Saint-Malo, France: August 1939. Jocelyn and Antoine are childhood sweethearts, but just after they marry, Antoine is drafted to fight against Germany. As World War II rages, Jocelyn uses her position as a librarian in her town of Saint-Malo to comfort and encourage her community with books. Jocelyn begins to write secret letters smuggled to a famous Parisian author, telling her story in the hope that it will someday reach the outside world.
France falls and the Nazis occupy Jocelyn's town, turning it into a fortress. The townspeople try passive resistance, but the German commander ruthlessly begins to destroy part of the city's libraries. Books deemed unsuitable by the Nazis are burnt or stolen, and priceless knowledge is lost.
Risking arrest and even her life, Jocelyn manages to hide some of the books while desperately waiting to receive news from her husband Antoine, now a prisoner in a German camp.
Jocelyn's mission unfolds in her letters: to protect the people of Saint-Malo and the books they hold so dear. Mario Escobar brings to life the occupied city in sweeping and romantic prose, re-creating the history of those who sacrificed all to care for the people they loved.