On the bottom row, one can see the even numbers from 12 to 4 (or 4 to 12, reading in the other direction). Looking for other sequences in the grid, one can find the triangular numbers from 1 to 15. After further examination, one can find four other sequences of numbers, with a term in the middle changed. This suggests that the even numbers from 2 to 12 had the first term changed (from 2 to 4), and the triangular numbers from 1 to 21 had the last term changed (from 21 to 63). In the below grid, the sequences are colored in different shades of green and the changed terms are highlighted in different shades of red:
| 2 | 13 | 20 | 1 | 18 | 2 | 15 | 2 | 9 | 1 |
| 8 | 11 | 38 | 5 | 3 | 6 | 7 | 22 | 22 | 5 |
| 85 | 23 | 31 | 11 | 63 | 15 | 10 | 6 | 3 | 1 |
| 45 | 5 | 6 | 5 | 34 | 36 | 44 | 33 | 8 | 18 |
| 1 | 3 | 14 | 18 | 48 | 31 | 28 | 5 | 2 | 19 |
| 12 | 2 | 15 | 16 | 22 | 5 | 3 | 4 | 9 | 15 |
| 9 | 17 | 9 | 21 | 15 | 2 | 23 | 11 | 7 | 4 |
| 14 | 4 | 7 | 21 | 9 | 16 | 50 | 20 | 13 | 1 |
| 1 | 6 | 5 | 1 | 32 | 3 | 1 | 7 | 47 | 2 |
| 20 | 15 | 99 | 64 | 12 | 10 | 8 | 6 | 4 | 6 |
The sequences are as follows:
The order of the sequences by position of the different term is the same as the order alphabetically by name. Taking the different terms in that order, we get 6, 9, 23, 23, 48, 63, which is useless. However, all of the different terms are bigger than the corresponding expected terms. Taking the difference between the different terms and the expected terms, we get 4, 8, 15, 16, 23, 42, which upon being searched turns out to be The Numbers from Lost. Given the four-letter enumeration of the answer, it's now clear what the answer is.
Answer: lost
Note: This puzzle was intended to not be that hard (even compared to the other puzzles). It replaced a runaround that I fully expected would mostly been done via Google Maps (and intended to be done in that way), but that I didn't think was that fun (especially done via Google Maps). If you want that runaround, contact me to ask for it.
Note: If you found a message that wasn't mentioned above, that's explained here (the linked page has spoilers for another part of the puzzlehunt too).