There are references throughout the story to a police inspector named "McNutt", who will be Morse's new superior after he transfers to Kidlington in the New Year. McNutt featured prominently (played by Iain Cuthbertson) in the famous "Inspector Morse" story, "Masonic Mysteries", where Morse referred to him as a mentor who had left the police force to take holy orders. McNutt was murdered in the course of that story, set some twenty years after this one.
The title of the episode, "Zenana", is a word derived from Hindustani and Persian, meaning "the women's apartments" - sometimes denoting a harem. It is an ironic title, seeing that the story concerns a women-only Oxford college determined not to allow male students, a woman's flat used by others as a love-nest and the terrifying secrets of Jenny Tate's rooms.
The opera Morse attends where he confronts Violeta Talenti is entitled "La Sposa del Demonio" - "The Bride of the Devil"
The characters make a reference to a "cousin Kevin." That is also the name of a song from the rock opera Tommy, about a sadistic cousin who tortures the title character.
When, in his letter to Joan Thursday, Morse describes her father as "the best and wisest of men", he is echoing a description of Sherlock Holmes made by Dr. Watson in Sir Arthur Conan Doyle's story "The Final Problem".