London can take it, we are informed by Humphrey Jennings, but Dover is quite all right. The camera may stare at the German-occupied cliffs of Calais twenty miles off. The people in Dover have other things to do, like go roller-skating or take in a movie. Meanwhile, under a barrage of German aircraft conducting the Battle of Britain, the people of Dover man the anti-aircraft batteries and have second jobs. The shopgirl runs the ambulance, and so forth.
That's the message the GPO Crown Unit sent out to movie theaters: deal with the situation, and we'll sort it out later. All those stockpiled posters reading "Keep Calm And Carry On" never had to be used.