Amulet is a graphic novel that focuses on a brother and sister who move into their late great-grandfather's house with their mother after their father dies. It's not a particularly safe move, because they have to "use his amulet to rescue their widowed mother from a beast who lures her into an underground world."
Should this adaptation be successful, I'd get ready to see a lot more of the Smith offspring. This could, potentially, be a series of kiddie adventures, since it's a Scholastic series with 5 books planned (#2 will be released this year). Personally, I'm glad to see a new children's adaptation that doesn't seem to be jumping on the boy wizard bandwagon. And really, how can you resist those tykes?