I definitely would recommend this novel to a Deborah Crombie fan, especially if that fan was up to date with the back stories of Duncan and Gemma's life together and their blended family. That background, and the "private" lives of those in their circle, does intrude on the darkness and complexity of the murder investigation. Therefore, I wouldn't recommend this book to a new reader unless that reader intended to continue with the series.
The case being investigated by Gemma and her D.S. Melody Talbot, has a back story too, and I'm not sure the reader needs to know so much through the flashbacks. It is what it is and I'm giving the book 4 stars because it's a great plot and as well written as Deborah Crombie's best mysteries. And thanks for the maps. They're part of the attraction of these books to someone who's never been there.