Ruiz shares the story of a person 3,000 years ago who was studying medicine but knew there must be more to life than what he was experiencing. The man falls asleep in a cave and dreams that he sees his physical body sleeping but is outside of it. He hears his voice say, “I am made of light; I am made of stars” (xvi). Looking at the stars, he realizes that light creates them, as opposed to stars creating light. He sees that everything—even the space between the stars—is made of light and that everything is part of one living being. He sees light as the messenger of life. He calls the stars tonal and the light between the stars nagual, and he sees Life—that one living being—as creating harmony among the stars and the light in between them.

The man realizes that everything is God and human perception is light perceiving light. He sees everything and everyone as a mirror reflecting light—and sees that a world of illusion exists like smoke between the mirrors, stopping them from reflecting light—and keeping humans from seeing who they are, which is pure love and pure light.