When the most important friend in her life seems to have disappeared without a trace, Elena Greco, a now elderly woman immersed in a house full of books, turns on her computer and starts writing the story of their friendship. She met Raffaella Cerullo, whom she has always called Lila, in the first year of primary school in 1950. Set in a dangerous and fascinating Naples, their story begins and goes on to cover over 60 years of their lives as she tries to describe the mystery of Lila, Elena's brilliant friend and - in a way - her best friend, and her worst enemy.