It is set in the British colony of Kenya in the 1930s, and tells the true story of murder of Josslyn Victor Hay, the 22nd Earl of Erroll, as seen through the eyes of 15 year-old Juanita Carberry, the daughter of John Carberry, a friend of Broughton's.
Lord Erroll's murder was also dramatised in the feature film White Mischief, which was released several months after the first transmission of The Happy Valley.