The year is 1940 and the British have their backs to the wall. Everyone is preparing for the battle that, as Winston Churchill said, would see the "whole fury and might of the enemy turned upon us." Everyone including the young Miss Emily Seeton, London art teacher, who finds her strangely prophetic sketches do not go unnoticed by the secret services. At first suspected of being a fifth columnist, she soon finds herself recruited by the dashing Major Gerry Haynes and sent to carry out a very special observance task at a rural Spitfire factory. Faced with bombs, sabotage and murder, Miss Seeton must summon all her courage - it is after all her nature to Keep Calm and Carry On!