In more than half of Truffaut’s films, characters write novels about their own lives, while nearly every second film is adapted from a literary work. Why was a director who revolutionised the language of cinema so obsessed with books? Why do children in his films behave like adults, women like men, and men like children? And why did Steven Spielberg choose François Truffaut to play the professor who deciphers the language of aliens in Close Encounters of the Third Kind?