The author discusses the role of a book in detective and fantastic fiction. Real or invented books provide an opportunity to reveal the plot. With the help of them the authors create new worlds. The book is considered as a subject with great importance and strength, it becomes one of the main elements of the narrative. With the help of a book, the writer gives the reader information about heroes and events. But in describing “dangerous books”, some authors express disappointment in the creative power of knowledge, the carrier of which is a book. Through the book, evil forces can invade the world of people, disrupting the usual way of life. “Ancient” magic books symbolize the fear of a modern civilized person who is afraid of the archaic.