The talented young entrepreneur Finn Sieveking has to cope with the death of his mother Maria, who was always at his side in the management of the traditional Hamburg family business. Out of nowhere the adventurer Jonathan Clark appears, who introduces himself as his biological father. Finn has to cooperate with him unwillingly, because Maria has bequeathed both of them half of their business shares. Only gradually does Finn begin to understand what his clever mother intended.
Summer in Germany, anno 1970. Italy is the number one destination. As every year, swarms of Teutonic tourists make their way to the Adriatic Sea. Only Willi Hirsekorn (Heinz Erhardt) from Castrop-Rauxel has so far no plans to break south. That changes, however, as the bitchy neighbor Mizzi Buntje (Kate Jaenicke) proudly tells of their upcoming holiday in Italy. Willi can not afford this boasting. Shortly determined, the bags are packed, and already rushes Willi in the car with his wife Sieglinde, daughter Lotti and son Kuno the sun.