During the Battle of France in June 1940, RAF pilots evacuate a small airfield in advance of the German "Blitzkrieg". The pilots, along with British and French military, leave just as German aircraft arrive and execute a heavy strafing attack. RAF Air Chief Marshal Hugh 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.