Edward Fox (Dr. Yardley) is Laurence Fox's uncle. This is now the fourth Fox to guest appear in the "(Inspector) Lewis" series. Laurence's father, James Fox, played Professor Deering in an earlier episode, "Allegory of Love (2009)." Lauence's brother, Jack Fox, guest starred in "Your Sudden Death Question (2010)" and Laurence's cousin, Freddie Fox, (Edward's son) was in "Generation of Vipers (2012)".
In the 2 hour tv movie length edit version of the 7th series, this is episode 3, originally intended as the last episode of the series, and the very final episode of "Lewis". Understandably, Kevin Whately had started to become tired of playing Robert Lewis, in 60 tv movies, including his entire run of the earlier "(Inspector) Morse" series. He was later persuaded to return for the final 6 episodes of Lewis, unofficially known as "(Inspector) Hathaway".
When Lewis is tidying up and flipping through records, he finds Wagner's "Lohengrin." When he turns the record over, a message is written on the sleeve: "At least give it a try... M." Viewers can assume that the record was a gift from Morse, who favoured Wagner.
In addition to acting in this episode Stephen Churchett (Richard Seager) wrote the story or screenplay for 7 episodes of Lewis, including this one.
Parts 1 and 2 were combined into a 97-minute feature length film for video release and for some syndication presentations.