Couldn't decide on 1 star ot 5 stars. Like a couple of other reviews I've read, The Gray Man is so much deadlier than Jack Reacher or Mitch Rapp it's almost ridiculous. Fast Moving? As fast as a book can be. Realistic? About as unrealistic as a book can be. The problem is I really liked the book. I think I'm going to read the series but I have to look at it as more of a superhero book than a political thriller based on reality. I don't believe I've ever read a book that has any more action or a hero who absorbs as much serious injury and not only lives but keeps on winning battles. One man against hundreds of other men trying to kill him? Insane yet I did enjoy reading it in about 3 or 4 hours. The Gray Man is hard to resist. Author Greaney is probably not the author Lee Child is. Add David Baldacci, Vince Flynn or Nelson DeMille but is excitement is what you want and a book which is an incredible page turner with action which never lets up. The Gray Man is almost closer to Batman or some kind of real superhero but I'll admit this book was impossible to put down. Wild and violent? If that's your cup of tea this one is a must!