The film centers on a vain young women (Mulligan) who is bitter after she fails to escape the confines of her small-town life. In an attempt to win the affection of her high school crush, she sets up a get-rich-quick scheme-stringing along an unlucky man in the process-that fails.
"Nancy and Danny" was written by Brad Inglesby, who penned the touching family drama "The Dynamiter" in 2011. James Marsh, who won an Oscar for his documentary "Man on a Wire," is set to direct.
Mulligan gave two standout performances last year. She appeared in "Drive" as a struggling mother who befriends a lonesome Ryan Gosling and played Michael Fassbender's troubled sister in the controversial "Shame."
The actress first wowed audiences in the 2009 drama "An Education" as a naïve high school student who falls in love with an older man.
In March, Britain's Women in Film and TV named Mulligan one of the "Top 50 Female British Power Players." The 27-year-old will soon be seen in "Inside Llewyn Davis." Directed by the Coen Brothers, the film explores the folk music scene in the 1960's. Justin Timberlake and John Goodman costar in the film, which is scheduled to open in December.
Mulligan will also star opposite Leonardo Dicaprio in Baz Luhrmann's 3D adaptation of "The Great Gatsby." Though the film was initially slated for a Christmas 2012 release, it has been pushed back to the summer of 2013.
On April 21, the British born actress married "Mumford and Sons" lead singer Marcus Mumford in Somerset, England.