A group of young women from Smith College risk their lives in France at the height of World War I in this sweeping novel based on a true story. Betsy Rutherford is looking for volunteers to help French civilians decimated by the German war machine and Kate Moran reluctantly agrees at the behest of her best friend. Four months later, Kate and seventeen others set sail for France, but the region is in complete disarray. With the Germans threatening to break through the lines, can the Smith Unit pull together and truly be a band of sisters?