For their winter 2018 limited quarterly edition, known simply as “Clandestine”, the people at Field Notes teamed up with “puzzle event” company The Mystery League to craft a 3-pack of memo books focused on cryptography and secrecy.

First, watch the video, which has got to be among their most beautifully shot:

There are some interesting features added at the back of these Field Notes:

The last page of each book features a three-part history of codes and ciphers with many examples and anecdotes. There’s also handy cross-reference matrix of various codes on the back covers, because you never know when you’ll need to crack something.

As cool as that sounds, it gets even better — the 3-pack comes with a “F.I.E.L.D. Agent” ID card that, once you’ve cracked the codes within the memo books, will “assign” you a field office, an expertise, and a supervisor.

Get a 3-pack of the “Clandestine” Edition for $13 at Field Notes.