A musical comedy about two indistinguishably similar siblings who love music, but each of them is completely different. Pavel Fořt is a professor of classical music at a pedagogical institute, his brother is a jazz musician and plays music in America. When the twin brother suddenly appears in Prague, they switch roles.

The Homolka family celebrates a great occasion: they were finally able to buy a car. They immediately begin to drive for small trips to Hradcany, to the airport, and plan further trips. Their euphoria is spoiled by a letter from their great-grandmother. Their great-grandfather is dying and the family is expected to come along to say goodbye. The annoyed Homolkas therefore set off to the South Bohemian village where the grandparents live.

A hardworking employee at a printing plant takes on all sorts of roles until he nearly collapses under their weight. He learns that those who try to do everything end up doing nothing.