Rumors insist that this tome is the journal of a cultist, who identifies themselves as J.L.T. It's pages are purported to chronicle the cults step by step plan to end their own world, an alternate prime material plane.
If J.L.T. entries are to be believed, part of their task was chronicling their cult's success in extraordinary detail as they performed a ritual "ushering my home into the glorious Void".
It is entirely uncertain how this work found its way to the prime material plane where Jarlsburg resides. And it's authenticity is in doubt.
While the diary's veracity has been debated for nearly two centuries, the Silvercloaks have solid leads that the work has found it's way to their city, and the have learned it's intended to be auctioned off to the highest bidder.
High Inquisitor Lot strongly feels that its presence in his city and the rise of the Hungering Shadow is no mere coincidence, and every effort is being taken to find who currently possesses the books and recover it.
Anyone who reads the entirety of the Cacodex has a 33% chance of going insane upon completion. If the reader retains their sanity, they may cast Cause Light wounds 2/day and Hold Person 1/day and has a 15% chance of their alignment shifting to evil.
The Cacodex came into the possession of Adder Vitriol, the Thief Guildmaster and proprietor of it's front, Shemmy's Social Club when one of his low-level cutpurses robbed an acolyte of the Hungering Shadow who was supposed to deliver the journal to a drop off and into Malhavoc's clutches.
Adder, immediately began hearing stories of someone powerful looking for the book, so he handed it over to Krent D'Midnite to deal with.
Krent, realizing that there was demand for the journal has now set up the auction and is banking on a "big score".