Holy Disorders: Gervase Fen #2

Eccentric Oxford professor Gervase Fen remains as maddeningly childish as ever, still deliciously fond of his own wit and erudition. He's equally fond of amateur sleuthing, so the murder of the cathedral organist is a cause for glee. Could the fellow have fallen afoul of a nest of German spies or of the local coven of witches, ominously rumored to have been practicing since the 17th century? Tracking down the answer pleases Fen immensely?only the reader will have a better time.