ET is exclusively on the set of 'Twilight,' the vampire thriller based on the hugely popular, New York Times bestseller.

The movie, scheduled to hit theaters December 12, is directed by CATHERINE HARDWICKE ('Thirteen,' 'Lords of Dogtown') and stars newcomer KRISTEN STEWART, who plays mortal Bella Swan who falls for the dashing Edward Cullen (ROBERT PATTINSON) -- who just happens to be a vampire.