In the tumultuous Madrid of the 1930s, provincial girl Tina dreams of becoming a librarian. Together with her friend Veya, she enters the world of cabarets, feminist clubs, and spiritual séances, but much more than the lively life of the capital, the girl is interested in the Invisible Library — a secret society that once saved books threatened by censorship. Tina is convinced that her calling is to save books. Working as a librarian in besieged Madrid under Franco, Tina realizes that not only the banned books need saving, but all books, as the war is being fought on the book front — history is being rewritten, facts are replaced by fabrications, and ideology displaces humanity.
But even in the epicenter of devastating war, life goes on; Tina finds her love, yet nothing will stop her from continuing to defend books, not only from fires and bombs but also from ignorance and barbarism. A grand novel about the love of books, about how to maintain human dignity even in an atmosphere of fear and total persecution.