It is 1940, and bombs fall nightly on London.

In the thick of the chaos is young American radio reporter Frankie Bard. She huddles close to terrified strangers in underground shelters, and later broadcasts stories about survivors in rubble-strewn streets. But for her listeners, the war is far from home.

Listening to Frankie are Iris James, a Cape Cod postmistress, and Emma Fitch, a doctors wife. Iris hears the winds stirring and knows that soon the letters she delivers will bear messages of hope or tragedy. Emma is desperate for news of London, where her husband is working - she counts the days until his return.

But one night in London the fates of all three women entwine when Frankie finds a letter - a letter she vows to deliver...