While I agree with other reviewers that this book is reminiscent of both Daphne du Maurier and Kate Morton, I feel that it is so much more. First of all, you have the enticing setting of the Hebridean Islands which the author evokes so well. Then you have a fantastic mystery from the past to be solved. Add in a little of Lady Chatterley's Lover ( yes, romance ), and a dash of gothic melodrama and you come up with a book that you may not be able to put down.
Yes, the older story is more interesting than the modern one, and Hetty is a bit of a doormat. But this suits the author's purpose well, enabling her to keep the momentum of the plot going. Like a murder mystery? That's in there too.
So, in a word, read it!