A Nightmare On Elm Street Trailer (1984)

the film's premise is the question of where the line between dreams and reality lies. The villain, Freddy Krueger, thus exists in the "dream world" yet can kill in the "real world". Sequels to the original would continue to blur the distinction between dream and reality before finally challenging the line between film and reality by showing Heather Langenkamp, playing a fictionalized version of herself, haunted by the villain of a series of films she has starred in.