In ancient Greek drama, the prologos (a word that means basically "speaking before") was the opening portion of the play, before the entry of the all-important chorus. It might be spoken by a single actor, maybe playing a god, who would "set the scene" for the audience. Playwrights today instead often provide the same kind of "scene-setting" information through dialogue near the play's beginning; in movies, it may appear (as in the "Star Wars" series) in the form of actual written text. In a nonfiction book, the lead-in is now usually called a preface or introduction; novels rarely provide any introduction at all. Still, prologue remains a useful word for nonliterary purposes. The saying "The past is prologue" tells us that, in real life, almost everything can be a prologue to what follows it.