CHUD‘s got the scoop on a potential third Scooby Doo movie. According to screenwriter James Gunn, a possible focus of the movie might be “Scooby and Shaggy’s fear and how that affects their lives.” Apparently Matthew Lillard (Norville ‘Shaggy’ Rogers) and Linda Cardellini (Velma Dinkley) have signed for it already, but Sarah Michelle Gellar (Daphne Blake) and Freddie Prinze Jr. (Fred Jones) have not. Hmm, sounds like there’s a mystery that needs to be solved.