Christmas in Prague

In a house in Oxford three people are having breakfast - Carol, her husband Jan, and his father Josef. They are talking about Prague, because Carol wants them all to go there for Christmas. Josef was born  in Prague, but he left his home city when he was a young man. He is an old man now, and he would like to see Prague again before he dies. But he is afraid. He still remembers another Christmas in Prague, many  long years ago - a Christmas that changed his life for ever . . .