1929: Marie Lehning, a farm worker from Warmsdorf on the Baltic Sea, falls in love with the fisherman's son Mingo. Both complete an apprenticeship in Lübeck. Marie wants to become a seamstress, Mingo a carpenter. After their first night of love, they swear eternal fidelity. But Marie has to return to the village, her mother is ill and her siblings are unprovided for. She starts working as a maid on a farm. Unexpectedly, she meets the young Kurt Meier from Berlin, whom she knows from before.

The clever but poor farmer Klaus infuriates the rich big Klaus with his mischief. But little Klaus always manages to get out of the most difficult situations and emerge victorious in the end. But one day, big Klaus has a fit and wants to drown little Klaus. Now he once again has to rely on his intuition and his wit ...

After a fierce argument Steffi Zinn′s husband leaves the joint flat and stays away from home over night. The next morning, his wife Steffi has disappeared and is reported as a missing person. Captain Lohm takes over the case and at first looks for signs of a murder, but to no avail. Then, Steffi′s body is found in a lake. After her funeral, a stranger who had attended Steffi′s funeral for a short time is also found dead in a lake, and the connection between the two cases becomes apparent.