The Wizards of Once is the first book in a children's fantasy series by Cressida Cowell, the author of How to Train Your Dragon. The story is set in a magical, ancient Britain where magic and iron are fiercely opposed. The protagonists are Xar, a young Wizard prince who desperately wants magic, and Wish, a young Warrior girl who secretly possesses a magical object. They are destined to be enemies, but they must unite against a growing dark power. The book is an epic tale of magic, destiny, and unlikely friendship.