The film "Kulový blesk" is about the biggest maneuver in the history of moving: an apartment ring exchange with 12 parties involved. Everyone has to move on the same day, everything has to work, otherwise the chain will fall apart. dr Radosta is an experienced organizer of such actions, but there has never been a 12-ring exchange. This is world-class moving! And it's like watching for fleas. There is always someone wanting to change something, wanting to get an advantage, or has changed their mind and prefers not to move. Some get divorced, others have to marry quickly beforehand. dr Radosta and Knotek, his semi-voluntary assistant, have their hands full. And when it starts, of course, everything gets much worse.