This "powerful, uplifting, and deeply personal novel" (Kristin Hannah, #1 NYT bestselling author of The Four Winds), at once "a heart-wrenching wartime drama" (Christina Baker Kline, #1 NYT bestselling author of Orphan Train) and "a moving and graceful tribute to heroic women" (Publishers Weekly, starred review), asks the question: What if a friendship forged on the front lines of war defines a life...