Idea 1

Someone working in a lab, creating something, like some sort of chemical, the person who has made the chemical looks to have realised something, and with a tone of urgency, picks it up, and turns to leave, when there is someone behind her towering over him/her and he/she gasps. Cut down to the floor, a with the canera laying on the floor. Hear him/her scream, then see the chemical/test tube fall to the floor and smash.