The things we cherished - Pam Jenoff

Roger Dykmans, a university student, is living with his brother Hans, an international emissary who's secretly working against the Nazis. As time goes by, Roger finds himself increasingly drawn to Magda, Hans' Jewish wife. But their secret world is turned upside down when Magda and her young daughter, Anna, are arrested by the Nazis. The Gestapo make a deal with Roger: if he hands over information about Hans' operations, they'll set Magda and Anna free. Suddenly, Roger is faced with an impossible decision: should he betray his brother to save the woman they both love?

Spanning decades and continents, The Things We Cherished explores the strength of true love under the worst of circumstances.