In the upcoming Judas Tree, Will receives a very cryptic letter. it’s in an 8×10 inch manila envelope, and except for a cover letter from an unidentified sender, it’s pretty much nothing but a list of numbers.

The author of the letter says it’s a hit list. While the sender is confident the Will can crack it, he says very little to give him any hints. In fact he tells him that figuring out who he (the sender) is will be the key to puzzle. He did this because he doesn’t want Will figuring it out too soon.

Here’s an example of just one little piece:

165-5-2-10-1. There would be a space and then more numbers.

The Brits with their knack for code cracking would have a ton of fun with this one. What it turns out to be is a Book Cipher. Here’s how the numbers work.

65 is a page number. 5 is a paragraph. 2 is a sentence while 10 represent the word. 1 is a letter in that word.

Now here’s the problem. Whoever wrote the message and whoever received it have to have the same book. It has to be identical in every respect. If there was a difference in say font size, and this changed the number of pages in the book, the entire cipher falls apart.

Once the printing press was invented, and books became standardized, this became a very common way to send secret messages. The courier usually had no knowledge of the book, and in a properly run operation wouldn’t even know who sent it or who’s getting it (especially if another old spy trick called a Dead Drop is employed).

What’s a dead drop? I leave something someplace and someone checks on a regular basis for it. If it’s there, they take it somewhere else to leave it. Then someone else checks that location on a regular basis, finds the message, and either takes it to another dead drop location or deciphers it. If done properly, a dead drop is difficult to catch.

Will’s problem is he hasn’t a clue what book to look in. It isn’t until much later that they figure it out.

Like most things in Police Work, it’s just a matter of connecting the dots. Trouble is, sometimes you have to find the dots.

Once the book is figured out (it’s something the suspect and Will have in common. The sender knows Will has that book. In this case, they both have the exact same copy of The Kobayashi Maru by Julie Ecklar). The task of deciphering it is simple but time consuming.

The first name off the hit list is James Martinez, Plano, Texas. Will makes a simple inquiry for information from the Plano PD concerning that name, and as expected he gets several different people with that name.

The one that jumps out at him was an accidental death a few months before.

A dead guy whose name is on the hit list.

Coincidence?

Maybe not.

And there’s still a hundred and thirty names to decipher.

Stay tuned.