Fifteen-year-old Klaus "Kurbel" Kambo already thinks of himself as an adult: he is big, strong, can hold a lot of rhubarb wine and has already kissed a girl. But being mature is a lot more difficult than he thinks, as he realizes when he struggles to own up to the fact that his new method of lawn mowing caused a wild fire in the forest. Fortunately, Klaus is able to build relationships with the teacher Konzak and the construction worker Jule, whose understanding and support help him to start to really grow up.

Based on the novel The Giant in Paradise by Joachim Novotny.