DNA is at the heart of the story, who is related to whom. Seems everyone is related to the Blackstocks to some degree, not a good thing to be as murder is stalking the family.
Personal relationships are written into the story too, as in real life we are all fallible at times. Characterisations are realistic.
Related to real life events such as the US airfields in Norfolk in WW2, & the floods of 2013, makes the story very believable.
There are some gruesome bits e.g. human bones found in the pig sty.
The addition of a bit of humour is always good, loved the motorised duck used to rescue people in the flood.
I would recommend this book, & all the others Elly Griffiths has written.
Reserve Ghost Fields