No one in the boring neighbourhood knows that Sabrina Parslowe, the new girl in town, is really Princess Sabrina of the House of Valence, living undercover to keep her blue-blooded identity a secret. A school trip to a museum promises to be a welcome escape from Sabrina’s big fat lie of a life. But when the museum tour begins, Sabrina’s worst fears are realised: There’s an exhibition on royal families! In one long, breathless race around the museum, the secret princess must call upon her devious Uncle Ernie, her friend Charlie and even the school bully, Awful Agatha, to keep everyone away from the shocking truth. Will Sabrina be exposed for who she really is?