This Book Functions as a solver of Seemingly impossible mathematical equations and an extraordinarily useful tool to manage commerce. Originally used by the Great Peddler Zidduc. and is always paired with a small coffer that functions similarly to a bag of holding, if these items are moved further than 10 foot away, the coffer will reappear next to the book the moment nothing is watching. this coffer only materialises when the book is open, or is specifically called upon using the chosen command word 

It appears as a Thick ragged book bound in black leather, with a simple metal buckle, built into the spine is a collapsible stand, seemingly to prop it up at an angle. The coffer however is a elaborately decorated platinum box with gems encrusted throughout, upon opening the box, there appears to be a huge room lined in silk, this room is 10 foot deep, and 20 foot long and wide. 

the DC for any check caused by the effects of this book is equal to 8+ the users Proficiency+ the users charisma score

Within the book is the records of every transaction that occurs within the space of 1 mile since becoming attuned

this book emanates an aura that causes effects identical to Mordenkainen's Private Sanctum in an area of a 30foot Sphere centred on the object when it is open. this book also constantly radiates an aura of the following in a 30foot Sphere when it is open :

1.  Zone of truth. this doesn't effect the attuned user, or any individual written in the book by the attuned user( Permitted individual)

the attuned user chooses a command word, any individual written in the book by the attuned user, and the user themselves can utter this command word, and a sum of their choosing that is contained within the coffer, or written within the ledger, appears in a location of the current users choosing, this can only be done when the book is open

the book automatically closes when a permitted user leaves 30ft of the book.

this book is under the effect of the spell Immovable Object, as long as the stand is Propping the book up, or the book is otherwise open

When this book is the target of a damaging spell, it will automatically cast counterspell. if it is within the radius of a damaging spell, the book is unaffected

When the book is open it is under the effect of  illusory script, the designated creatures are the same as the individuals written in the book by the attuned user. Any of the permitted individuals can also cast:

1. scrying- at will on any Merchant within 1 mile of this book
2. locate object- at will on any item recorded as a transaction in the book
3. sending-at will to any Merchant, or permitted individual
4. Distort value-double the users proficiency bonus on any item recorded as a transaction in the book, or being sold by someone within 1 mile of this book

When the book or coffer is closed it is under the effects of Arcane lock, and if its is opened not by an individual attuned, or otherwise written into the book by the attuned user, the creature opening the book or coffer is put under the effects of the Slumber form of Imprisonment. if a creature is killed while under this effect, or an object that opens this book is destroyed, they disintegrate and become written in the ledger, next to them is a sum of gold equal to 1000x the creatures CR, Level, or Objects value. nothing short of a Wish spell can bring them back