Grace has built her life on order-quiet routines, careful research, and the belief that the past belongs safely behind glass. As a university librarian in the rainy Pacific Northwest, she has always found comfort in systems that behave as expected. But when a forgotten photograph slips from between the pages of a library book, her carefully controlled world begins to fracture. The woman in the image has red hair, a radiant smile-and Grace's face. What follows is not imagination. Vivid memories surface unbidden: candlelit ballrooms in 1930s Berlin, whispered German, flashes of a life that feels more real than her own. Through past-life regression, archived letters, and the graves of people history tried to forget, Grace pieces together a love story buried beneath decades of silence. At its heart is Greta-a brilliant, fearless journalist who refused to look away when the world around her did-and Klaus, a high-ranking German officer whose devotion to Greta crossed every line he was sworn to uphold. He was powerful. He was dangerous. And he loved her in ways that made safety feel like a cage. He kept her close. He kept her in the dark. He told himself it was protection. But as Grace follows the thread deeper across lifetimes and continents, she must confront a devastating question: did Klaus shield the woman he loved from the regime he served-or did his silence make him just as guilty as the men who gave the orders? Rich with atmospheric detail, emotional depth, and moral complexity, Under the Shadow of the Flag weaves historical fiction, romance, and psychological mystery into a story about how we love, what we choose to see, and whether forgiveness can reach across lifetimes. Perfect for readers of The Nightingale by Kristin Hannah, All the Light We Cannot See by Anthony Doerr, and The Alice Network by Kate Quinn.