This is the 4th book in Flynn's series. If you can, you'll really want to read them in order. This one took quite a while to get going. The first 80 pages were little else but recapping the prior three books. I think some recap is fine, but this was way too much. From there, I thought it still had trouble getting traction. Finally, about the last 1/3 of the book took off and kept me page turning.I love the serial aspect of these novels, they flow nicely from one book to the next. I also like Flynn's mixture of actual history with his fictional world.So, far of the 4 books, the 1st and 2nd have been the best for action, the 3rd and 4th were much more focused on Washington DC rather than "front line" action.Appropriateness: This book contains a fair amount of language... a word or two every 10 pages. There are characters that are hurt and killed, but none are described graphically. Sexual situations are eluded to, but are not in this book.