Twelve year old siblings Karina and Charlie Rosas aren't looking forward to vacationing with their estranged uncle. But when the Fernweh Express derails and tosses them into a wild, unrecognizable land, they trust he'll know what to do. After all, Diego Rosas wrote the book on survival in deserts and arctic tundras. There's nothing he can't handle . . . until a colossal, fire-breathing dragon snatches him up and carries him away, leaving the twins to embark on an impossible rescue mission.

With the natural elements working against them, the Rosas family adventures through the curse-infested, uncharted world in order to solve the mystery of what doomed their travels. When they meet up with a dwarf and a pirate queen who offer aid, Karina and Charlie must decide whether they can trust anyone willing to voyage into a dragon's den. But if the siblings ever want to return home, they must trust and lean on each other, and above all, hope Uncle Diego is still alive.