Lucas Corso, an authority on rare books, makes his living tracking down valuable items for rich bibliophiles. His latest assignment, deciphering the mystery of a 17th century book that legend has was co written by Satan, a book for which only three copies are known to exist, has become a very dangerous adventure. As if this weren t enough, a handwritten chapter of Alexandre Dumas The Three Musketeers comes into play. The stories intermingle and result in a page turning thriller distinctive of Perez Reverte s writing. The book was taken to the big screen in a movie titled The Ninth Gate by renowned director Roman Polanski.. Description in Spanish: Puede un libro ser investigado policialmente como si de un crimen se tratara? Lucas Corso, mercenario de la bibliofilia, cazador de libros por cuenta ajena, se enfrenta a esa pregunta cuando recibe un doble encargo de sus clientes: autentificar un manuscrito de Los tres mosqueteros y descifrar el enigma de un extrano libro, quemado en 1667 con el hombre que lo imprimio. La peligrosa indagacion le llevara de los archivos del Santo Oficio a los libros condenados, de las polvorientas librerias de viejo a las mas selectas bibliotecas de los coleccionistas internacionales.