Somebody built a goddamn school gym directly over the stolen cash his girlfriend buried for him.

And now, ex-con Zeki Müller has no choice but to pass himself off as a substitute teacher at Goethe Comprehensive School, thus providing the German educational system with one more problem, i.e. the craziest teacher of all time.

At night, Zeki digs secretly for his loot: during the day, he uses drastic yet effective methods to bring the unruly kids of class 10B back on track.