HOW TO FILM A SECRET is an essay film that mixes documentary and fiction to present the journey of first-time director Dionéia Fernandes in the process of learning about cinema while trying to tell her own story. At the age of 65, she decides to investigate a doubt that hangs over her origins: is she really her parents' biological daughter? Born as a twin, Dionéia shares with her sister a common reality in a Brazil still submissive to patriarchal culture - an upbringing in which being a woman is not only a difficulty, but also a "failure". Prevented from studying in her youth, it is now in her old age that she decides to use cinema as a tool to think about identity. If who we are is a story - who is the narrator of our lives?