Contrived is how this novel strikes me. Contrived around a title. I suspect the title came first. It would explain a lot.
I don't buy the storyline. None of it. It has all the believability of a one hour episode of CSI: Miami dragged out to make a full-length book. I find it hard to believe that the "Messenger" in question would persue the course of action that he does...but, of course, if he didn't then there wouldn't be a novel. And, furthermore, because of the course of action he takes, I have little sympathy with him.
I'd previously read Dust To Dust by Tami Hoag and enjoyed it. If anything, this book demonstrates a lack of consistancy. It happens to the best of writers - Jonathan Kellerman, for one. Maybe this one is a blip. Still, I wouldn't recommend it if you are into crime novels that are halfway credible. I'd certainly think twice before picking up another one by her.