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Once upon a time, somewhere in Italy, two archaeologists unearthed a buried passage.

As they explore the passage they reach the doorway which is clearly the entrance of a wide structure behind. They see well-built passages made of square stone walls. There are passage branching in various directions.

One of them exclaims:

-- It's a maze!

And indeed, it is. Very excited about their finding, they want to explore it. They start arguing about the best way to proceed without getting lost. But they stop when they see the following engraving on the wall.

stone maze

-- Look at this, a map! Not much of a challenge. I'm a bit disappointed. What's the point of building a maze if you just put the full map at the entrance? That doesn't make any sense! Well, let's see what is at the other end.

The other doesn't reply, absorbed in his study of the engraving, scribbling on a notepad. Eventually he gasps and becomes pale.

-- That's not a map, it is a message. It is a warning!

-- A warning?

-- Yes, I know where this maze ends, and we definitely shouldn't go there!

From what you have seen and what you have read, can you tell me what the message says and where to the maze is leading?

Hint:

Forget steganography, hidden pixels or color filters. If you copy the maze on a notebook it should be good enough to solve it.

For reference:

╶─────────┬───┬───────────┬─────╮  
╷ ╶─────┬─┴─╴ ├─┬─╮ ╭───┬─┤ ╭─╮ │  
│ ╶─────┴───╮ ╵ ╵ ╵ ╰─╮ ╵ ╵ ╵ ╰─┤  
├─────┬─╴ ╷ ╵ ╶─────┬─┴─╴ ╭───╮ │  
├─╴ ╷ │ ╭─╯ ╶───┬─╴ ╵ ╭───┼─╴ ╵ │  
│ ╶─┼─┼─┤ ╶─┬─┬─┴─────╯ ╶─┴─╮ ╶─┤  
│ ╶─┤ ╵ │ ╷ ╵ ╰─╮ ╶─┬─╴ ╭───┴───┤  
│ ╶─╯ ╷ ╵ ╰─────┴─╴ │ ╶─┴─┬───╮ │  
├─────╯ ╶─────────┬─┴─┬───┴─╮ ╵ │  
│ ╶───┬───╮ ╭─╴ ╷ ╵ ╷ ╰───╮ ╰─╮ │  
│ ╶─╮ ╰─╴ ╰─┴─┬─┴───┤ ╶───┴─╴ ╵ │  
├─╴ │ ╭─────╴ │ ╷ ╷ ╵ ╶─────────╯  
╰───┴─┴───────┴─┴─┴─────────────╴  

Cont'd

-- A warning? What does it say?

The first archaeologist just shows his notepad. At the bottom you can see 3 lines of text, nicely aligned, 11 characters in width. The second one reads it and agrees.

-- If this is correct, we better get out of here.

Cont'd 1

-- But how did you even think it could be a message?

-- It is the ... well ... entropy of the map. There is no symmetry, no long corridors, the branching pattern is complex, there are way to many short dead ends. That is not how you build a maze. Looking at the map I could see that its complexity is uniform. I felt that the placement of each wall conveys hidden information.

-- I can't say I got that feeling. Is it so?

-- Yes. As I discovered, no wall is placed just randomly. Every single wall contributes to the message.

Cont'd 2

They are now on the surface, back to the car, eating a sandwich before hitting the road.

-- Funny the thing you told me earlier. I never realized that.

-- Which one? I am always funny.

-- Yeah, well... debatable. Anyway. It was about the pillars and the walls. That there are exactly as many pillars in a labyrinth as there are walls between the pillars.

-- That's true for every perfect maze. But that is not interesting. The interesting part is that one can match pillars to adjacent walls in a perfect one-to-one relationship. It is like one pillar with one wall form a unit.

-- Interesting... You give me an idea. If we want to go into the business of building prefabricated mazes, we just need to produce one type of piece, a pillar with an attached wall? That would work for every possible labyrinth? You never need an extra pillar or an extra wall?

-- Exactly. You still need to build the outer wall, of course.

-- We can subcontract that.

Epilogue

-- OK. There is still something I don't get. When you display a warning, you want to make it readable, right? Like bright yellow text on red background. What sense does it make to display it in such a cryptic way?

-- I can only guess that warning is a legal requirement. And they don't like it. So they found a loophole to comply without really complying.

-- They must have found the one lawyer who could think of such a thing.

-- I bet they are not short of that kind.

Florian F
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  • there must be some words or smth – AntsPiano May 31 '21 at 21:58
  • Is knowledge of a language other than English required to solve this? – JProblems Jun 01 '21 at 00:00
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    No italian, no latin, only english and a bit of general knowledge is required. – Florian F Jun 01 '21 at 08:26
  • does the maze form a word? – AntsPiano Jun 01 '21 at 19:39
  • Well, it says it is a message. There is a cipher tag. – Florian F Jun 01 '21 at 19:47
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    This puzzle is driving me crazy! It is getting better with every new hint. – Dmitry Kamenetsky Jun 03 '21 at 12:50
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    Maybe it was too difficult to start with. I will keep adding hints until it becomes solvable. – Florian F Jun 03 '21 at 12:54
  • I think it could be related to the extended ascii characters that allow you to draw lines... – Dmitry Kamenetsky Jun 04 '21 at 03:45
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    Converted to comments as suggested by @bass: A possible start towards a partial answer...

    The hint marked "Cont'd" indicates rot13(jr fubhyq trarengr n tevq bs 3 k 11 yrggref fbzrubj. Vtabevat gur obeqre, gurer ner 15 k 11 vagrevbe abqrf, juvpu pna or qvivqrq vagb tebhcf bs 5, znxvat n 3 k 11 tevq) visualisation: https://i.stack.imgur.com/1nyKN.png

    – Steve Jun 04 '21 at 09:29
  • This would be the correct dimensions if rot13(rnpu tebhc bs 5 vagrevbe abqrf naq gurve cnggrea bs pbaarpgvat jnyyf pna fbzrubj or pbairegrq vagb n punenpgre. Va cevapvcyr, rnpu bs gurfr obkrf pbhyq rapbqr hc gb 10 ovgf bs vasbezngvba ba nirentr, qrcraqvat ba juvpu nqwnprag jnyyf ner cerfrag gb rnpu bs gur 5 vagrevbe abqrf. Gur yngre uvag "Pbag'q 1" frrzf gb vaqvpngr gung gurer'f nobhg n pbafgnag ragebcl yriry jvguva gur tevq, fb n fpurzr nybat gurfr yvarf, rira vs abg qvivqrq rknpgyl yvxr gung, znl or gur jnl gb tb.) – Steve Jun 04 '21 at 09:29
  • Some further possible progress (perhaps into a blind alley) was that I noticed that rot13(gur ovanel rapbqvat bs tebhcf bs 5 iregvpny yvarf jnf nyjnlf va gur enatr 0-24, naq hfvat gung nf na vaqrk vagb gur nycunorg, cneg bs gur svefg frg vapyhqrq "N S B B Y". Hasbeghangryl abar bs gur erfg znqr frafr jvgu gung xvaq bs rapbqvat) – Steve Jun 04 '21 at 09:34
  • what do you mean by "Pillar"? – simonalexander2005 Jun 04 '21 at 13:18
  • @simonalexander2005 in the visualisation linked in my earlier comment, each box contains 5 "pillars". The answer somehow relies on the fact that rot13(rnpu jnyy va gur znmr pna or havdhryl yvaxrq gb n fcrpvsvp cvyyne. V gevrq pynffvslvat cvyynef ol jurgure gur nggnpurq jnyy vf ubevmbagny be iregvpny. Guvf ntnva erfhygrq va ovanel inyhrf orgjrra 0 gb 25 va gur obkrf, ohg V jnf fgvyy hanoyr gb znxr nal frafr bs gur erfhygvat yrggref jura vaqrkvat vagb gur nycunorg.) Also noticed rot13(gur jrfgzbfg pbyhza bs cvyynef pbagnvaf bayl jnyyf nggnpurq gb gur rnfg naq jrfg bs gur pbeerfcbaqvat cvyyne.) – Steve Jun 04 '21 at 14:07
  • @Steve: Is there any better luck using the encoding rot13(vs lbh hfr zbefr? Gur jnyyf naq cvyynef erzvaq zr bs qbgf naq qnfurf.) – APrough Jun 04 '21 at 15:32
  • @APrough I'm not sure where I'd start with applying that, but do feel free to investigate if you think that idea has legs! – Steve Jun 04 '21 at 15:35
  • Technically a horizontal wall should count as a floor or a ceiling. :-) – Florian F Jun 04 '21 at 16:09
  • Pillar: a strong column made of stone, metal, or wood that supports part of a building. – Florian F Jun 04 '21 at 16:10
  • @Steve: I've just come back to read the comments again having posted my answer (you got credited since some of your comments helped me understand the hints better). I've just noticed that your latest comment seems to basically be the method I successfully used so not sure how it went wrong for you! :( I'm wondering if you were off by one on your conversions? And thank you to Florian for the hints. It always makes me sad when a really interesting seeming puzzle like this gets no correct answers but no useful updates meaning I never know what the puzzle was all about. – Chris Jun 04 '21 at 17:53
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    Even though the encoding process is reasonable simple, it didn't make the puzzle easy. As I realized, the problem is that there was no clue for the decoding process, no hint at the method or any suspicious pattern to work on. In that situation all one can do is to guess how one could encode a message in a maze and try it to see if I used that. The possibilities are endless. It ends up as a "guess what I was thinking" puzzle, which is not very interesting. I added the hints to make up for it. But I'd say a good puzzle should provide from the start such a trail of clues to follow. – Florian F Jun 04 '21 at 19:09
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    @Chris it probably would be an off-by-one error - for some reason it didn't occur to me to try offsets before investigating various different ways to extract a bit from the "one of 4 compass directions" I'd recorded for each pillar. I'd probably have gone back to it later on that day if I hadn't seen the answer already! I'll see if I can salvage a partial answer that "shows the work I did" but of course crediting you for putting the final steps together next time I'm on the computer that had the spreadsheet I was using for analysis... – Steve Jun 05 '21 at 18:36
  • @FlorianF that's more or less what I was thinking - I went off in a wrong direction early, and even at that point there were so many possible ways stuff could be encoded. – htmlcoderexe Jun 16 '21 at 08:44

3 Answers3

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The message says "abandon all hope ye who enter here" which suggests that this maze leads to hell! (According to Dante's inferno which says that this messages is inscribed over the door to hell).

Here's how I got there. I needed all the hints and Steve's comments under the question were useful before I saw the latest hints.

First of all an annotated version of the maze:

annotated maze My annotations are labels for each "pillar" of the maze saying whether its attached wall is horizontal or vertical. Green lines helped me to work out whether the wall was a horizontal or vertical...

Once I had 33 sets of 5 orientations (read top to bottom and then left to right) I changed those strings to binary numbers: h being 0 and v being 1. I then converted these binary numbers and used them as indexes into the alphabet. eg hhhhv = 00001 = 1 = a, hhhvh = 00010 = 2 = b, etc. 0 was a space and the ends of columns were also word breaks.

Chris
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    A collective congratulation for this excellent team work! – Florian F Jun 04 '21 at 18:45
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    Thank you! I can finally sleep in peace... – Dmitry Kamenetsky Jun 05 '21 at 01:47
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    I've now undeleted the "possible start towards a partial answer" that I'd then converted to comments given the lack of confirmed progress, as it was a lot closer to an actual answer than I'd thought, and seems to expand the background behind this answer. Also note that I was still considering about half a dozen other options besides the ones that seemed "surprisingly close" and which I thus considered comment-worthy. – Steve Jun 07 '21 at 07:15
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Although initially labelled conservatively as "A possible start towards a partial answer...", this turns out to actually have been the core of the actual answer, increased to more than 90% with the final comment, so I'll now undelete and "finish off" the part that had been posted as comments for easier access to how that answer was determined.

The hint marked "Cont'd" indicates that

we should generate a grid of 3 x 11 letters somehow.

I fairly quickly noticed that

ignoring the border, there are 15 x 11 interior nodes, which can be divided into groups of 5, making a 3 x 11 grid:
visualisation of grid divided as described

This would be the correct dimensions if

each group of 5 interior nodes and their pattern of connecting walls can somehow be converted into a character.

In principle, each of these boxes

could encode up to 10 bits of information on average, depending on which adjacent walls are present to each of the 5 interior nodes.

The later hint "Cont'd 1" seems to indicate that

there's about a constant entropy level within the grid, so a scheme along these lines, even if not divided exactly like that, may be the way to go.

The first (failed but suspiciously close) attempt was to

look at which "vertical" walls were present, and to use the binary code as an index to the alphabet. This resulted in:

   01   08   04    B    I    E
   02   15   15    C    P    P
   00   16   16    A    Q    Q
   05   01   05    F    B    F
   14   04   20    O    E    U
   14   24   02    O    Y    C
   11   05   08    L    F    I
   04   01   05    E    B    F
   00   02   18    A    C    S
   05   21   05    F    V    F
   08   08   00    I    I    A
   12   14   00    M    O    A 

It seemed "suspiciously close" because

all indexes were in the range 0-24 despite 0-31 being technically possible. At that point I tried various offsets (e.g. 0=A or 1=A or even 2=A), and got nowhere, so figured there was "something wrong" with the encoding.

I'd meant to look back more closely at the question for hidden clues about what to do next. Instead, "Cont'd 2" was posted, after which it was clear that

the directions of the walls "attached" to each node/pillar were important, so I recorded them:

 E E E E N W N E E E E E N E S
 E E E N W W N N N N W N N N E
 W W W W S N E E E E N W S W W
 W S N S W E E S W N E E S W N
 E E N W E E E E E E N E E S E
 E N N N S N N W E S W E E E E
 E N S N E E E N W S E N W W W
 W W W E E E E E E E E E N W N
 E E E E S S W S N S N W W N W
 E S N W E E S W W W E E N W N
 W S S W W W S S S N E E E E E 

This still left open

various ways to extract information from the groups of 5 pillars that still only really remained an "initial hunch" based on the first significant clue of 3 x 11 letters. Even if we're only considering a 5 bit code (which was far from certain at that point, I'd also wondered about other possible ways to have 8 bits encoded in the 10 raw bits available), which two directions should be considered "1" bits and which "0" bits, or is there some other encoding entirely? My first attempt was actually stupidly close, where "E" and "W" are interpreted as 0 bits, and "N" and "S" are interpreted as 1 bits...

   01   08   05    B    I    F
   02   15   14    C    P    O
   01   16   20    B    Q    U
   14   05   05    O    F    F
   04   00   18    E    A    S
   15   25   00    P    Z    A
   14   05   08    O    F    I
   00   00   05    A    A    F
   01   23   18    B    X    S
   12   08   05    M    I    F
   12   15   00    M    P    A 

However, I then tried different ways to extract a bit (resulting in different kinds of garbage) rather than trying something that would have easily let me see the actual message:

using 'A'-1 as the base rather than 'A'+0 resulting in:

   01   08   05    A    H    E
   02   15   14    B    O    N
   01   16   20    A    P    T
   14   05   05    N    E    E
   04   00   18    D    @    R
   15   25   00    O    Y    @
   14   05   08    N    E    H
   00   00   05    @    @    E
   01   23   18    A    W    R
   12   08   05    L    H    E
   12   15   00    L    O    @ 

Fortunately, @chris was able to see the step that I missed, and complete an answer before @florian-f got even more frustrated at how close I was getting in comments and then just missing the actual answer!

Steve
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  • A "start towards a partial answer" is something that should be a comment. And as you say, it's not quite certain that this post constitutes even that. – Bass Jun 04 '21 at 08:55
  • @bass I initially thought "it wouldn't fit in a comment", but now tried, and actually did manage to fit it into a pair of them.... not sure if you'll see this comment, given I'll be deleting answer shortly. – Steve Jun 04 '21 at 09:31
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Partial answer:

This is the path through the maze. It is exactly 33 tiles long.

enter image description here

the tiles clearly correspond to the 33 characters.

I have considered various encodings based on each path tile being only one of four possibilities.

There are two ways I could encode - either the tile's entrance direction or its exit direction. Not much difference, the characters get shifted by one.

I have tried UDRL and NSWE, nothing interesting popped out.

I considered WASD as in the keys you would traverse the maze with but no.

I am wondering if DNA is somehow involved because it is also encoded with 4 different letters and commonly grouped in 3s as well! But I don't know which turns would correspond to which of ACTG.

Another possibility is that turns only navigate and don't have a meaning - the message characters are each tile's possible exits. This gives 16 possible values per character, 15 in practice as the "all closed" tile cannot be entered. I cannot begin bruteforcing the possible ways to assign these either.

All in all a hint may be in order, or someone else can use this to come to a better conclusion.

htmlcoderexe
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  • rot13("gur gvyrf pyrneyl pbeerfcbaq gb gur 33 punenpgref." Ubj pna lbh or fher?) – Joseph Sible-Reinstate Monica Jun 02 '21 at 16:50
  • Bit too coincidental I think. But you're right it could have been something else. Don't forget, this is supposed to be limited by what one can do with basically paper and pencil. – htmlcoderexe Jun 02 '21 at 16:54
  • I wondered if the coordinates of each cell of the path may be relevant but can't think how that would work... – Chris Jun 03 '21 at 09:45
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    @JosephSible-ReinstateMonica In fact, the latest hint seems to suggest that it might not be the case at all. – Admiral Jota Jun 03 '21 at 15:19
  • @AdmiralJota yep the new hint invalidates most of my thinking here. I do not know what is the best etiquette here - do I post s second answer, do I edit this one or do I delete this one and post a new one? I won't be able to get to this for another few hours either way... – htmlcoderexe Jun 03 '21 at 15:43
  • There's also rot13(33 pbyhzaf, gubhtu 14 ebjf frrzf n ovg zhpu gb rapbqr rnpu yrggre) – Mohirl Jun 03 '21 at 16:43
  • are you sure it is 33 as I only counted 16? – htmlcoderexe Jun 04 '21 at 10:14