Messenger of Truth by Jacqueline Winspear

This is one of a series of books starring Maisie Dobbs. Maisie is a young, independent private investigator. What is amazing is that this takes place in the 1930's. In this book Maisie is investigating the death of a man who was the twin brother of one of Maisie's friends from college. These books are in the style of Agatha Christie. No CSI, no DNA no cell phones, no videos - well, you get the picture! She has to use her intuition and her brain. That is the fun part. Winspear also does a wonderful job of describing the era in terms of the cultural, social and political atmosphere of the decade.