At what point in the writing process for Brisingr did you realize you had more content than a single book could contain? Was it necessary for you to perform a kind of literary surgery to separate the books?
Good question. Few people ask about that. . . . The realization came about a third of the way through Brisingr. At that point, I started doing the math and realized that if I continued writing the story at the same pace, the book would end up being around 2,000 pages long—far too long for anything but a dictionary. It was a difficult thing to wrap my mind around since I’d always thought of the series as a trilogy and was ready to move on to other things once the third book was done. However, in order to do justice to the story, it needed more space than originally anticipated.
Figuring out where to break the story was probably the hardest part of the process. Since I didn’t plan on there being four books, I had never tried to devise a plot point that could stand as the end of the third book, nor a plot point that could serve as the beginning of the fourth. It took a bit of thinking before I was able to come up with a suitably exciting series of events. Mind you, the overall story wasn’t altered, but the emphasis shifted slightly. If Brisingr and Inheritance had remained a single volume, then the character death that ends Brisingr would have taken up slightly less space.
The split is also the reason that I gave each of the last two books in the cycle subtitles (Brisingr: The Seven Promises of Eragon Shadeslayer and Saphira Bjartskular and Inheritance: The Vault of Souls). To me, they’re still separate halves of the same novel, and the subtitles help differentiate one from the other.
* Editor’s note: Christopher answered this question for the Book Passage blog back in October of 2011.