What would you do if you questioned your religious faith, but revealing that would cause you to lose your family and the only way of life you had ever known? This book tells the fascinating, often heart-wrenching stories of married ultra-Orthodox Jewish men and women in twenty-first-century New York who lead “double lives” in order to protect those they love. While they no longer believe that God gave the Torah to Jews at Mount Sinai, these hidden heretics continue to live in their families and religious communities, even as they surreptitiously break Jewish commandments and explore forbidden secular worlds in person and online. Drawing on five years of fieldwork with those living double lives and the rabbis, life coaches, and religious therapists who minister to, advise, and sometimes excommunicate them, the book investigates religious doubt and social change in the digital age. The Internet, which some ultra-Orthodox rabbis call more threatening than the Holocaust, offers new possibilities for the age-old problem of religious uncertainty. The book shows how digital media has become a lightning rod for contemporary struggles over authority and truth. It reveals the stresses and strains that hidden heretics experience, including the difficulties their choices pose for their wives, husbands, children, and, sometimes, lovers. In following those living double lives, who range from the religiously observant but open-minded on one end to atheists on the other, the book delves into universal quandaries of faith and skepticism, the ways digital media can change us, and family frictions that arise when a person radically transforms who they are and what they believe. In stories of conflicts between faith and self-fulfillment, the book explores the moral compromises and divided loyalties of individuals facing life-altering crossroads.