Isabel Gillies had a wonderful life-a handsome, intelligent, loving husband who was a professor; two glorious toddlers; a beautiful house in their Midwestern college town; the time and place to express all her ebullience and affection and optimism. Suddenly, the life Isabel had made crumbled. Her husband, Josiah, announced that he was leaving her and their two young sons. "Happens every day," said a friend. Far from a self-pitying diatribe, Happens...