It's up there. I love anything Paul Morey narrates, but this book especially had an amazing storyline as well.
I liked Owen and how he grew as a character from where he was when the book started, and where he was by the end. He matured and evolved a lot.
There are many reasons why a book might be unavailable.
Sometimes a book goes temporarily out of print - and sometimes no audio version has ever been recorded. Audible wants to give you the most complete selection we can and we'll keep adding series and filling in gaps as quickly as possible.