A Process of Elimination

When we first look at this puzzle, we are presented with a 12x12 square grid, with 3 letters in each cell. We are also given a list of 38 clues.

Many of the clues are somewhat nonsensical and/or can be answered ambiguously. Eventually, we can determine that 24 of the clues have 13-letter answers that can be found in the grid either across or down, with one letter missing. Additionally, each clue answer contains one of the words from the 1947 International Civil Aviation Organization (ICAO) alphabet. The 1947 ICAO alphabet was a precursor to the current NATO alphabet and is also known as the "Able Baker" alphabet, after the words for A and B (clued by the flavor text with Able capitalized).

If we don't notice the ICAO letters, the missing letters spell FIND LETTERS WITHIN ANSWERS, cluing the fact that we will need those ICAO letters later on in the puzzle.

At this point, we are left with 144 letters in a 12x12 grid:

The flavor text talking about going deeper into the matrix helps us know that we need to take the matrix to the next level. We can then arrange these 144 letters in a variety of ways, but if we continue the trigram pattern, we will have 48 trigrams (144 / 3). Noting we have 14 clues remaining, this clues making the new grid either 6x8 or 8x6, again with 3 letters per cell. We can notice that taking the letters in reading order allows us to make groups of 3 letters with each cell having its 3 letters in alphabetical order.

There are two ways we can arrange this grid (6x8 or 8x6), but only this way yields answers to the clues in the next section.

We can then repeat the clue process with the 14 remaining clues. There are six 9-letter answers and eight 7-letter answers to the remaining clues. Each answer can again be found in the grid. 7-letter answers are found across and 9-letter answers are found down, with one letter per cell, once again having one letter from the answer missing.

This time, the missing letters spell FIND SANDWICHES. We notice that each of the 14 answers in this part of the puzzle have a "sandwich" letter, with the same letter surrounding a different letter (e.g., DEDuction, horSEShoe or wIKIpedia).

We now have 48 letters remaining:

Using these 48 letters we can make another grid with 3 letters per cell. Once again, the trigrams we create are internally alphabetical as a check.

But we no longer have any provided clues! However the extra letters from the 2 previous rounds (hidden ICAO letters from Round 1 and sandwiched letters from Round 2) have not yet been used. Spelled out in reading order and using both the letters from Round 1 and Round 2, they give:

CITYLOFTMONKPHYSICISTROPEROSESNAKEYEAH

Or, separating on word breaks, we get the following eight clues (in alphabetical order by clue):

• City
• Loft
• Monk
• Physicist
• Rope
• Rose
• Snake
• Yeah

With 8 clues, we want to make a 4x4 grid:

Again, the answers to these 8 clues are all 5 letters long, and can be found reading either across or down in the grid. This time, we also find that the missing letter is a doubled letter.

When the letters in the answers are removed, we're left with a 4x4 grid with one letter each:

The missing / doubled letters spell DO ATBASH. Applying the Atbash cipher to the 16 remaining letters (ZMHGFIMPVBHBHGVN) yields ANSTURNKEYSYSTEM, providing the puzzle's answer: TURNKEY SYSTEM.

Authors' Notes

This puzzle was inspired by the Quote Square puzzles that are a staple in the introductory section of the monthly P&A magazines. In those puzzles, you're also presented with a series of clues and a rectangular grid with 3 letters per cell. You use one letter in each cell for each of the down and across clues, leaving you with one letter in each cell, which usually spells out a quote.

I (Dan) had the idea—what if you did a quote square, but then used the letters that remained to make ANOTHER quote square. Plus, I am a sucker for puzzles where the answer is literally staring at you the whole time. After tinkering around with different sizes, I came up with a 12x12 grid, which would then go to a 6x8 and 4x4 grid.

We tested a few different mechanisms for encoding / hiding different letters. Originally for the first round, we had used the NATO letters, but for reasons that are not that interesting, we had to switch to use a different word alphabet, settling on the 1947 ICAO alphabet.

Appendix

During the first stage, there is one possible ambiguity.

• ANGLO BOER WARS has a possible ambiguity in the 2nd to last cell, which could be either an A or R (with the other one missing). This is resolved and checked by the across answer, JOHN ANSON FORD, which requires the R in that cell.