This document discusses several narrative theories and how they apply to teaser trailers. It explains Tzvetan Todorov's theory of narrative structure, which involves an initial equilibrium that is disrupted by an event causing disequilibrium, which is then resolved with a new equilibrium. It notes how teaser trailers show the initial equilibrium and disequilibrium stages. It also summarizes Roland Barthes' narrative codes, including the hermeneutic code involving mysteries and the proairetic code involving actions. Finally, it discusses Claude Levi-Strauss' theory of binary oppositions reflecting cultural values and how this can be seen in teaser trailers.