Book One follows Tulip, a headstrong 13-year-old girl, who must use her wits to uncover the train's many secrets - and hopefully return home. Tulip's mind-bending journey will find her forging friendships with One-One, a robot with dueling personalities, and Atticus, the canine king of Corginia. But with new surprises awaiting in every car, will Tulip ever find a way off the train?