This book is, in a word, astounding.

I literally *just* finished reading it and don't even know where to begin reviewing it. There is so much I want to say but I have also been rendered a little speechless. 

Although the book is technically YA I found it to be a very complex and thought provoking exploration of the cyclical and concentric nature of time, space and the human experience, disguised as post- apocalyptic science fiction.