Bank robber Zeki Müller has just been out of prison. Upon his release, he goes to retrieve the money he stole in order to repay a debt, but his friend buried it in a construction site. During Zeki's time in prison, the construction project was completed and his money is now buried beneath the new gymnasium at the Goethe Gesamtschule. In order to obtain the money, Zeki applies for the vacant position of a deceased janitor. However, due to a misunderstanding, he is given a job as a substitute teacher.