Sewer dwelling spirit Baixo Astral is on a mission to bring unhappiness to the world, and his plans are threatened by Xuxa, who asks for children's help to make the world a better place. He declares war on her and devises a plan: helped by his allies Titica and Morcegão, he kidnaps Xuxo, her dog. Assisted by gypsy caterpillar Xixa and rebellious teen Rafa, Xuxa sets out to get her dog back and save the world from the wicked Baixo Astral.