Barcelona, the 1950s, the dark days of General Franco's regime. One day the beautiful and intelligent agent Alicja Gris receives an order from the highest spheres of power. The case is strictly confidential and concerns the mysterious disappearance of Culture Minister Mauric Valls. It seems to have something to do with the past when Valls was the director of the appalling Montjuic prison. Alice and the police captain have a few days to find the minister. During her search, Valls's seventh volume of the series 'Labyrinth of ghosts' comes into her hands. This book will lead Alice to the Sempere i Sons bookstore, hidden in the heart of Barcelona. The charm of this place makes childhood images return to it as if through a fog. What she discovers can be a deadly threat to her and to everyone she loves.