The setting for this episode was changed from Colin Dexter's novel of the same name. In the book, the missing girl (called Valerie Taylor rather than Valerie Craven) is a pupil at a seedy council-estate comprehensive school rather than an expensive private girls' school. Her parents live in a small terrace council house rather than an opulent bungalow in its own grounds. These changes were probably made to increase the appeal of the episode to the overseas market. When later adapted for BBC Radio Four, (with John Shrapnel as "Morse") the story reverted to Colin Dexter 's original story.
This features notable early screen roles for Elizabeth Hurley and Julia Sawalha, who both became household names in the next decade.
When Morse and Lewis first talk to the headmaster, Lewis mentions that he and his wife are looking into a school for their daughter Louise to go to. In subsequent episodes of "Inspector Morse", and throughout "Inspector Lewis," the daughter's name is Lynn.
The poem that Grace Craven quotes referring to yellow hair is "For Anne Gregory" by William Butler Yeats.