The Experimentalist by Nick Salaman
Marie is a child with a dark past - a secret family history that her guardian protects her from. She's not sure what the dark secret is: was her father a criminal, a Nazi, both? Unpleasant lawyer Brickville seems to hold all the cards, until she meets a kindly American, Felix Middleberg. When her life takes a turn for the worse, he steps in to look after her. But he knows more about her than he should and exercises a control she finds oppressive. Where does his wealth come from? What has happened to her family? Who, in fact, is Marie? And can she ever escape her protectors?