Young prisoner Jan, nicknamed Roughboy (Petr Cepek), tries to commit suicide. He was imprisoned for a fight in which he injured a functionary of the National Committee and for stealing material but actually by the blame for this crime was pinned on him by the road-builders in whose group he worked. The prison doctor knows that Jan is an emotionally deprived person who never knew his parents and spent all his childhood - except one year with foster-parents - in orphanages, homes for youth and reform schools. He arranges a five-day holiday for Jan, who wants to find his mother's grave.

A comedy about exchange of 12 apartments , which, its organizer, lawyer Radosta, rightly called Action Ball Lightning. To prepare, organize and execute the exchange of twelve apartments is a work worthy champions. Radosta, who was excellently played by Rudolf Hrušínský, solved all sudden difficulties and complications on the fly and with grace. To be sure that the on the D-day everything goes well he prepares a little rehearsal, which reveals many minor issues caused for example by wedding ordered to inappropriate term or hesitation of some participants. Last but not least a night exercise announced by drunk psychologist Knotků, creates a lot of confusion that nearly sabotaged the whole operation.

The lives of 7 friends in a small Czech town from 1945 to some time after 1958.