Portia & Frederick

Some children run away from home to join the circus. This isn't a book about that. So if that's what you had in mind you should look elsewhere. But if on the other hand you're looking for a book about a girl and her brother who run away from home and on their way come across formidable nuns, bloodthirsty pirates, tricky politicians, and gung-ho soldiers, well then you might have found just the thing.