In Tarifa, Santiago meets an old man while sitting on a bench in the marketplace. At first, the old man annoys him. Then the old man reveals that he knows the names of everyone in Santiago's life, which catches Santiago's attention. The old man says he is a king, and his mysterious knowledge supports his claim. The old man tells Santiago the book he is reading, like almost all other books, contains the world’s greatest lie. What is this lie?

The old man tells Santiago that the world's greatest lie, which is contained in almost all books including the one Santiago is reading, is that "at a certain point in our lives, we lose control of what's happening to us, and our lives become controlled by fate."

According to the old man in the story, the greatest lie contained in almost all books, including the one Santiago is reading, is that "at a certain point in our lives, we lose control of what's happening to us and our lives become controlled by fate."