In an abandoned mansion at the heart of Barcelona, a young man, David Martin, makes his living by writing sensationalist novels under a pseudonym. Close to despair, he receives a letter from a reclusive French editor, Andreas Corelli, who makes him the offer of a lifetime -- write a book unlike anything that has ever existed -- a book with the power to change hearts and minds. In return, he will receive a fortune, and perhaps more. But as David begins the work, he realizes that there is a connection between his haunting book and the shadows that surround his home.