It is 1940. France has fallen. Bombs are dropping on London. And President Roosevelt is promising he wont send our boys to fight in foreign wars. But American radio gal Frankie Bard, the first woman to report from the Blitz in London, wants nothing more than to bring the war home. Frankies radio dispatches crackle across the Atlantic Ocean, imploring listeners to pay attention – as the Nazis bomb London nightly, and Jewish refugees stream across Europe. Frankie is convinced that if she can just get the right story, it will wake Americans to action and they will join the fight. Meanwhile, in Franklin, Massachusetts, a small town on Cape Cod, Iris James hears Frankies broadcasts and knows that it is only a matter of time before the war arrives on Franklins shores. In charge of the towns mail, Iris believes that her job is to deliver and keep peoples secrets, passing along the news that letters carry. And one secret she keeps are her feelings for Harry Vale, the town mechanic, who inspects the ocean daily, searching in vain for German U-boats he is certain will come. Two single people in midlife, Iris and Harry long ago gave up hope of ever being in love, yet they find themselves unexpectedly drawn toward each other. Listening to Frankie as well are Will and Emma Fitch, the towns doctor and his new wife, both trying to escape fragile childhoods and forge a brighter future. When Will follows Frankies siren call into the war, Emmas worst fears are realized. Promising to return in six months, Will goes to London to offer his help, and the lives of the three women entwine. Alternating between an America still cocooned in its inability to grasp the danger at hand and aEurope being torn apart by war, The Postmistress gives us two women who find themselves unable to deliver the news, and a third woman desperately waiting for news yet afraid to hear it.