An interesting book by P.D. James is her CHILDREN OF MEN. Her only foray into science fiction concerns a future world where the entire population has become infertile. Very interesting, thought provoking, and suspenseful. I liked it more than the movie made from it, although the movie with Clive Owen (The Croupier) is very good -- just different.
Have only read one book by Jonathan Kellerman, Peace. His GONE.
Supposed to have been a thriller, but I found if only boring. Like you, I finished it, hoping it would get better, but it didn't.
Marj