The portrait of Sir Hugo is actually a copy of Henri Lehmann's 1840 portrait of musician Franz Liszt, one of whose best known compositions is the Hungarian Rhapsody 2 for piano (a favorite of Bugs Bunny and other cartoon characters)
The horror movie Barnaby is watching is the same mummy movie from "death and the divas" in season 15. He also makes reference to another film that featured in Death and the Divas "Thirst for blood" when telling his wife that he and Betty will be watching a classic film while she is out.
Jack Shepherd is best known for playing another crime fighter Wycliffe.
"The Green Man," the name of the pub that Hannah owned and ran, was also the title of Episode 1 of Series 7.
Deborah Findlay plays Lorna Soane in this episode. She previously played the role of Hilary Richards in episode 3.2, Blue Herrings (2000).