Paris, 1939. When World War II breaks out, Odile Souchet stands to lose everything she holds dear - including her beloved library. But by war's end, Odile tastes the bitter sting of unspeakable betrayal. Montana, 1983. Odile's solitary existence in gossipy small-town Montana is unexpectedly interrupted by her neighbour Lily, a lonely teenager craving adventure. Odile helps Lily navigate the troubled waters of adolescence, never suspecting that Lily will be the one to help her reckon with her own terrible secret. Based on the true story of the American Library in Paris.