Before the police station in Ober-Himmelbrunn is dissolved, the local landlord reports a burglary. The young gendarme Thaler is assigned to solve the case. Disguised as a holidaymaker, he goes to work. In the process, he conquers the hearts of twelve attractive girls who want to spend their holidays in an alpine hut.
In spite of his blustering manner and his refusal to listen to what the patients have to say, Dr. Doppelsieder is highly respected in the Upper Bavarian town of Bayrischzell, because he (almost) always has the right remedy and effective advice ready for the sick. The only person he can't help is Pfundtner, the rich Guldenhof farmer. He wants a remedy that, after seven daughters, will finally help him and his wife to the longed-for farm inheritance.
Maria lives with her grandfather in a secluded fishing hut on Lake Constance where they barely survive on what the fishing grounds provide. The daughters from next door make things worse by scaring away the fish with their motorboat. But Hans, the son of a rich family, falls in love with Maria and tries to help her, although she is unsure if he can be trusted.
The unscrupulous dealer Haslinger has paid off a debt note worth 1000 Mark from the peasant Kreithofer and now wants the man’s farm in return for the debt settlement. Then, suddenly, a rumor pops up that Grandfather Kreithofer is a rich man, who wants to leave his entire estate to his grandchild Lois. Grandpa started the rumor to help his grandson out of the mess, who, as luck would (not) have it, is also in love with Haslinger’s daughter, Ev. But no sooner does Haslinger hear of this rumor, that he wants the old man to move in with him, leave the debt to him and give permission for the kids to marry.