Lucas Corso, mercenary fighter and bibliophile books, receives from the dual mission of clients to authenticate a manuscript chapter of the Three Musketeers and decipher the riddle of a strange book, The nine gates of the kingdom of shadows, burned in 1666, together with its author, on the orders of the Holy Office. This is laid, in the words of the text of the back cover, as part of this story that will lead the main character from Toledo to Paris, passing by Portugal. Corso will experience a journey full of obstacles and pitfalls, be faced with other characters he will have all the trouble in the world to recognize in them friends or enemies, and to top it off, grapple with a challenge deem it increasingly opaque and insurmountable. This is undeniably a novel of adventure, full of action but also an introductory book on book collecting together as demonology. Indeed, rare books looking embarked Corso which are neither more nor less than initiatory and esoteric books which contain a ritual to summon the Devil. Club Dumas is also a great cultural monument dedicated to the bibliophile. Either Pérez-Reverte is a knowledgeable bibliophile which case its cultivation in this area is quite impressive, or he led an enormous documentation work, or else it has an unconventional inventiveness as planks reproduced in the novel as the references seem larger than life. Only drawback: the data and considerations bibliophile order are somewhat invasive. Even if they are at the heart of the plot, they would have benefited from being less important to be more digestible and avoid undue reading. However, I went with great interest to the end of this exciting novel whose denouement is the image of the book: surprising and unexpected. A good read that I would not hesitate to recommend.