Spinsters in Jeopardy (Roderick Alleyn Series #17)

Inspector Alleyn has decamped for the South of France for a family vacation. Well, that and a little official poking around. Unfortunately, the object of his poking—the cultish denizens of a sinister and luxurious chateau—are not fond of being poked, and they have a particularly unpleasant way of getting their point across. More a thriller than a whodunit, this is a fresh take for Marsh, while retaining the cleverness and vivid characterizations that her fans demand.