History & Mystery discussion

My favorite books are those that are set in a historical period but the mystery is not necessarily a crime and does not involve a detective (hobbyist, private or from the criminal justice system) but where an individual is confronted with a mystery to solve in their life. An excellent example is A Very Long Engagement. If any members of the group have other examples I would be interested. I am now reading one of these type of books. It is Stella Bain. It has been a while since I have read an Anita Shreve novel. This does seem to be an intriguing subject and is set during WWI.