The sad hero of the story, Petr, an ordinary lawyer in a construction company, is crowded into a small apartment in Žižkov with his wife and grandparents, desperately struggling with the lack of money. One day he offers an old man a seat on a crowded trolley bus and is generously rewarded for his good deed, for the unknown old man is a fabulous grandfather. He gives Peter a magic bell and the opportunity to make three wishes, but the first two slip through his fingers. For the third, the astonished man must take time to think...