I just finished The Villa: A Novel, by New York Times best selling author Rachael Hawkins. This mystery is really two stories wound into one. And if you know anything about Mary and Percy Shelley and the summer they spent at Lake Geneva with Lord Byron (yes, the summer that she wrote Frankenstein), you will see that this story is inspired by them - as well as some of the famous murders of the 1970s.
Amazon has this listed as a best selling mystery, and I can see their point. I got my copy at the library - knew nothing and was pleasantly surprised. I might say that it is not the best mystery that I have ever read, but it’s a good story. Fast read. Yes I recommend!