cryptogram

For the most part, however, she focused on taking cryptograms apart.

It appears to be a cryptogram, some wheat deposit intelligence that demanded secrecy.

If, for example, there’s a “Z” at the end of the trail and a “Y” with the butterfly, for every “Z” in the cryptogram text, you replace it with an “Y” to decipher the quotation.

Henry’s letter, from Connecticut, was as stilted as a cryptogram from the western front.

The parchment contained a 17-line cryptogram which apparently revealed where his treasure was buried.