In April 1917 a charismatic Smith alumna, Betsy Hayes Harwood, delivered a speech at the Smith College Club, urging her fellow alumnae to take immediate and personal action to alleviate the humanitarian crisis in war-torn France. Katie Moran never intended to take up the call—she’s not like the other Smithies. But when her former best friend Emmeline Perkins reaches out and begs Katie to join them, Katie finds herself reluctantly agreeing, in part to pay off an old, unspoken debt. Four months later Katie arrives in France with seventeen other alumnae who comprise the Smith College Relief Unit—including two female doctors, a rare novelty at the time. But despite constant shelling and furious interference from the male officers of the American, French and British armies, the Smithies manage to bring real aid—and hope—to the region, all while navigating old rivalries, new betrayals, and inconvenient romantic entanglements.