Sarah Smith 
The Knowledge of Water [EPUB ebook] 

“I will marry you, ” Perdita Halley said to Alexander von Reisden at eighteen, “but not until I study music.” Now, at twenty-one, she has come to Paris, his city–but music still stands between them. She is pursuing her dream of becoming a concert pianist; he is trying for the less likely one of becoming an ordinary, unhaunted man. They are drawn into an all-consuming passion that seems destined for tragedy. Perdita cannot marry and attend the Conservatoire; Alexander, still haunted by his past, fears to marry at all.
As incessant rain dims the City of Lights, an intricate network of plots and counterplots swirls around the couple. And an elegant game of art and life turns deadly, as a madman follows them, threatening to destroy them both in retribution for a murder they know nothing about–
Or do they?

A New York Times Notable Book of the Year.