There are plenty of action of course and some plots and twist in the story although the story was mostly fairly predictable. I guess I have read too many of these kind of books by now to be easily surprised. It has a nice build up of the mystery parts. Not too rushed as in many books. In general it is a decent story and a good book.
What I expected to be a pre-historic shark horror-thriller turned out to be a soap opera filled with thoroughly unlikable people mostly spending their time promoting their own careers, cheating, bad mouthing, scheming, backstabbing and any other unpleasant activity you can think of.