What are dreams and why do we have them? NOVA joins leading dream researchers as they embark on a variety of neurological and psychological experiments to investigate the world of sleep and dreams. Delving deep into the thoughts and brains of a variety of dreamers, scientists are asking important questions about the purpose of this mysterious realm we escape to at night. Do dreams allow us to get a good night's sleep? Do they improve memory? Do they allow us to be more creative? Can they solve our problems or even help us survive the hazards of everyday life?