I've read all of Clancy's books and this is by far the worst - pure garbage and a waste of time to read. The characters are unbelievable, the plot is unimaginative and easy to anticipate, and the open-ended finish is lame.... I mean come on - two untrained twins let loose by a "private" vigilante group to hunt down and kill suspected terrorists - all the while flying 1st class, driving the finest cars, staying in five-star hotels and planning / discussing their "hits" at sidewalk cafes. It's James Bond meets Maxwell Smart. I'm sure the real Jack Ryan is turning over in his literary grave. Don't waste your time or money on this one.....