Summit Entertainment aims to start production on the fourth installment of the Twilight Saga this fall in Vancouver. The studio will most likely adapt Breaking Dawn, the final book in Stephenie Meyer’s  bestselling vampire series, as two separate films. Actors Robert Pattinson, Kristen Stewart, and Taylor Lautner are once again set to star.

Contrary to web rumors, however, New Moon director Chris Weitz is not attached to direct.

Producer Wyck Godfrey tells the LA Times:

It’s a work in process. The issue [of whether there will be one or two movies] is not going to be resolved until we get the full treatment and see whether it’s organic. If it’s not organic, I don’t think it will be done, and if it is, it will be. It really has to do with how much level of detail from the books there is, with all of these new vampires that appear in ‘Breaking Dawn,’ the whole section about Jacob… It’s a very long single movie if it does become a single movie.

Right now, we’re just focused on the treatment and getting that right. At that point, we’re going to see who’s available and who’s appropriate. It’s such a complicated book because you have the emotions and the intensity of the love story — so you need somebody who’s just a wonderful director of actors — and yet it’s really complicated from an action and visual effects standpoint. They’ve got to have both tools in their kit.

Meyer’s “Breaking Dawn” novel set a first day sales record upon its release in 2008 and went on to dominate the charts for multiple weeks. Reviews for the book from both critics and “Twi-Hards” were mixed.

Eclipse, the third chapter in the Twilight Saga, is directed by David Slade (30 Days of Night) and  arrives in theaters on June 30.