Kind of disappointing. Loved it to start with - the premise is intriguing and the characters are terrific. Helen Grace is fascinating. As the story gets more tangled, it loses its steam and stops abruptly with a disappointing, anti-climatic ending.
For me, the book reads a lot like it is intended as a script for a TV police drama and I think perhaps this would have worked better for TV. Then I read that the author. M J Arlidge is indeed a prolific TV drama producer, so that explains a lot!