From the Pultizer Prize-winning author of 'The Hours', comes the story of a marriage thrown off course by a moment of mistaken identity. Peter Harris is forty-four, prosperous, the owner of a big New York apartment and a player in the contemporary art scene. He has been married to Rebecca for close to twenty years. Their marriage is sound, in the way marriages are. Peter might even describe himself as happy. But then Rebecca's much younger brother Mizzy shows up for a visit. Beautiful, twenty-three years old, with a history of drug problems, Mizzy is looking for direction. And in his presence, Peter finds himself questioning his marriage, his desires, his career - the entire world he has so carefully constructed for himself. Making us think deeply about the uses of beauty and the place of love in our lives, By Nightfall is heartbreaking look at the way we live now.