Features a guest appearance by Michael Kitchen, who would go on to become the star of another long-running British detective series, Foyle's War (2002).
The two arias Nicole Burgess sings are Caro Nome from Rigoletto, by Verdi, and Signore Ascolta from Turandot by Puccini. Both are the songs of tragic women who sacrifice themselves for men.
This is the second of only three times that John Thaw and his wife Sheila Hancock appeared together in TV dramas. The other two were S1, E7, The Way We Were (1985) of Home to Roost (1985) and S3 E2, Blood Money (1997) of Kavanagh QC (1995).
The villa at which Morse interviews Frances Barber's character is the Villa Rocca Pisana, a 16th century villa in Vicenza designed by Vincenzo Scamozzi in the Palladian style for the Pisani family.