Mark and Hermia have paintings of four English nobles on horseback over their bed. These are likely meant to represent the four horsemen of the apocalypse.
One of The Pale Horse's most memorable locations is that of Much Deeping, a village in the countryside with strange traditions and a link to Easterbrook's late first wife. These scenes were filmed in Bisley, a small village in Gloucestershire which had a population of just 2,142 people at the time of the 2011 census. The Pale Horse pub that features in the series (and with which it shares a name) were shot in Bisley's The Bear Inn, which doubles as a four-star hotel.
The car that Mark Easterbrook drives is a Lagonda Coupe 1956.
A Miss Marple version was done starring Julia McKenzie. The book on which the adaptations are based, does not feature Miss Marple. It does, however, feature Ariadne Oliver, who appears in several books which feature Hercule Poirot. She even appears in some of the Poirot episodes. Though she does not appear in this adaptation.
There are sculptures of three faces in Mark and Hermia's flat, representing the three witches watching over them.