This document discusses narrative conventions and structures in horror movie trailers, specifically those involving vampires. It notes that vampire movies often use non-linear narratives through techniques like flashbacks and flash-forwards to build tension. Trailers for these types of movies typically do not reveal the full storyline or clearly define which characters are heroes or villains, leaving audiences with enigmas that intrigue them and make them want to watch the full film. The goal is to draw in viewers without giving away all the key plot details.