The shortest of the series, thus book focuses on Fermin and his back story, which in Zafon's signature style, ties seamlessly into the tapestry that is The Cemetery of Lost Books. We learn about how Fermin became imprisoned with David Martin and the foreboding Salgado. We also learn where Mauricio Valls fits into the narrative.

The interconnectedness of these stories is impressive and Zafon's writing is a joy to read. A highly recommended series.