As a child, Daniel Sempere discovered among the passageways of the Cemetery of Forgotten Books an extraordinary novel that would change the course of his life. Now a young man in the Barcelona of the late 1950s, Daniel runs the Sempere & Sons bookshop and enjoys a seemingly fulfilling life with his loving wife and son. Yet the mystery surrounding the death of his mother continues to plague his soul despite the moving efforts of his wife Bea and his faithful friend Fermín to save him.

Just when Daniel believes he is close to solving this enigma, a conspiracy more sinister than he could have imagined spreads its tentacles from the hellish regime. That is when Alicia Gris appears, a soul born out of the nightmare of the war. She is the one who will lead Daniel to the edge of the abyss and reveal the secret history of his family, although at a terrifying price.