Gaudy Night was published in 1935 and is the longest, the most ambitious, and to many readers the best of the Lord Peter Wimsey novels. The setting is the fictional Shrewsbury College, a women’s college at Oxford modeled on Somerville, the college Sayers had attended. Harriet Vane returns to Shrewsbury for a Gaudy reunion dinner and is drawn into investigating a series of anonymous poison-pen letters and increasingly disturbing harassment incidents directed at the college’s women dons.
The book is unusual in the canon because the mystery itself is secondary to the social and intellectual material. Sayers uses the novel to argue at length for the right of women to pursue intellectual work as a vocation, against the period’s pressure to subordinate that work to marriage and family. The argument is conducted not just by speeches but through the structure of the novel itself. Lord Peter appears only in the second half. When he does, it is to support Harriet’s investigation rather than displace it. The eventual romantic resolution between Peter and Harriet is one of the most genuinely earned in detective fiction. Read this one after Strong Poison and Have His Carcase.