Willis brings so very much to this sf/mystery/comedy of manners: time-traveling historians, country houses in Victorian England, 1930s murder mysteries, _Three Men in A Boat (To Say Nothing of the Dog)_ by Jerome K. Jerome, Coventry Cathedral, ULTRA, the battle of Waterloo, and of course, the bishop's bird stump--that it makes this book kind of hard to describe. but nonetheless very enjoyable. It's a real genre-bender with a lot of humor and very highly recommended.