Klaus Blume is a magistrate (local judge) in a provincial Austrian town. He's amiable and liberal, and ocasionally clashes with the narrow minded Official Prosecutor Peter Seiler. Blume's sister has died, leaving three children orphaned, living alone, although Blume is keeping an eye on them. The sister came into an inheritance ... 3 million Swiss Francs ... just before she died, and a Swiss lawyer is coming to make the arrangements for the payment, which has not yet been made. The children beg Blume to dress in his sister's clothes and impersonate her. Incredibly ... he is a judge ... he allows himself to be persuaded to do so. Menawhile the Children's Welfare department is aware that the children are living alone. So what is more natural than for Blume to meet the Welfare lady in the guise of his sister, to reassure her. Problem solved. Blume's next case in court involves a bank robber who dressed as a woman to carry out the deed; Peter Seiler as prosecutor is waxing lyrical about the moral dimension of impersonating a woman, when he notices a bra hanging out of Blume's briefcase. Oops. The Swiss lawyer arrives, and she is an attractive woman. Blume meets her in his office without relising exactly who she is, and after some tension, they agree to have dinner together. Blume has never married and is feeling the need for female company, and things go well. Now Blume has to meet the Swiss lawyer as his own sister so as to get approval for the money. Amazingly the interview is very brief, and onbly involves showing "her" passport as proof of identity. It's not a very good likeness, but the lawyer is satisfied. Blume (as his sister) also gets manipulated into attending the local Summer Festival with her ... tricky as he has to be there as himself, ex officio. (Are you keeping up with all this?) So he is at the dinner-dance for the festival in both modes, as himself and his sister, involving quick changes in the lavatories. Seiler, the mean prosecutor, is chasing the "sister", perhaps because of the 3 million francs. Where will it all end?