Complex sentence: Donna and her boyfriend, Scott, see a frightened Carol Anne running through the high rise's parking lot, and move to rescue her; however, before they can, all three are taken to the Other Side by Kane.
Split into simpler sentences: Donna and her boyfriend, Scott, see a frightened Carol Anne running through the high rise's parking lot, and move to rescue her. However, before they can, all three are taken to the Other Side by Kane.