Maud's beloved Rotwood, a secret school for monsters, is under a cloud ... literally! The pupils' monstrous games and spooky spells are filling the area with noise and smoke. Local residents are fed up and the school is facing closure! Maud and her friends are determined to help the Head, but end up accidentally terrifying the inspector during a crucial inspection. Was it an accident, though? Maud suspects foul play and thinks one of the teachers, a nasty warlock, might be behind a pernicious plot to shut the school down. Can Maud uncover the wicked warlock's plans and save her school?