Unlike Barbara Bain, Phil Morris does not reprise his Mission: Impossible character in this spy get together even though the character he plays here was the son of another spy just like his Mission: Impossible character.
The character Drake that Robert Vaughan plays could be a nod to John Drake, the character that Patrick McGoohan played in the spy series Danger Man (or Secret Agent to American audiences) before he went on to become the Prisoner.
This episode uses several actors who portrayed secret agents on other series. Barbara Bain reprises her Cinnamon Carter character from Mission: Impossible, Robert Culp acted in I Spy, The Name of the Game and The Greatest American Hero, Patrick Macnee appeared in The Avengers , Phil Morris in the 1988 Mission Impossible, and Robert Vaughn starred in several series including The Man from U.N.C.L.E. and The Protectors.