One more 'Once upon a time...' No one knows the hero business like Hawk and Fisher. That's why they started the Hawk and Fisher Memorial Academy—to share their skills with the next generation of heroes. Decades later, their Hero Academy is the Dutchy of Lancre's most profitable tourist attraction, its greatest pride, and now...its biggest problem. During auditions for the next class of students, an assassin ambushes Hawk and Fisher, setting off a powerful chain of events that could destroy the Forest Kingdom. For the Blue Moon rises once more, and with it, a familiar and formidable foe that Hawk and Fisher thought they'd never see again—the Demon Prince. Now, Hawk and Fisher must embark on one final quest. Joining forces with their children, they'll reunite with old friends, visit legendary lands, and battle infamous villains to stop the Demon Prince once and for all. Hanging in the balance is the future of their bloodline, the kingdom, and the world. Once in a Blue Moon is the compelling conclusion to New York Times bestselling author Simon R. Green's beloved The Forest Kingdom series.