Rain Dogs

For my 1st award winning book for 2019, Edgar award for 2017 for Best Paperback Original! Takes place in Ireland in the 1980's (Had a bit of trouble with some of the Irish slang) and this is book 5 in a series of Detective Sean Duffy books! Woman found dead in a castle where there is no way in or out!!
How was it done and why!! Great mystery, Read the Book! David N