The Nightingale, by Kristin Hannah

In Nazi-occupied France, two sisters, separated by circumstance, are forced on divergent paths and face unimaginable choices. Vianne, a spirited young woman who embraces life and love, finds herself in a passionate affair with a German officer. Meanwhile, her fiercely independent sister, Isabelle, joins the French Resistance and uses her sharp wit and courage to fight against the enemy. "The Nightingale" is a powerful and unforgettable story of love, loss, and the enduring strength of the human spirit in the face of war.