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.
For those who love adventures that put you on the edge of your seat, this is terrific.
For some reason I was not that familiar with the Cuban history as I thought. It was interesting to get some details of Cuba.