In 1942, an impulsive promise to her brother before he goes off to the European front puts Avis Montgomery in the unlikely position of head librarian in smalltown Maine. Though she has never been much of a reader, when wartime needs threaten to close the library, she invents a book club to keep its doors open. The women she convinces to attend the first meeting couldn't be more different—a wealthy spinster determined to aid the war effort, an exhausted mother looking for a fresh start, and a determined young war worker. At first, the struggles of the home front are all the club members have in common, but over time, the books they choose become more than an escape from the hardships of life and the fear of the U-boat battles that rage just past their shores. As the women face personal challenges and band together in the face of danger, they find they have more in common than they think. But when their growing friendships are tested by secrets of the past and present, they must decide whether depending on each other is worth the cost.