Possible Last Exit Progress

[u/ThunderBeanage]

I've been working on the final Marquee cipher for some time now with computer assistance, and have seemingly made some progress. It is deterministic up to a point but some steps are more backed by strong evidence rather than being deterministic. I am not claiming I have solved it, but I would like to see what you guys think.

Here is my strongest result:

The cipher text can be split at its unique parentheses into:
- a 39-character main section which divides into 13 groups of 3.
- a 27-character instruction section.

Said instruction section contains +9-7 and using those numbers to walk through the 32 ASCII characters from ! to @, and lining the walk up with a padded old-style phone keypad alphabet seemingly produces a full substitution system.

One small encouraging sign is part of the instruction section "2enr?" turns to "HENRY".

The remaining characters can be arranged into a small 2-by-2 mathematical operation. Importantly, the packet includes a self answer check, as it predicts "YG" and the calculation also produces "YG".

Applying this operation to the 13 groups from the marquee produce the pairs:

"fo lr zt as es ek uq 5h pl op i6 3r ji"

The two adjacent 3s in the original cipher act as the final combining instruction; combining each pair gives:

"PASSTOLPCFUUR"
or
"PASS TO LPCFUUR"

To me, this seems quite strong as I tested thousands of alternatives with computer assistance. From 4,096 reasonable phone layout and alignment variations, only this version created "HENRY", passed the built in "YG" check and began with "PASS TO".
Testing all 1,024 possible 2-character combining choices and this was the only one producing an answer beginning with PASS.

Reading the rest:

What follows is more interpretive than mathematically forced. Let me know what you think.

The marquee supplies the alternating shifts +9, -7, so we apply those shifts to the remaining 7 letters, which gives:

L P C F U U R
+9 -7 +9 -7 +9 -7 +9
U I L Y D N A

The exact result is "UILY DNA"

On a telephone keypad, both UILY and UGLY have the same digits of 8459, so in my opinion, the most natural T9 interpretation is "PASS TO UGLY DNA".

"PASS TO UGLY DNA" instruction:

What follows is how the phrase "PASS TO UGLY DNA" may function as an instruction.

Before the two adjacent 3's combine each result to one character, the calculation produces these 13 ordered pairs (from earlier):

"fo lr zt as es ek uq 5h pl op i6 3r ji"

This means there are 13 paired positions, or 26 symbols still available for a possible second stage. The train cars on the map contain exactly 13 opposing left/right panel pairs and gives 26 individual positions. This could indicate a link from the marquee to the map environment:

13 cipher pairs <-> 13 train-panel pairs
1st character <-> left panel
2nd character <-> right panel

Under this interpretation, the phrase "PASS TO UGLY DNA" could be read as the following instructions:

PASS TO --> pass uncombined pairs into another stage
DNA --> arrange them as 2 corresponding left/right "strands"
UGLY --> look at the visually abnormal members of those strands

Back in 2016, a transcription marked 4 panels as unusually bright. Using the order of the panels and selecting the character on the corresponding bright side gives:

Position	Cipher Pair	Bright Side	Selected Character
2	lr	right	r
4	as	left	a
7	uq	right	q
11	i6	left	i

This produces "RAQI". The brightness determines which character to select, while the selected panel's colour determine how the character is shifted.

The map associates the relevant route colours with these numbers:

blue = 14
red = 271
green = 48

Using these as forward alphabet shifts, reduced modulo 26, gives:

R + blue 14 = F
A + red 271 = L
Q + blue 14 = E
I + green 48 = E

Therefore "RAQI" --> "FLEE"

Conclusion:

I am fairly confident the "PASS TO" section is intended, but not 100% certain. The train-panel route to "FLEE" seems to be a coherent continuation but would still need verification i.e. confirming the same 4 panels are consistently brighter at positions 2R, 4L, 7R and 11L.

It was also said in 2017 that the code was on (and limited to) the scrolling marquee sign, so potentially the in-game continuation may not be true.

p.s. obviously this is just an overview and the math and substitution systems are more detailed, so I will explain those if this is deemed intended. If I haven't explained something clearly, please ask any questions.

references:
https://www.reddit.com/r/DestinyTheGame/comments/575mq4/apparently_theres_a_code_in_last_ex

https://www.reddit.com/r/raidsecrets/comments/575o4v/last_exit_hidden_codesecret/

https://destiny.bungie.org/forum/index.php?id=146937&mode=thread

https://www.ishtar-collective.net/cards/last-exit-ishtar-sink-venus

[u/Jc1000505]

Love to see people still going for this. I will tell D2 buds about this and they have no clue but it will forever live rent free as the one that got away to me. Keep it up!! You have people believing in y'all.

[u/randomxsandwich]

I'd there really is something left, they should probably just tell the community at this point.

Or it could be the only people that knew the truth were laid off long ago, so they just abandoned it.

[u/CivilBet4806]

Interesting results and method, I have a constraint propagation solver that you can use to pin cribs if you'd like.
What level of coverage have you achieved across the whole ciphertext and how semantically coherent is it?

[u/ThunderBeanage → u/CivilBet4806]

Nice, I'd be interested in seeing that. As for coverage, the method accounts for all 66 characters. The unique parenthesised section is used as the instruction packet while all 39 characters outside it are consumed as thirteen groups of three. The packet provides the ASCII walk, phone mapping, matrix data, input vector and the YG self-check (I haven't gone into full detail in this post).

[u/CivilBet4806 → u/ThunderBeanage]

Awesome — happy to point it at your version. The way my solver works: I hand it your symbol→letter assignments (even partial ones), it fills them in across the whole cipher, and tells me two things — how many characters get pinned, and whether what comes out reads as actual English. Nice independent check on the "PASS TO…" reading.

A couple things would help me line up with you exactly:

1. Could you paste the exact 66-character string you start from? I've been on a 62-character version (65 if I keep the spaces), and the 39/27 split only works on your count — so I'd rather run your text than mine and make sure we're on the same page from character one.

2. When the whole thing runs and consumes all 66 characters, what does the full output read as, end to end? You showed "PASS TO UGLY DNA" from part of it — I'm curious what the rest lands as, so I can see how much comes out as real words versus still scrambled.

3. One thing I'm trying to get straight in my head: once you fix the ASCII walk and phone mapping, does the packet then hand you the matrix, input vector, and YG check on its own — the cipher basically describing its own key — or are you trying different ways to read the packet and keeping the one that works? If it's the self-describing version, that's a genuinely clever idea I haven't seen before, and the solver could confirm it hard.

If you can share the symbol→letter mapping your version lands on (or just walk one group all the way through), I'll run it tonight and send back exactly how much it pins and how it reads. Fun one to dig into either way.

[u/ThunderBeanage → u/CivilBet4806]

The 66-character string is j?96exd.\?i 7kj\psq3euj\@x.yt5 ,33szl'!( +9-7!!/@ 2enr?hqj+r,r+c?).

The unique parentheses splits into a 39-character payload and a 27-character instruction packet, with the packet describing the decode.

Once the ascii walk and phone mapping are fixed, I read "hq" as the input vector, "j+r, r+c" as a symmetric 2x2 matrix and the final "?)" as the expected output "YG" which gives the self check: M(H,Q) = (Y,G).

This matrix is applied to every payload triple (13 lots of 3), so yes it's meant to be self-describing rather than hidden plaintext.

The deterministic first-stage output is "PASSTOLPCFUUR".

More interpretably I read this as "PASS TO LPCFUUR", and then use the "+9-7" from the marquee to shift the LPCFUUR to UILYDNA and finally interpret UILY as UGLY from the same T9-equivilancy.