New York, 1937: When estranged sisters Clara and Madeleine Sommers learn their grandmother is dying, they agree to fulfill her last wish: to travel across Europe together. They are to deliver three letters, in which Violet will say goodbye to those she hasn't seen since traveling to Europe forty years earlier; a journey inspired by famed reporter, Nellie Bly. Clara, ever-dutiful, sees the trip as an inconvenient detour before her wedding to millionaire Charles Hancock, but it's also a chance to embrace her love of art. Budding journalist Madeleine relishes the opportunity to develop her ambitions to report on the growing threat of Hitler's Nazi party and Mussolini's control in Italy. Clara and Madeleine wonder if they can fulfil Violet's wish, until a shocking truth about their family brings them closer together. But as they reach Vienna to deliver the final letter, old grudges threaten their reconciliation again.