Kate Mosse 
Citadel 

An epic wartime novel from the No.1 bestselling author of LABYRINTH and THE CITY OF TEARS1942, Nazi-occupied France. Sandrine, a spirited and courageous nineteen-year-old, finds herself drawn into a Resistance group in Carcassonne – codenamed 'Citadel’ – made up of ordinary women who are prepared to risk everything for what is right.And when she meets Raoul, they discover a shared passion for the cause, for their homeland, and for each other. But in a world where the enemy now lies in every shadow – where neighbour informs on neighbour; where friends disappear without warning and often without trace – love can demand the highest price of all…