Indeed, this novel is a more a full fledged techno thriller. It's the sort of book Clive Cussler, Graham Hancock and Dan Brown would come up with, should they ever team up together to write something.
The pace is intense, from start to finish. So much so that I feel that several sequences were a bit rushed. I felt that certain portions should have been more fleshed out, especially the events occurring in Berlin and Ethiopia. In my opinion, John Twelve Hawks could have elaborated a bit more without losing the rhythm he established in The Traveler.
The characterization is an interesting facet of this book. Not only do we learn more about Gabriel, Maya, Michael and other characters from the first volume, but we are introduced to some new faces like Mother Blessing. The author demonstrates how ruthless he can be, and the body count among main characters is impressive.
The storylines comprising The Dark River showed a lot of promise. And yet, the fact that the author speeds through most of them in the narrative doesn't allow him to exploit their potential to the fullest. I'm acutely aware that I don't say this very often, but this book should have been longer.
Regardless of those shortcomings, the reader keeps turning those pages. Short chapters that jump from one POV character to the next create a nice balance between the "good" and the "bad" guys.
It's been pointed out in other reviews: The cliffhanger ending is a bit annoying. Especially since we now have to wait for about two years to discover how it all ends!
Still, The Dark River should satisfy fans of The Traveler and keep them begging for more!
The final verdict: 8/10