mind. Here's another way to put it which I suspect is what they had in mind.]

To encrypt a message,

write down its character's ASCII codes in hexadecimal. Then ROT13 the letters and ROT5 the digits. (ROT13 is familiar. ROT5 is the same but for decimal digits: add 5, mod 10.)

  • $\begingroup$ Correct answer, but can you explain how it might have been encoded? Hint: there is a specific cipher! $\endgroup$ May 22, 2019 at 21:52
  • $\begingroup$ Well, I did explain how it might have been encoded (though there was a small error). I've cleaned up my explanation, and am now contemplating what might be a simpler way of describing the process. $\endgroup$
    – Gareth McCaughan
    May 22, 2019 at 22:41
  • $\begingroup$ OK, how about the description that's there now? $\endgroup$
    – Gareth McCaughan
    May 22, 2019 at 22:44
  • $\begingroup$ Right, and this is a process dubbed "ROT18." $\endgroup$ May 22, 2019 at 23:12

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