"The Borough Treasurer" is set in Highmarket in the north of England and begins in the offices of the successful building firm of Mallalieu & Cotherstone. The two partners, who are community members and serve on the local council, become embroiled in a scandal when a retired detective, Mr. Kitely, recognizes them from their past as fraudsters who had gone to prison. Kitely threatens to expose their history but is found murdered the same night. Both partners suspect each other of the crime as the police investigation begins, but another man is also arrested. The novel explores the mystery of who committed the murder and how it relates to the partners' past.