The Boundless, the greatest train ever built, is on its maiden voyage across the country, and first-class passenger Will Everett is about to embark on the adventure of his life

When Will ends up in possession of the key to a train car containing priceless treasures, he becomes the target of sinister figures from his past.

In order to survive, Will must join a traveling circus, enlisting the aid of Mr. Dorian, the ringmaster and leader of the troupe, and Maren, a girl his age who is an expert escape artist. With villains fast on their heels, can Will and Maren reach Will's...