If you want a really good mystery set up with ghosts, read about half of this book and then stop. The ending doesn't really resolve anything and doesn't use most of it's strongest elements. There isn't enough hints in the plot for the reader to solve the mystery on their own and the answers to the major questions are just directly told to the reader at the very end of the story.
My book club picked this book based on the reviews online but in the end we were all very disappointed.