Like millions of people, I've read every Jack Reacher anything since the first book and after finishing one am anxiously awaiting the next one. What might set me apart is that I'm a book behind - I don't start the second to the last book until I know a new book has been written and that Reacher isn't dead. Weird? Perhaps, but Reacher is such a great character that you just want the series to go on forever; in that I'm probably no different than all Reacher fans. For me, it's less important what the book is about, because we know at the end Reacher is going to save the day and if he wants, get the girl then continue on wherever he feels like going. So, I'm writing this review for the new Reacher reader.
Maybe this is your first Reacher book. If it is, may I suggest you go alllllll the way to the beginning of the series and get to know Reacher. Although each book can certainly be read as stand alones, your experience will be richer for having known Reacher from the start. There are always nuggets of information in each new book that ties up a loose end from a previous book - even if you didn't know the end was loose. There's always a new layer, a different wrinkle, a new understanding that is built upon, that shouldn't be missed. That's the beauty of reading all the Reacher books from the beginning.
Anyway, if you know and love Reacher like the millions of us do, you know this offering follows the format as all the other Reacher books, and you're okay with that. All I'll say in terms of what this book is about is that there are old friends and foes in involved and I know that Reacher is doing well now because his new book comes out in September; see you the book after that......Regards, a Reacher Fanatic