Twenty-five-year-old Mel Parker has a few tiny problems: Her job is terrible. She's been dumped yet again. Her ex is now her boss. The one good thing in her life has always been her best friend, Will, who has seen her through every crisis from lost toys to pregnancy scares. But his girlfriend (who's prettier, better-dressed, more successful, and secretly evil) is determined to replace Mel as the woman in his life, and how is Mel supposed to compete?