The movie follows a man's search for perfection in a world where life rarely measures up to the idealized images that constantly bombard us. Gary Shaller (Martin Freeman), who gained commercial success in previous years as the keyboard player in the fictional band "On The One" is in a failing marriage with Dora (Gwyneth Paltrow), and working for his former band mate Paul (Simon Pegg), writing and recording commercial jingles. Gary eventually discovers that he is having lucid dreaming about a glamorous woman named Anna (Penélope Cruz), with whom he is deeply infatuated. He aims to learn more about lucid dreaming by buying books and even attending classes taught by an eccentric lucid-dreaming enthusiast, Mel (Danny DeVito).