Seppi could really be satisfied. His arch-enemy Kevin has now become an ally. Together with Hansi and Merlin, the four consider themselves unbeatable. If it weren't for Schacke-Line and other annoyances. When a project day on the theme of the Middle Ages is announced, the four students sense their chance. In their headquarters, they come up with the biggest ideas ever conceived by students. It's only natural that not everything goes smoothly. In the third part of the hit series, Seppi and Co. are once again out of control.