Felix's school is haunted again, only this time it's not the benevolent spirit of school founder Otto Leonhard and the nuisance he caused, but the once hated and long-since dead Director Hulda Stingbeard. A coincidence causes the former shrunken and skeletonized school principle to rise again, leading to chaos...

Already having a hard time adjusting at his new school, things take a turn for the bizarre for eleven year old Felix when he accidentally shrinks his strict principal to only fifteen centimetres in height!

Melanie is a new pupil at the Otto Leonhard High School, and Felix takes a real shine to this newbie, much to the annoyance of Ella and Felix’s gang. They believe that Melanie is responsible for a number of small thefts that have been happening at the school since she arrived. Events take a drastic turn when the class goes on a school trip...