Whew! Long Road to Mercy is a bit schizophrenic!
I think the parentheses of Atlee Pine's back story at the beginning and end of Long Road to Mercy were too forced. I would rather have had it dosed out more slowly as we get to know Atlee Pine, rather than the way Baldacci did it which, in my opinion is "Ok! Here's her excuses for why she is the way she is, now let's move on to the plot line for this book". I think that's lazy and unimaginative writing.
The story itself is schizophrenic starting with mules and ending with ... well read it and find out. Just know it's definitely not a linear journey (which is usually OK), a bit conspiratorially far-fetched and you might need to list the characters to keep track of them all. Personally, I think Tom Clancy, Stephen Coonts and yes, even Baldacci of the 'Camel Club' novels are far better at this type of novel than Baldacci is in this one.
3.5 Stars only because Atlee Pine could be an interesting character IF Baldacci doesn't continue to crib her personality, her foibles, her pain and her traits after other popular novel heroes of other popular authors, including his own.