The document summarizes two narrative theories - Vladimir Propp's theory of character types and plot events in folktales, and Claude Levi-Strauss's theory of binary oppositions in narrative. It then explains how an opening sequence for a teen horror genre film draws from both theories, using character types like the villain and hero, and establishing binary oppositions of good vs evil. Roland Barthes' theory of media using mystery and questions to engage audiences is also mentioned as relevant to revealing the killer's identity in teen horror films.