What would happen if a Monster High’s girls were ghosts? What would happen if the girls crossed into another world? A haunted world where there are many secrets. The most spectacular adventure ever lived in Monster High is about to begin, a spooky, funny and mysterious story. Along with Monster High there is a secret: an invisible school called Haunted High, where are the different types of ghosts. Both worlds must unite and in this film will meet the ghosts monsters with the Monster High’s girls. River Styxx, daughter of the skeleton ghost, will take the girls from Monster High on the yacht that unites the real world of ghost world; in that moment all girls will enter the new school: to Haunted High.