

In a video that was released on October 30, 2007, Christopher Paolini stated that during the work on the third book, he realized it would become too long and so he decided to split it into two separate books.

In an interview, he talked about a potential "book five," a prequel centering on Brom, and said that he has planned "around seven more stories set in Alagaësia - and one of those is in fact a series." Development Decision for a fourth book Since the release of Inheritance, Paolini has expressed his future interest in expanding upon Alagaësia and the Inheritance Cycle.

Because of this, many plot elements originally intended for Brisingr are in Inheritance. The Inheritance Cycle was originally intended to be a trilogy, but Paolini has stated that during writing, the length of Brisingr grew, and the book was split into two parts to be published separately. It is the fourth and final novel in The Inheritance Cycle tetralogy. Inheritance (or The Vault of Souls) is a 2011 novel written by American author Christopher Paolini. Print ( hardcover and paperback), audiobook, and e-book
