Under Guardian William's rule, the people of Alsace huddle in castles, dreading the next attack of the Gemstone Wyverns. As Josh Wyrmherd admires a large uncut diamond, which awaits the next king to claim it, a wyvern crashes through the window and steals it from the castle.
Guardian William's Heir, accuses Josh of assisting the wyvern, and he's exiled from the kingdom. Having witnessed what really happened, Josh's schoolmate Alyson exiles herself with him in spite of his objections. Together they make their way to the mountaintop eyrie where thousands of wyverns nest, including the one who stole the uncut diamond, Queen Aria. Injured in her escape, she asks Josh for help.
After he removes the spearpoint from her flank, Josh learns that humans and wyverns haven't always lived apart. She gives him the diamond, making him the next King of Alsace. But to become king, he'll have to depose Guardian William Kingstead, whose family has ruled Alsace for hundreds of years. With Alyson at his side, Josh embarks on a journey that will change their lives and shape the future of the whole kingdom.