Wayward Sadie leads her friends to the murals of the painter Mistral. There, they are transported to a star where their Halloween costumes become real. As Fortuneteller, Sadie only has to look in her crystal ball to help the others with their dream identities. Her friend Candy has become the Homecoming Queen. Her brother is a zebra and the neighbor boy is a musician in the star band. Other children in Sadie's grade school make up a bizarre community of star people who have also become enchanted. The hunt for a star-of-sapphire necklace takes up the latter chapters of this madcap fantasy.