Pluft shows the unexpected friendship between the ghost who is scared to death of people and the girl Maribel. She is kidnapped by the pirate Perna de Pau, who wants to use her to find the treasure left by her grandfather, the late Captain Bonança Rainbow. In the abandoned house where the old man lived, Maribel waits for the help of the sailors Sebastião, João and Julião, very friends of the old captain, who go out on a clumsy search for the girl.