A Fatal Grace by Louise Penney.
Welcome to winter in Three Pines, a picturesque village in Quebec, where the villagers are preparing for a traditional country Christmas, and someone is preparing for murder. No one liked CC de Poitiers. Not her quiet husband, not her spineless lover, not her pathetic daughter—and certainly none of the residents of Three Pines. CC de Poitiers managed to alienate everyone, right up until the moment of her death. When Chief Inspector Armand Gamache, of the Sûreté du Québec, is called to investigate, he quickly realizes he’s dealing with someone quite extraordinary. CC de Poitiers was electrocuted in the middle of a frozen lake, in front of the entire village, as she watched the annual curling tournament. And yet no one saw anything. Who could have been insane enough to try such a macabre method of murder—or brilliant enough to succeed?