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.
I really enjoyed this novel, cleverly executed and great characters.
Well narrated too, a very good series, this is book 3 I think.
A really well thought out plot, brilliant and intelligent characters, and a good twist at the end. I do love this author's writing!