Gaudy Night is, in my opinion, the very best of Sayers's fine mystery novels starring Lord Peter Wimsey, younger (and smarter) son of a duke and jack of all trades. For two previous volumes, Strong Poison and Have His Carcase, Peter has pursued Harriet Vane, a mystery novelist whom he saved from being unjustly tried for the murder of her lover, Philip Boyce. Now Harriet takes center stage as she attempts to investigate a mysterious phenomenon which has taken over her old college at Oxford--a combination poison-pen writer and midnight poltergeist that sends abusive anonymous letters and wreaks havoc on buildings and possessions. Uncovering the culprit, however, leads to devastating revelations for her and Peter. Sayers uses the mystery genre here to explore questions of the relationship between career and relationship in men's lives and women's, the nature of love and marriage, and the value of doing one's proper work. Her language is at its richest here, and its portrait of Oxford life c. 1930 is as irresistible as any science-fictional worldbuilding.