The film deals with the a clandestine Olympiade held in a German POW camp during WW II, housing many Poles, but also French and Brits. A spit and a Polish German lieutenant is added to the staff of a prison camp. He sees a Pole, the acknowledged leader of the Polish prisoners, against whom he had competed during the Berlin Olympics in 1936. He asks the Pole to train with him but is refused; the Pole points out out that he is a prisoner and nothing more. But that plants the seed and the Pole proposes and Olympics 40 to be held among the prisoners. They ingeniously make a flag and medals, set up a number of races; a croaching hop race is unwittingly organized by a German prison guard who uses it as a torture. The German lieutenant knows that something is going on but cannot find out. Finally the Germans realize the idea and the Polish chief is sent to concentration camp but the others disobey the orders.