During the Battle of France in June 1940, Royal Air Force pilots evacuate a small airfield in advance of the Nazi Germany ''Blitzkrieg''. The pilots, along with Great Britain and france military, leave just as German aircraft arrive and execute a heavy strafing attack. RAF Air Chief Marshal Hugh Dowding, 1st Baron Dowding (Laurence Olivier), realising that an imminent invasion of Great Britain will require every available aircraft and airman to counter it, stops additional aircraft being deployed to France so that they are available to defend Britain. In the next dramatic scene, French civilians watch in grim despair as a convoy of German troops marches into France and takes control.