Enemy Brothers: A Story of World War II by Constance Savery

British airman Dym Ingleford is convinced that the young German prisoner, Max Eckermann, is his brother Anthony who was kidnapped years before. Raised in the Nazi ideology, Tony has by chance tumbled into British hands. Dym has brought him back, at least temporarily, to the family he neither remembers nor will acknowledge as his own. As Tony keeps attempting to escape, his stubborn anger is whittled away by the patient kindness he finds at the White Priory. Then, just as he is resigning himself to stay with this English family, a new chance suddenly opens for him to return home—to Germany!