1940, the Blitz, London. In the middle of the Second World War, United Kingdom needs help from new allieds, specially from United States. They decided to film a patriotic movie for calling their attention, so they hire Catrin, a young screenwriter for make the movie. But the also hired Buckley, another experienced screenwriter. Both should work with Ambrose Hilliard, and old eccentric star who will starring this film. Directed by Lone Scherfig, director od 'Italian for Beginners', 'Wilbur Wants to Die', 'An Education', 'One Day' and 'The Riot Club', the film is based in the novel 'Their Finest Hour and a Half', written by Lissa Evans, and it's starring by Gemma Arterton, Sam Claflin, Bill Nighy and Jack Huston.