Often, as you first watch a movie, you think you see where the story is headed, but then there’s a plot twist. An effective device in promo/trailer editing is to follow the initial trajectory of the story while leaving out the plot twist. This makes for high drama but avoids spoilers. I used this for “Mommy Would Never Hurt You.” Although I lay out the dark storyline of the film, you’ll have to watch the movie to know how it really ends.