So, I had read that you can pretty much read this without having read the previous Eragon books, which I think is true for the most part. Since it's been 20 years since Eragon first came out, I figured I'd be okay because I definitely don't remember any of details from the first four books. There are references to events and characters that I definitely could not remember, but I could follow what was  happening with Murtagh. 

This book is very much about Murtagh dealing with his past trauma, not only when he was working for the evil king, but also just his unbringing in general. There are some tough moments in this book, both for Murtagh and for Thorn. 

Also, I forgot how long winded Paolini is. I don't think this book necessarily needed to be this long, but it's not surprising that it is. There's some unresolved things, so I wouldn't be surprised if Paolini also revisited this world again in the future, either with Murtagh or with Eragon. I'm sure we'll be getting more books.