Desc: Kulový blesk: Directed by Zdenek Podskalský, Ladislav Smoljak. With Rudolf Hrusínský, Karel Kalas, Josef Abrhám, Daniela Kolárová. In the flat of the retired opera singer Bílek there is a meeting of people wishing to exchange their flats. The "duodeca-exchange" is organized by a lawyer Radosta (Rudolf Hrusínský), who labeled the action "the lightning ball". The preparations are accompanied by many unexpected problems.