Hidden

During her first trip Outside her home kingdom of Cienna, eight-year-old Ruby meets a boy named Oscar who is nothing like the barbaric Outsiders she grew up hearing stories about. Intrigued by one another's stories, they agree to keep in touch via secret letters. But as they grow older, an undeniable truth becomes evident: Something is terribly wrong, and it's up to them to uncover the horrible secrets of Cienna's past. What they find is something neither of them could have ever dream of.