To look at one was to see the other. For her family, even the girls' own father, it was a constant guessing game. For strangers, the surprise was overwhelming. And for the twins Olivia and Victoria Henderson, two remarkable young women coming of age at the turn of the century, their bond was mysterious, marvelous, and often playful -- a secret realm only they inhabited.Olivia and Victoria were the beloved daughters of a man who never fully recovered from his wife's death bearing them in 1893. Shy, serious Olivia, born eleven minutes before her sister, had taken over the role of mother in their lush New York estate, managing not only a household but her rebellious twin's flights of fancy.Free-spirited Victoria wanted to change the world. She embraced the women's suffrage movement and dreamed of sailing to war-torn Europe. Then, in the girls' twenty-first year, as the First World War escalated overseas, a fateful choice changed their lives forever.It began when Victoria's life was about to become a public scandal. It led to a painful decision, and brought handsome lawyer Charles Dawson into the Hendersons' life and family. Hand-picked by the twins' father to save his daughter's reputation, Charles was still mourning his wife's death aboard the Titanic, struggling to raise his nine-year-old son alone, determined never to lose his heart again. Charles wanted to believe that for the sake of his son he could make an unwanted marriage work. But in an act of deception that only Olivia and Victoria could managa, the twins took an irrevocable step, which changed both their lives forever; and took one of the twins to the battlefield of France, the other into a marriage she longed for but could not have.