The 'Blade on the Feather' title was derived from a line in the lyrics of the ''Eton Boating Song" which itself is also heard being sung in this tele-movie.
Based on the same real life events as Another Country (1984), Cambridge Spies (2003), History in Faces: Cambridge Five (2011), Philby, Burgess and Maclean (1977), A Question of Attribution (1991), An Englishman Abroad (1983), Tinker Tailor Soldier Spy (2011), Tinker Tailor Soldier Spy (1979), Traitor (1971), Blunt (1987), The Jigsaw Man (1983) and influenced the source novels of The Fourth Protocol (1987), The Innocent (1993) and others works such as A Different Loyalty (2004) and Olding (2019), even in minor form like in The Imitation Game (2014).
This tele-movie was first broadcast about eleven months after Anthony Blunt in 1979 was uncovered as the 'fourth man' of the Cambridge Five (a group of university educated students working for the Russians between the 1930s and the 1950s).
The name of the fictional fantasy novel for children that Professor Jason Cavendish (Donald Pleasence) had written was ''Cloud Cape''.
Actors Tom Conti and Donald Pleasence both later appeared in Robert Altman's 'Basements' (TV) (1987) but appeared in separate segments they being ''The Dumb Waiter'' and ''The Room'' respectively.