Set in London in 1940, during the height of the Blitz, Catrin (Gemma Arterton) thinks she’s applying for a secretarial position when she walks into the British Ministry of Information’s film division. But when her supervisor (Richard E. Grant) learns that she has experience as a newspaper copywriter, he hires her for what he surely considers a much worse position: as a writer of “slop” — an old screenwriter’s code for dialogue between women — for the propaganda shorts that run between features at cinemas. With the country's morale at stake, Catrin, Buckley and a colourful crew work furiously to make a film that will warm the hearts of the nation. As bombs are dropping all around them, Catrin discovers there is as much drama, comedy and passion behind the camera as there is onscreen.