1940, London, the Blitz; with the country’s morale at stake, Catrin (Gemma Arterton), an untried screenwriter, and a makeshift cast and crew, work under fire to make a film to lift the nation’s flagging spirits; and inspire America to join the war. Partnered with fellow writer, Buckley (Sam Claflin), the pair, along with fading matinee idol Ambrose Hilliard (Bill Nighy), reluctantly joins forces on a movie to warm the hearts of the nation and capture the imagination of the US public.