Palmer will play the role of Number Six. She is one of nine aliens who has escaped their home planet before it was annihilated by a rival species. They then come to Earth disguised as human high schoolers.
Alex Pettyfer is going to play the title role of Four. Sharlto Copley will be Alex Pettyfer's guardian and mentor.
Michael Bay is producing this project with Steven Spielberg. Al Gough and Miles Millar (Smallville) wrote the screenplay.