I thought this book was excellent and I can't wait for the sequel. This was a new genre for me, having only ever read one previous thriller, though that doesn't adequately describe this book because it has a little of everything: sci-fi, thriller, espionage. Some of the other reviewers didn't like the amount of detail and though I could have done without it, not being very interested in weaponry or technology, I can see that many people would enjoy that and for them it would add to the story. I did learn a great deal about submersibles and how they work and there's never anything wrong with acquiring knowledge. There were a lot of characters but I soon realized I didn't really need to keep track of all the minor ones and the major ones were very evident. To fault this book on those, in my opinion, minor details is to do it a disservice. I thought it was very original and it always kept me wondering what was going to happen next which I found refreshing since I can usually see where most books are heading. No chance of that with this one. I'm not used to reading books with a lot of violence (I realized a thriller would have that, though, of course) but I had to overlook that because I absolutely had to immerse myself in this book. Even a migraine couldn't stop me from reading.
It was frighteningly believable and would make a very absorbing movie. The espionage angle was just as enthralling as the sci-fi, if not more so. A great premise, realistic characters and situations, and great plot development. This book was a gift but I will be buying the sequel the moment it becomes available. I'm sure we'll be hearing more about Mr. Chen in the future.