HELP, I Shrunk My Parents (HILFE, ich hab meine Eltern geschrumpft)

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 hated and long-since dead Director Hulda Stingbeard. A coincidence causes the former shrunken and skeletonized school principle to rise again. When she manages to return to real life she almost defeats Otto Leonhard, manages to shrink Dr. Schmitt-Gössenwein and Felix' parents, and takes over the school. It takes Felix, Ella and their gang to set the levers in motion to save the school and bring Dr. Schmitt-Gössenwein and his parents back to their original size again.