A first appearance for Imogen Quy (rhymes with ``why''), an English school nurse with a flair for detection. She lives and works in Cambridge, at St. Agatha's College, where routine academic life is roiled by the death of student Philip Skellow--found dead on the floor of the locked Wyndham Case--a highly specialized library overseen by foppish Crispin Mountressing, who's an overpaid object of envy and contempt to Imogen's friend Roger Rumbold, director of the college's ``real'' library. Philip shared living quarters with campus hotshot Jack Taverham, now suddenly vanished, whose upper-class background and adoring friends contrasted sharply with Philip's bumpkin ways, making him the butt of cruel jokes--one of which may have led to his death. No joke was involved in the murder of third-year med student Felicity Marshall, but the message she left before she died helps lead Imogen and her policeman friend Mike Parsons to an obsessed killer and to the happy resolution of some troubling lesser problems on campus. A leisurely, literate style, an intriguing clutch of academic eccentrics, a clever puzzle, and a sharply intelligent sleuth whose gentleness sets her apart from the hard-edged aggressions of her fictional contemporaries--all in a refreshing debut in the Sayers tradition.