Mile, Pauline, Reina, and Mavis face off against the chief of the elder dragons in a battle that will test the limits of their power. It's up to the Crimson Vow to decide whether war breaks out between dragonkind and humans. But even if the girls emerge unscathed, there's war of another kind on the horizon--a war between the Crimson Vow and the Wonder Trio, over Mile!