Margaret and Peter come to Elizabeth with a request. With a royal scandal about to break in the newspapers, the Queen Mother intervenes.
- Philip, Duke of Edinburgh was an active participant in a long-standing men's gourmet society he calls "The Lunch Club" (or more officially, The Thursday Club). A typical meeting might include 10-15 members, including Philip, Lord Louis Mountbatten, actors David Niven and Peter Ustinov or photographer Cecil Beaton. The club meeting featured was held in a second-floor event room at Rules, the oldest restaurant in London.
- Gelignite is a type of explosive. The title serves as a metaphor for the impact of the news of Princess Margaret's involvement with Group Captain Peter Townsend.
- Lambeg drummers are drum corps from among the Unionist (Protestants) of Northern Ireland, and are strongly associated both the historical domination of the Catholics of Ireland, and in particular, the "Marching Season", when Protestant organizations engaged in marches through the Catholic neighborhoods, celebrating the victory of William of Orange at the Battle of the Boyne.