Possible details that this book will unveil.
Since The Book of Bill will give out more information about Bill Cipher and other characters from the show, here are some possible info that the book will reveal:- The History of the Nightmare Realm: Considering what we have seen of Bill's dimension and how bizarre it looks, we will most likely learn what it originally looked like and how Bill liberated it.
- The origin of the Henchmaniacs: From what we know of Bill's lackeys from the show, one of them apparently decimated countless worlds. The book will give out more facts about all of the Henchmaniacs. Such as where they all came from, their personal lives, how they ended up in the Nightmare Realm and met Bill.
- Bill's connection with the Northwests: At the end of "Northwest Mansion Mystery", there was a scene with a large mural of Bill Cipher. This implied that the Northwest family has a history with Bill. There will be an entry that details how Nathaniel Northwest encountered Bill Cipher and made a deal with him in order to obtain fame and fortune in exchange that Nathaniel and his entire family will worship him. Thus, this will explain how a so-called "village idiot" managed to usurp Quentin Trembly as the founder of Gravity Falls.
- More information on the Axolotl: At the climax of "Weirdmageddon part 3", Bill referred to the cosmic being by name in a backwards message pleading to be resurrected prior to his demise. While there have been two books that mention the Axolotl, this book will have several pages detailing the Axolotl's role in the universe, and its connections with Bill.
- Bill inspiring the Eye of Providence, a Christian symbol representing God's benevolent gaze, despite being a demon will be explored.
- Bill's time with Ford: While Journal 3 did give out details on Ford and Bill's friendship up until the incident with the dimensional portal and Bill's aforementioned betrayal, the book will give out more aspects of these events with Bill even mentioning the times that he possessed Ford's body.
- Bill's backstory and the Second Dimension's destruction. We'll learn more about Bill's family, how he came to discover his Reality Warper powers, and why he decided to destroy the Second Dimension.
There will be a few nods to Amphibia and The Owl House.
Considering that both shows are implied to be set in the same universe as Gravity Falls, The book will have a few pages that allude to them in some form. For example, Bill will mention about a dimension where the inhabitants are anthropomorphic frogs, toads, and newts and learned that they had created a way to travel to other worlds. Bill will further elaborate that he hopes that their dimension hopping will lead to them finding the Nightmare Realm where he'll easily manipulate them. Another example will have Bill talk about a dimension filled with magical beings that live on top of a long dead giant.- Bill will reference coming across Philip Wittebane and the Collector. He has a very low opinion on both of them, the former for having such insanely petty reasons for committing genocide, even by Bill's standards, and he'll make fun of the latter for not understanding death even though he taught Belos the Draining Spell and how he finds his Freudian Excuse to be an Ass Pull.
- Bill will turn out to have played a part in the creation of The Core. He'll also call Marcy Wu an even more annoying fusion of Dipper and Mabel.
- There will also be a few nods to Star vs. the Forces of Evil, also implied to take place in the same universe. Bill will turn out to be the Greater-Scope Villain of Season 4 through manipulating both Mina Loveberry, the Magic High Commission, and even Star and Marco, before commending Star for succeeding where he failed by causing mass hysteria from merging two worlds together. However, it also turns out that Glossaryck is his Sitcom Arch-Nemesis.
Bill will return... but as an entirely new character.
- In accordance with what the Axolotl said about Bill, the only way for him to absolve himself of his crimes, he would be reincarnated into a new form. However, even if he successfully returned, there would be consequences for it. As such, perhaps Bill wrote the book as recompense for his previous acts.
Much like in Journal 3, there will be a few Rick and Morty references
Though the current status of Alex Hirsch's relationship with Justin Roiland after Roiland's Role-Ending Misdemeanor is currently unknown, it's still pretty much canon that Gravity Falls exists within Rick and Morty's multiverse. Plus, the idea of Bill going up against Rick Sanchez is too awesome to pass up.There will be a reference or two to Inside Job, due to it being created by Shion Takeuchi and the heavy involvement of Alex Hirsch
Bill will offhandedly mention some nerds calling themselves a Shadow Board who want to unleash him onto the world, but he's more interested in the potential usefulness of Reagan and Rand Ridley. It'll also serve as one last beacon of hope for fans of that show after it was Screwed by the Network.