Will Ferrell stars as Harold Crick, a lonely tax agent whose world is turned upside-down when he starts hearing a mysterious voice narrating his life. With the help of professor Jules Hilbert (Dustin Hoffman), the bewildered and hilariously resistant Harold discovers he's the main character in a novel and that the voice belongs to Karen Eiffel (Emma Thompson), an eccentric author famous for killing off her characters in creative ways. Finding unexpected comfort in an unlikely romance with a tax client (Maggie Gylienhaal), Harold goes in search of Eiffel in a bid to stop her before she conjures up a way to finish him off.