THE LOS ANGELES TIMES – London, 1940, amid the panic of the Blitz: Copywriter Catrin Cole (Gemma Arterton) has landed a job scripting women’s dialogue for war films at a British ministry desperate to boost the national spirit, when she’s given a plum piece of advice from a co-worker (Sam Claflin) on writing for female moviegoers.

“Girls don’t want to be the hero,” he declares with chauvinist condescension in “Their Finest,” the new World War II-set period drama from director Lone Scherfig (“An Education”). “They want to be had by the hero.”

It’s a galling line played pitch perfect to rankle audiences through the lens of a more progressive today — even if many inside Hollywood argue that, too often, Hollywood still agrees.

“That’s how it was back then,” Arterton says on a recent afternoon in Los Angeles, shaking her head in faux anger. “And that’s something I like about this film. Catrin comes in [to her new job] and they say, ‘Obviously, we can’t pay you as much as the men’ — and because it’s that period, she just kind of accepts the sexism.”

At least, to start. Based on author Lissa Evans’ 2009 novel “Their Finest Hour and a Half,” “Their Finest” tracks Catrin’s blossoming empowerment as she’s propelled headfirst into the production of a fact-based Technicolor war epic set against the rescue of Dunkirk.

Working her way up from writing the “slop” — the derogatory term male writers used for female dialogue — she finds her voice by writing the film’s female characters into heroes in their own right, and then by protecting them from having their agency erased off the screen by her male colleagues.

Meanwhile, amid the organized chaos of moviemaking with a colorful crew of egotistical actors, anxious ministry producers, a pretentious director and the sexist co-writers who begrudgingly come to respect her talents, Catrin brings her quiet battle home, where her narcissistic artist-husband (Jack Huston) has his own ideas about his wife having a career of her own.