The movie starts with rare books-collector Frank Corso (Johnny Depp) getting a mission from publishing tycoon Boris Balkan (Frank Langella). Balkan has recently acquired a copy of The Nine Gates to the Kingdom of Shadows by 17th century author Aristide Torchia. The book details the summoning of the devil. Balkan is certain the book is a forgery. He wants Corso to find the other two known copies, find out whether any of them are genuine and - in that case - acquire them for Balkan.