It is early May 1945 and the war is ending. The region adjacent to the river Elbe is full of retreating German soldiers and evacuated townsfolk. The cargo ship "Moldau" with a Czech crew escorted by German soldiers cruises the river. The explosives transported on it are supposed to assist the withdrawal of a German army unit from one of the settlements. Mechanic Rudla (Jaromír Hanzlík), shipman Vrána (Josef Vetrovec) and steersmen Vanis (Eduard Cupák) plan to take flight as soon as the boat arrives on shore, but the Germans keep detaining other men to add to the crew for unloading the dangerous cargo.