I'm intending to provide a run-through of some thoughts and observations I've had that might help us form a plausible interpretation of the otherwise mysterious 'symbol' that appears both inside, and on the envelope of, the Halloween card sent to Paul Avery in 1970. To start, then, here's the base symbol in question, as it appears inside the card:

The line that I am planning to take is one that essentially questions the symbol being mysterious at all. In fact, it should be noted from the outset that I shall not be thinking of it conventionally as, in fact, a symbol of any kind, but rather as a straight-up drawing or sketch of something, together with a number of annotations added for the purpose of conveying certain pieces of information—specifically, aspects pertaining to where we are to look for this 'something', and where to search on it, once we get there.

It is common to encounter the error of supposing that we can simply begin with the raw bearing we have applied to the map, couple this with the stated scale of 6.4 miles to the inch and then just run the math. It is, however, not as simple as this.

The Phillips 66 Map used by The Zodiac is, as we shall find, actually not scaled at anything close to 6.4 miles to the inch, nor is the straight-up direction (Map North) properly aligned to True North. It is for these reasons that, through ignoring these combining deviations, we find ourselves regularly presented with proposed bomb locations that do not match the location that would have been obtained by simply following the instructions and laying off the coordinates on the map, as given.

The starting point, then, must be a detailed analysis aimed at identifying the precise degree of each of these primary deviations. And, to do that, we must start with the map itself.

Topographically we have the sloping hillside with adjacent road, surely frequented by school buses for both day outings as well as regular school runs, all combining to meet the logistics of the detailed mechanism we had drawn for us. Yet, more than just this, there is something oddly compelling about the existence of precisely these features at such an elevated and visible landmark—there for all the inhabitants of San Francisco to see and notice daily.

Were there to have actually been an explosion here, people would have been able to stand and point towards it from wherever they found themselves, with only the minimal of effort. With a telescope or an excellent pair of binoculars, it could even be scoped from the very peak of Mount Diablo itself. Even a search here for an ultimately absent device would have been enough to draw the daily attention of tens of thousands at a time.

The North-East face of the twin-peaked hill—precisely that face where the bomb would have to be placed to catch the early morning Summer sun—is just the very face which looms in the distance from many a vantage point along the majority of Market Street, heading west.

And maybe—just maybe—it is a schematic for these very Peaks that we have encoded in the otherwise mysterious symbol added to the Halloween card.

In any event, if there is any new potential solution I see offered to the Z32 cipher, my first thought is always to check whether it will reach from Mount Diablo along the "eighth radian" to somewhere around the middle of the San Francisco Peninsula, and I am all the less excited whenever it doesn't.

""Mr. Z" was a pseudonym used by columnist Nicholas Kristof in 2002 to describe a suspect.....The columns suggested "Mr. Z" may have been involved in the anthrax attacks or previous hoax letters."

https://www.theatlantic.com/magazine/archive/2010/05/the-wrong-man/308019/

The Z-shaped image is coined from the Bates Letters signature.....it is identical in every way.

1. the first and the twenty-sixth letter must be the same;
2. as, also, the second and the final (thirty-second) letter;
3. and, finally, the same for the sixth and the fourteenth letter.

This is all that we have to work with.

Yet, it is perhaps worthwhile considering the question as to why it was these specific three constraints that the author chose to give to us at the outset, and not any of the alternatives that must have been equally possible.

Why, in particular, does he seem especially keen to direct us to the relationship between the very beginning and end of the cipher?

Here I'm going to be using only an old version of Microsoft Word and a copy of the Zodiac Phillips Map. The example I'm going to be working with is one chosen completely at random, but which nonetheless has a nice, natural 'read' to it.

We use, then:

AT FOUR AND A THIRD INCHES RADIAN EIGHT

from:

'RADIAN EIGHT', here, assumes the given division of the superimposed compass rose over Mount Diablo, which The Zodiac has suggested we divide into twelve equal sectors of 30° each. Radian eight, therefore, it that "radial line" extending from Mount Diablo at a bearing of (8 × 30°) + 17° = 257° from map north, the last term added to make the adjustment to Magnetic North, as indicated.

Let's get into it, then.

(Work in progress, this thread will attempt to house all the basic information about the Beale ciphers.)

https://en.wikipedia.org/wiki/Beale_ciphers

https://en.wikisource.org/wiki/The_Beale_Papers

From Wikipedia:

The Beale ciphers are a set of three ciphertexts, one of which allegedly states the location of a buried treasure of gold, silver and jewels estimated to be worth over $60 million as of January 2025. Comprising three ciphertexts, the first (unsolved) text describes the location, the second (solved) ciphertext accounts the content of the treasure, and the third (unsolved) lists the names of the treasure's owners and their next of kin.

Beale 1:

71 194 38 1701 89 76 11 83 1629 48 94 63 132 16 111 95 84 341 975 14 40 64 27 81 139
213 63 90 1120 8 15 3 126 2018 40 74 758 485 604 230 436 664 582 150 251 284 308 231 124 211
486 225 401 370 11 101 305 139 189 17 33 88 208 193 145 1 94 73 416 918 263 28 500 538 356
117 136 219 27 176 130 10 460 25 485 18 436 65 84 200 283 118 320 138 36 416 280 15 71 224
961 44 16 401 39 88 61 304 12 21 24 283 134 92 63 246 486 682 7 219 184 360 780 18 64
463 474 131 160 79 73 440 95 18 64 581 34 69 128 367 460 17 81 12 103 820 62 116 97 103
862 70 60 1317 471 540 208 121 890 346 36 150 59 568 614 13 120 63 219 812 2160 1780 99 35 18
21 136 872 15 28 170 88 4 30 44 112 18 147 436 195 320 37 122 113 6 140 8 120 305 42
58 461 44 106 301 13 408 680 93 86 116 530 82 568 9 102 38 416 89 71 216 728 965 818 2
38 121 195 14 326 148 234 18 55 131 234 361 824 5 81 623 48 961 19 26 33 10 1101 365 92
88 181 275 346 201 206 86 36 219 324 829 840 64 326 19 48 122 85 216 284 919 861 326 985 233
64 68 232 431 960 50 29 81 216 321 603 14 612 81 360 36 51 62 194 78 60 200 314 676 112
4 28 18 61 136 247 819 921 1060 464 895 10 6 66 119 38 41 49 602 423 962 302 294 875 78
14 23 111 109 62 31 501 823 216 280 34 24 150 1000 162 286 19 21 17 340 19 242 31 86 234
140 607 115 33 191 67 104 86 52 88 16 80 121 67 95 122 216 548 96 11 201 77 364 218 65
667 890 236 154 211 10 98 34 119 56 216 119 71 218 1164 1496 1817 51 39 210 36 3 19 540 232
22 141 617 84 290 80 46 207 411 150 29 38 46 172 85 194 39 261 543 897 624 18 212 416 127
931 19 4 63 96 12 101 418 16 140 230 460 538 19 27 88 612 1431 90 716 275 74 83 11 426
89 72 84 1300 1706 814 221 132 40 102 34 868 975 1101 84 16 79 23 16 81 122 324 403 912 227
936 447 55 86 34 43 212 107 96 314 264 1065 323 428 601 203 124 95 216 814 2906 654 820 2 301
112 176 213 71 87 96 202 35 10 2 41 17 84 221 736 820 214 11 60 760

Beale 2:

115 73 24 807 37 52 49 17 31 62 647 22 7 15 140 47 29 107 79 84 56 239 10 26 811
5 196 308 85 52 160 136 59 211 36 9 46 316 554 122 106 95 53 58 2 42 7 35 122 53
31 82 77 250 196 56 96 118 71 140 287 28 353 37 1005 65 147 807 24 3 8 12 47 43 59
807 45 316 101 41 78 154 1005 122 138 191 16 77 49 102 57 72 34 73 85 35 371 59 196 81
92 191 106 273 60 394 620 270 220 106 388 287 63 3 6 191 122 43 234 400 106 290 314 47 48
81 96 26 115 92 158 191 110 77 85 197 46 10 113 140 353 48 120 106 2 607 61 420 811 29
125 14 20 37 105 28 248 16 159 7 35 19 301 125 110 486 287 98 117 511 62 51 220 37 113
140 807 138 540 8 44 287 388 117 18 79 344 34 20 59 511 548 107 603 220 7 66 154 41 20
50 6 575 122 154 248 110 61 52 33 30 5 38 8 14 84 57 540 217 115 71 29 84 63 43
131 29 138 47 73 239 540 52 53 79 118 51 44 63 196 12 239 112 3 49 79 353 105 56 371
557 211 505 125 360 133 143 101 15 284 540 252 14 205 140 344 26 811 138 115 48 73 34 205 316
607 63 220 7 52 150 44 52 16 40 37 158 807 37 121 12 95 10 15 35 12 131 62 115 102
807 49 53 135 138 30 31 62 67 41 85 63 10 106 807 138 8 113 20 32 33 37 353 287 140
47 85 50 37 49 47 64 6 7 71 33 4 43 47 63 1 27 600 208 230 15 191 246 85 94
511 2 270 20 39 7 33 44 22 40 7 10 3 811 106 44 486 230 353 211 200 31 10 38 140
297 61 603 320 302 666 287 2 44 33 32 511 548 10 6 250 557 246 53 37 52 83 47 320 38
33 807 7 44 30 31 250 10 15 35 106 160 113 31 102 406 230 540 320 29 66 33 101 807 138
301 316 353 320 220 37 52 28 540 320 33 8 48 107 50 811 7 2 113 73 16 125 11 110 67
102 807 33 59 81 158 38 43 581 138 19 85 400 38 43 77 14 27 8 47 138 63 140 44 35
22 177 106 250 314 217 2 10 7 1005 4 20 25 44 48 7 26 46 110 230 807 191 34 112 147
44 110 121 125 96 41 51 50 140 56 47 152 540 63 807 28 42 250 138 582 98 643 32 107 140
112 26 85 138 540 53 20 125 371 38 36 10 52 118 136 102 420 150 112 71 14 20 7 24 18
12 807 37 67 110 62 33 21 95 220 511 102 811 30 83 84 305 620 15 2 108 220 106 353 105
106 60 275 72 8 50 205 185 112 125 540 65 106 807 138 96 110 16 73 33 807 150 409 400 50
154 285 96 106 316 270 205 101 811 400 8 44 37 52 40 241 34 205 38 16 46 47 85 24 44
15 64 73 138 807 85 78 110 33 420 505 53 37 38 22 31 10 110 106 101 140 15 38 3 5
44 7 98 287 135 150 96 33 84 125 807 191 96 511 118 440 370 643 466 106 41 107 603 220 275
30 150 105 49 53 287 250 208 134 7 53 12 47 85 63 138 110 21 112 140 485 486 505 14 73
84 575 1005 150 200 16 42 5 4 25 42 8 16 811 125 160 32 205 603 807 81 96 405 41 600
136 14 20 28 26 353 302 246 8 131 160 140 84 440 42 16 811 40 67 101 102 194 138 205 51
63 241 540 122 8 10 63 140 47 48 140 288

Beale 3:

317 8 92 73 112 89 67 318 28 96 107 41 631 78 146 397 118 98 114 246 348 116 74 88 12
65 32 14 81 19 76 121 216 85 33 66 15 108 68 77 43 24 122 96 117 36 211 301 15 44
11 46 89 18 136 68 317 28 90 82 304 71 43 221 198 176 310 319 81 99 264 380 56 37 319
2 44 53 28 44 75 98 102 37 85 107 117 64 88 136 48 154 99 175 89 315 326 78 96 214
218 311 43 89 51 90 75 128 96 33 28 103 84 65 26 41 246 84 270 98 116 32 59 74 66
69 240 15 8 121 20 77 89 31 11 106 81 191 224 328 18 75 52 82 117 201 39 23 217 27
21 84 35 54 109 128 49 77 88 1 81 217 64 55 83 116 251 269 311 96 54 32 120 18 132
102 219 211 84 150 219 275 312 64 10 106 87 75 47 21 29 37 81 44 18 126 115 132 160 181
203 76 81 299 314 337 351 96 11 28 97 318 238 106 24 93 3 19 17 26 60 73 88 14 126
138 234 286 297 321 365 264 19 22 84 56 107 98 123 111 214 136 7 33 45 40 13 28 46 42
107 196 227 344 198 203 247 116 19 8 212 230 31 6 328 65 48 52 59 41 122 33 117 11 18
25 71 36 45 83 76 89 92 31 65 70 83 96 27 33 44 50 61 24 112 136 149 176 180 194
143 171 205 296 87 12 44 51 89 98 34 41 208 173 66 9 35 16 95 8 113 175 90 56 203
19 177 183 206 157 200 218 260 291 305 618 951 320 18 124 78 65 19 32 124 48 53 57 84 96
207 244 66 82 119 71 11 86 77 213 54 82 316 245 303 86 97 106 212 18 37 15 81 89 16
7 81 39 96 14 43 216 118 29 55 109 136 172 213 64 8 227 304 611 221 364 819 375 128 296
1 18 53 76 10 15 23 19 71 84 120 134 66 73 89 96 230 48 77 26 101 127 936 218 439
178 171 61 226 313 215 102 18 167 262 114 218 66 59 48 27 19 13 82 48 162 119 34 127 139
34 128 129 74 63 120 11 54 61 73 92 180 66 75 101 124 265 89 96 126 274 896 917 434 461
235 890 312 413 328 381 96 105 217 66 118 22 77 64 42 12 7 55 24 83 67 97 109 121 135
181 203 219 228 256 21 34 77 319 374 382 675 684 717 864 203 4 18 92 16 63 82 22 46 55
69 74 112 134 186 175 119 213 416 312 343 264 119 186 218 343 417 845 951 124 209 49 617 856 924
936 72 19 28 11 35 42 40 66 85 94 112 65 82 115 119 236 244 186 172 112 85 6 56 38
44 85 72 32 47 63 96 124 217 314 319 221 644 817 821 934 922 416 975 10 22 18 46 137 181
101 39 86 103 116 138 164 212 218 296 815 380 412 460 495 675 820 952

.