In the midst of her dull, uninteresting life, Kate's 11th birthday is shaping up to be mundane—until her mysterious Uncle Herbert, whom she's never even met before, surprises her with the most exhilarating, inappropriate birthday present of all time: a colossal steam locomotive called the Silver Arrow. In this novel for readers 9 to 12 by the author of the Magicians Trilogy, Kate and her brother Tom are soon riding magical rail lines for distant lands in the company of an assortment of talking animals. With only curiosity to guide them, Kate and Tom are on the adventure of a lifetime, but they will need to be ready when they are called upon to save the world.