DCI Barnaby quotes the Hughes Mearns poem "Antigonish" to Sergeant Troy.
Hannah Harrington mentions witch burning, however, witches were hanged in England, not burnt.
Emily Joyce plays Bernadette Sullivan in this episode. She returns in episode 16.1, The Christmas Haunting (2013), in the role of Valerie Fergus-Johnson.
Adam Kotz plays James Harrington in this episode. He returns in episode 17.1, The Dagger Club (2015), in the role of Nick Summersbee.