Will Smith‘s children Willow and Jaden Smith will co-star in an adaptation of the graphic novel Amulet: The Stonekeeper. Smith’s production company Overbrook Entertainment will co-produce for Warner Bros., according to Variety. The movie will tell the story of a brother and sister who use their late great-grandfather’s an amulet to rescue their widowed mother from an underground beast. Willow, 7, played a small role alongside her dad in the recent I Am Legend, and will next appear opposite Abigail Breslin in Kit Kittredge: An American Girl; while nine-year-old Jaden won several awards for his co-starring role opposite Will in The Pursuit of Happyness. The film is set to be released in 2010.