I just got done reading a book from one of my favorite authors and found myself seriously annoyed at it. So, like I usually do, I pondered why I was so upset with the book. Because writing-wise, it was fine. So what annoyed me?
As I pondered, I realized that it had the same problem that I've run across in many other middle books. So I broadened my pondering, and pondered why middle books are often so bad in comparison to other books in the trilogy or series.
As I pondered, I drew myself pictures to define concepts better for myself.
There seem to be a two kinds of series:
- A series of books -- no overall arcs:

- A series with arcs carried over multi books:

Since I read for character, my reading repertoire contains, almost exclusively, the second type of series. So that's what I focused on in my further ponderings.
As I pondered, I came to the conclusion that there seem to be two kinds of problems with middle books, which can appear in either type of series, but as I said, I'll focus on the second type of series.
First Middle-book Problem
The first problem with many middle books is that they are really the first part of the end book, or the next book.
In other words, the last two books in the trilogy are not two books, but really one book that has been split into two parts.

Since I'm an author, it seemed obvious to ask:
When you are writing a book, how do you tell the difference between two separate books, or one book in two parts? (Read more)