At 42, New Hampshire ski salesman Frank Cadwallader has settled into an increasingly lifeless marriage. A lifelong Quaker, he joins a peace mission to the Soviet Union, but the first cracks in his familiar world appear before he leaves—Russian lessons lead to an obsession with his alluring teacher, Olga, whose own titillating secrets prove nearly as surprising as Frank’s attraction to her. More importantly, she awakens an intellectual curiosity that expands once Frank reaches Finland and Russia: “He was uncomfortable,” the author writes of Frank’s first forays into nude saunas, “but he liked being uncomfortable like this.” As the Quaker delegation discusses nuclear disarmament with its Soviet counterparts, Frank is enthralled by the history, politics, and customs of a world far from his own. He’s equally captivated by Immi, a married Finnish nurse with whom he continues to correspond after returning home. Their letters sustain a profound relationship as Frank changes careers and his wife, Mary, immerses herself in caring for AIDS patients. Von Reyn follows these relationships across decades, weaving historical events into the chronicle of the characters’ changing lives. As he and Mary enter into what Frank dubs “marital intimacy reimagined,” his love for Immi endures, but old age comes for all the characters as their hope for reinvention collides with the inevitability of loss. The author conveys his characters’ thoughts with precision and beauty, deftly capturing Frank’s awe at Finnish summers and his obsession with the woman he can’t have. Some clumsy dialogue works too hard to explain epidemics, Quaker beliefs, or geopolitics, but the swiftly evolving story minimizes such shortcomings with surprising developments and sharp integrations of historical events. (The Challenger explosion becomes an obstacle to Frank’s long-awaited contact with Immi, for example.) Ultimately, this tale of separated lovers transforms a classic romantic setup into something relatable and deeply moving, with smart ruminations on desire, curiosity, and growing older.