Ruth Larson saved nearly 700 letters she and her husband Bob exchanged during World War II. Opening the box while his mother lay dying, her son Bruce expected to find commonplace details of his parents' early life together. He instead discovered a story of deception, obsession, and betrayal.

Reading through the letters, he is drawn into his parents' courtship amid the hardships of separation and war. Beyond the tumultuous romance, Larson finds that he barely recognizes his father, whom he knew only as distant and impassive. He uncovers shocking truths about his mother, Ruth, whom family lore had pigeonholed as sweetly pious.

At the time of the letters, Bob is a young Coast Guard clerk fighting off depression with thoughts of his dream girl back home. Back in Minnesota, Ruth passes the days adrift in romantic fantasies and liaisons with local admirers. Bob's suspicions about Ruth and his obsession with her from afar threaten the young man's fragile hold on his sanity, but he will not give her up. Decades later, their son comes to feel a tenderness for both his parents and to understand how their losses, fears, and reluctance can transform and refashion family bonds.