Bank robber Zeki has a problem, the catch from the latest robbery is buried in a place where there is now a school gym. To gain access to the school’s basement and from there dig a tunnel, he is forced to take a job as a substitute teacher.   Somebody built a damn 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.