Scene Idea: Phone Call

I had the idea of a scene in which the main protagonist is asleep on the sofa. Then, the phone rings causing her to wake up and rush over to it in hope that it's her sister. When she answers, no-one speaks for a moment, then someone speaks and says "Kitty Kat, Kitty Kat, what will you do to get your sister back?".

This scene will establish the narratives disequilibrium. The effect of it will increase the trailers tension, grab the interest of the audience and also allow the films narrative to make sense.