Seamus Snow is a perfectly normal fifteen year old boy. Well, he's got a few quirks, but who doesn't? That is, until his twin sister, Mariah, finds a diamond in their backyard that might not be exactly normal. In fact, Seamus has this crazy idea that it's magical. An idea that is pretty much confirmed when he and Mariah are transported to a whole different world...a world where they have to rely on a sarcastic...and possibly sadistic...teenage girl to get them home. If they can get home.