I just finished reading
Chasing Ivan by Tim Tigner. I hadn't heard of him before but happened to come across his book on the free Kindle bestsellers website I run. It's short but definitely entertaining! Already purchased another book by him.
It's gone back up to $2.99 already, but the author gives it away for free as well if you sign up to the newsletter on his website.
Amazon:
http://www.amazon.com/dp/B01AAXMLVW
Author's Website:
http://timtigner.com/books/chasing-ivan