Lauren Groff’s new novel Fates and Furies starts out innocently enough. A young couple, Lotto and Mathilde, has just gotten married and decide to celebrate—in a carnal sense—on a chilly Maine beach. The book unfolds in two parts: Fates is the story of Lotto, a handsome and successful playwright. Then the second half, Furies,takes a Gone Girl-style narrative turn and is told from the more raw point of view of Mathilde.