Sam and Amelia McDonald cannot imagine a more disastrous turn of events than their father's upcoming marriage to Lillian Ledbetter, but when Sam is snatched from his bed in the middle of the night and a wee, loudmouthed fairy crash lands in Amelia's room, the wedding becomes the least of the McDonald children's worries.
Deep in the fairy Kingdom of the Moon, fourteen-year-old Sam wakes in the home of Idgit, a bespectacled gnome eager to tutor Sam in fairy history. Mercifully, Idgit's mischievous son steps in to be Sam's guide and guru. As Sam begins exploring the not-so-benign world into which he has been thrust, he begins to wonder if he can live long enough to figure out why he is there.
Disguised as a fairy, Amelia journeys into the Kingdom of the Moon to find Sam with the help of the impetuous fairy Morta. Not only must Amelia master the art of flying, she has to contend with malevolent fairies, hungry sea serpents and the lack of chocolate in the local diet if she hopes to be reunited with her older brother.
As Sam and Amelia struggle to discover their link to the world of fairies, they come to suspect their presence in this world has sinister implications: someone is plotting against the Kingdom of the Moon, someone who has taken a very unhealthy interest in the McDonald children.
Start with the basics: Sam finds himself in a place he never imagined existed: the land of the fairies. He has no idea why or how he got there. His sister wants to find him. Build from that and give us a sense of who "someone plotting" is.