It is 1940. While war rages in Europe, President Roosevelt promises he won't send American boys to fight. In the small Cape Cod town of Franklin, postmistress Iris James firmly believes that her job is to deliver and keep people's secrets. Meanwhile, seemingly fearless American radio gal Frankie Bard is reporting from the Blitz in London, imploring listeners to pay attention to what is going on. The Postmistress is a tale of lost innocence.