10 Movie Trailers That Don't Spoil ANYTHING

Alfred Hitchcock was so blown away by Robert Bloch's novel, Psycho, he adapted the story for the big screen as soon as possible. However, Hitchcock wanted his audience to feel the same shock and horror he experienced when he read the book. To ensure nothing about the story leaked, Hitchcock bought every copy of Bloch's novel that he could find. On the first day of filming, he ordered the cast and crew to swear an oath not to divulge anything about the project.

Despite these precautions, it still wasn't enough. For the trailer, Hitchcock decided not to show a single frame from the movie. Instead, this six-and-a-half minute long teaser has Hitchcock discussing the grisly nature of his upcoming picture.

He cryptically references a seemingly innocuous painting and implies the toilet harbours a clue but gives nothing away. Even though the promo displays no gore, the film's violence is regularly implied by Hitchcock's off-the-cuff remarks like, "Boy, they cleaned this up too... big difference."

It was an excellent way to tantalise the audience without giving a single detail away. It worked out since Psycho went on to be Hitchcock's most successful film ever.