Idea For My Trailer

I have decided that I'm going to link the trailer to something all teenage girls have experienced. I have decided that it will be a good idea to focus the story around the game 'bloody mary'. Where if you say the name 'bloody mary' in front of the mirror 7 times, she will appear and haunt you. I could do it so that a group of teenage girls play the game as a joke, acting as if they aren't scared and are really brave. The girl a mentioned in my narrative could take part, but however when she does it, it comes true and no one believes her.