When Cornelia leaves her cruel uncle's home to join Napoleon's army as a traveling naturalist, her ability to heal any wound and bring soldiers back from the brink of death brings her praise from higher-up - and puts her in the path of those who would exploit her powers for themselves. Meanwhile, Lijsbeth lives in indentured servitude, her only respite her time spent flower arranging. When she meets a young English soldier and falls in love, Lisjbeth must decide whether to flee the clashing of two great armies at Waterloo, or risk everything by staying. And when the sisters finally meet on opposite sides of the battlefield, they must work together to solve the mystery of their mother's death and their father's disappearance, all while surviving the war raging around them.