Based on Lissa Evans's novel Their Finest Hour and a Half, the new movie Their Finest tells the story of a Welsh woman, Catrin Cole (Gemma Arterton), who becomes a screenwriter for English WWII propaganda movies. At first, she gets the job because she can write "slop" (a.k.a. "girl talk"), but it turns out she's every bit as talented as her male cohorts, and they know it. The movie-within-a-movie, based very loosely on the true story of two sisters attempting to rescue soldiers from the beaches at Dunkirk, goes through many changes. Various departments and studio heads and actors, etc., all have ideas about how the movie should go and what it should say, and Their Finest tracks these changes with incredible believability.