GK isn't saying what the movie's about — just that it's a sci-fi thriller set in the Australian outback and that Ross and Nissar Modi came up with the idea. Modi is writing the script.
Tobey Maguire, Ross, Graham King and King's GK Films' Tim Headington are producing.
Mulligan starred as Kitty Bennet in the 2005 "Pride and Prejudice," and has worked steadily since. She's attached to play Daisy Buchanan in Baz Luhrmann's "The Great Gatsby, now in preproduction.
Variety first reported the news.