as a kid processing laura's loss so after 9/11 and the violence that came of a g it including daniel peris murder, i returned to that idea that if i wasn't going to be overwhelmed by this i had to understand it and that was when i embarked on that project he mentioned that algorithm. >> and cia approaches you and take the job and a start looking at cables and there was one in particular that i think but this is before you were received -- when you realize that a man who had been taken and beaten and starved was the the wrong man. and i'm wongdingering if you can talk about that moment -- and how you reacted other people around you reacted. >> yeah. i won't get into the sort of operational details on that anymore than they're in the book just because they've been kind of reviewed and elements that were necessary have been omitted so i'll let it stand as it is written. that particular case was covered very thoroughly and widely and heavily in the press. but i think that it's -- i think that it's indicative of one of the great challenges that we all a faced after 9/11 by we all i mean america