Books like The Mark of the Dragonfly

Piper has never seen the Mark of the Dragonfly until she finds the girl amid the wreckage of a caravan in the Meteor Fields. The girl doesn't remember a thing about her life, but the intricate tattoo on her arm is proof that she's from the Dragonfly Territories and that she's protected by the king. Which means a reward for Piper if she can get the girl home. The one sure way to the Territories is the 401, a great old beauty of a train. But a ticket costs more coin than Piper could make in a year. And stowing away is a difficult prospect--everyone knows that getting past the peculiar green-eyed boy who stands guard is nearly impossible. Life for Piper just turned dangerous. A little bit magical. And very exciting, if she can manage to survive the journey.