Actress Saoirse Ronan plays Melanie Stryder in the movie adaptation of Stephenie Meyer's novel The Host.

(Photo credit: Reuters)

Filming is underway for the movie adaptation of author Stephenie Meyer's book The Host, and the first trailer is scheduled to debut on Thursday.

The trailer will debut on television on Access Hollywood and online via Yahoo! Movies, the author said on her website.

The movie's director, Andrew Niccol (In Time, Gattaca), spoke with People magazine about the film, which hits theaters on March 29, 2013.

It's kind of an alien love story, he told the magazine.

Meyer's story, which is described on her website as Science fiction for people who don't like science fiction, is about a young woman named Melanie Stryder, played by Saoirse Ronan (Atonement, The Lovely Bones), whose body is taken over by a member of an alien race called Souls. Stryder and her body's new inhabitant are each in love with a different guy, which is just part of their problems.

Meyer gushed about members of The Host cast at the premiere for Breaking Dawn Part One.

So amazing, Meyer told MTV of Ronan. You just can't take your eyes off her. She's unbelievable. I'm so excited to see her career from here on out. 

Ronan's love interests in the film will be played by actors Max Irons (Red Riding Hood) and Jake Abel (I Am Number Four, Supernatural), and it looks as if the onscreen chemistry between the couples is going to be electric.

Cut it with a knife, Meyer said. It was just great. 

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