有谁会相信年仅十二岁的小菲利克斯把他们学校人见人恨的数学老师变成了身高仅有15厘米的小人?他不知道是怎么办到的,但这个举动却严重影响到了他们学校的生死存亡。他必须再把他的老师变回原来的大小,但是他该怎么做呢?在一系列的尝试与冒险中,菲利克斯变得越来越勇敢,越来越有担当。不仅在这次冒险中更加懂得了老师的良苦用心,也收获到了来自艾拉的友谊……The 11-year-old Felix has shrunk the hated school principal, Dr. Schmitt-Goessenwein, to a height of six inches. Together with his friend Ella, Felix has to get her back to her normal size, while his rival, Mario, tries to stop him. Otto Waalkes plays the ghost of the school's founder.