A new, non-series mystery from the author of the delightful tales of Mary Russell, a Jewish teenager in Victorian England who befriends her neighbor, the retired Mr. Sherlock Holmes (The Beekeper's Apprentice). Folly is darker, and to my mind less completely successful. King (like Arthur Conan Doyle) thrives on her minor characters, and Folly necessarily isolates its aging hero, Rae Newborne, on an uninhabited island named (for her ancestor) Newborne's Folly. Nonetheless, a very worthwhile book and (I hear) a strong contender for major awards.