Jaiden, a 15-year-old farm boy, lives near Hilltop, a Medieval-type village and has never been more than a few miles beyond his home. He lives with his widower father who works the boy hard and treats Jaiden rather abusively. In this world, people have enslaved dragons as beasts of burden and as something like guard dogs and soldiers.
There are three kinds of dragons characterized by their various colors: gold (dog-sized) dragons trained to hunt and serve as guards; silver (about the size of a cow) trained to carry gold dragons on their backs and to serve as soldiers and hunters; and blue dragons (somewhat larger than an elephant) who are trained to tow Dragon Trains (powered by a low-flying dragon rather than a steam engine). The gold and silver dragons aren't very intelligent, but obedient to humans and easily trained. The blues however, are very intelligent and can communicate with each other telepathically although most humans are not aware of their ability to communicate. For many centuries dragons and humans were enemies, but in the last couple of generations, humans have become clever enough to overwhelm and enslave the dragons. But the blues long for freedom and escape from human control. Jaiden and Skye, an escaped blue dragon, encounter each other and a close, friendly relationship develops as the blue dragon with the young man's help escapes servitude towing a Dragon Train. The pair avoid capture while they are pursued through the forests and caves of the Emerald Forest. Eventually, they travel to Portville, a large city where the Dragon Train camps and training grounds are located.
But can the pair free her family and escape to a far northern land where dragons may live free?