Igor arrived at the national convention of scientists with a bit of a conundrum. "My boss gave me this message," he tells his associates, "but says he can't for the life of him figure out what it says. He won't say where he got it or anything, but he does say he knows it's a fairly well known type of code, at least in the secret code community (igor is behind the times and doesn't actually know the word cipher or cryptography, he was always more of a biology person).

I looked some of them up but couldn't really figure anything out. Unfortunately, he says it's really important for our next project so I really need to get this figured out soon."

He pulls out the letter and hands it to the other scientists. It says:


"Any thoughts?" Igor asks. As they pass it around, though, he finally sees the back of the paper, on which is scrawled in a shaky, ugly hand:


"Oh!" says Igor, "Never mind, I got this."

What does this important message say?

  • 1
    $\begingroup$ Looks like putting it through both ROT5 and ROT21 yields... Nothing. $\endgroup$ Jan 16, 2018 at 17:02
  • $\begingroup$ It sure looks that way! $\endgroup$
    – ColdFrog
    Jan 16, 2018 at 17:02
  • 12
    $\begingroup$ Clearly Igor's boss is evcil and duplifcitous. $\endgroup$
    – Gareth McCaughan
    Jan 16, 2018 at 17:04
  • $\begingroup$ It surely some kind of substitution, given the wlg appearing twice $\endgroup$
    – bleh
    Jan 16, 2018 at 17:29

2 Answers 2


The message reads

The correct brain is buried beneath the third grave back fourth from left in plot twenty.


This is a Vigenère cipher with keyword DECAY.

ROT-5 is a crossword-style clue to the keyword.

  • 1
    $\begingroup$ Shouldve guessed that as wlg - the is 453, and rot. ugh $\endgroup$
    – bleh
    Jan 16, 2018 at 20:59
  • $\begingroup$ How did you get the word decay? $\endgroup$
    – Mohammad
    Jan 16, 2018 at 21:22
  • 6
    $\begingroup$ @Mhmd 5 letter word that is a synonym for "rot" $\endgroup$
    – ferret
    Jan 16, 2018 at 21:36
  • 1
    $\begingroup$ I have a Vigenere solver that gets pretty close to this, but I was too lazy to get it out... THE BORREBT BRAHN IS BTRIED AENEASH THE SHIRD FRAVE AACK FNURTH EROM LDFT IN OLOT TVENTY $\endgroup$ Jan 17, 2018 at 0:20

Igor pulls out an old school electrical breadboard that he keeps around for such emergency purposes and, with lightning speed, reprograms it to something indiscernible to even the experienced tinkerers in the small crowd gathered around him.

"As a long time experimenter with all things corpsey, it was pretty easy to recognize a synonym for rot with five letters, decay. I recalled from recent reading that a Vigenère cipher used a keyword to translate text to nonsense, so let's see if I can't reverse the process."

"If I've done this right, and I always do, feeding the text in should translate it back into the original message," and he pulls out a roll of finger-width paper and, with pinpoint accuracy, and the point of a pin, punches a series of holes into the strip, then feeds the paper into a slot on the breadboard.

He flips a tiny switch on the board with a tiny cackle, and the paper slides slowly, inexorably into the slot. On the other side of the board is a second slot, which the paper soon exits, first with the original punches message, then with inked letters that read:

The correct brain is buried beneath the third grave back fourth from left in plot twenty

"Ah!" exclaims Igor triumphantly, "Good, good, this is exactly what we were hoping for. And not a moment too soon, as three weather calls for severe thunderstorms in only three days!"

But then he scrunches up his face, which was impressive given the pre-existing amount of scrunchedness it already contained "Er... Huh. But who would have known to send us this message? And how? Most people we know really aren't interested in helping us with our projects..." But the rest all shrugged as they mostly try to stay out of Igor's business, as it tends to be a bit messier than they like.


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