This book apparently contains a helpful appendix supplementing the characters, history, with maps. This is not the only audio book that would be enh..Show More »anced significantly if Audible would make such supplementary info available with a pdf. In the past, I've usually been able to find some of this stuff at authors web pages, but not this time. So rather than review the incomplete book (which I really haven't finished), let me just warn others that it is challenging to keep all of the characters and locales herein straight without a program. I nevertheless found the main character engaging, and the plot lines including a cadre of spies and the prospect of religious war on the part of the Persians in the 3rd century interesting.