Mirta continues her studies at Alfea, but it is very difficult for a former witch to become a fairy, and therefore she begins her studies from the first year. From Griffin she learns about the legendary planet Melancholia, which hides the secret of uniting the powers of witches and fairies. Before leaving for Melancholia, Myrta visits her old friend Lucy and discovers that she has been petrified. Someone has declared a witch hunt, and only Mirta and her friends can stop him.