Top of the shelf at the moment. Sophie Eastlake is awesome at bringing Katie Reus' book to life as she reads it.
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.
Good writing and exciting to read. Too much sex detail for my liking. Good suspense.