All I can say is WoW!!! The 6th Extinction was a wild, very thought provoking ride!! The maps, the science, the characters and the plot kept me riveted. In order to get sleep at night, I had to force myself to put my kIndle away. Not an easy feat. Did find it a little unsettling, since so much in the book is being done now. I think this is the best Sigma Force book of them. Thank you, James Rollins for writing this book!!