The Arsenic Labyrinth by Martin Edwards.
This is the third book in the Lake District Series. It has been 10 years since Emma Beswick disappeared. Hannah Scarlett and her cold case team reopen the investigation. The book also features Daniel Kind the Oxford Historian who has moved from the city life to live in the Lake District and Miranda, Daniel's girl friend who becomes increasingly unhappy in the Lake District and hankers after city life once more.
The arsenic labyrinth in Coniston is a place where arsenic a byproduct of copper mining was once proccessed deep underground.A great place for the murder victims to have been buried for a long time.
Themes are the rise and fall of family fortunes, murder, greed, dishonesty and gambling adiction to name a few.
There are a whole load of twist and turns to keep the reader on edge. Lots of amazing characterisation. The reader learns of the mystery of the connections with the Clough and Inchmore families. There are quite a few more complicated relationships within the story which all add to the suspense and uncertainty. I never guessed who did it until the very end.
Great to meet up again with some of the characters from the previous books. This is excellent British crime fiction at its best, skillfully written by Martin Edwards.
I look forward to reading the rest of the series