In this story, Steed reminisces about his days in the army just after World War. However, in an earlier segment, The Hour That Never Was (1965), he specifically says he was in the Royal Air Force. In reality, Patrick Macnee, who plays Steed, was in the Navy.
The villain of the piece is taking revenge on the men who had him imprisoned many years before. Since escaping from jail, he has become immensely wealthy and now uses the pseudonym of "Monty Bristow" whilst exacting his vengeance. One can hardly avoid being reminded of "The Count Of Monte Cristo" by the name, or the similar plot; however, in that story, Monte Cristo was imprisoned unjustly, whilst here "Bristow" was guilty.
For Steed a new partner and a change of car, moving from his trusty green 1927 Bentley licence plate YT 3942, for a 1923 yellow and silver Rolls Royce (KK 4976). Feb 2021, both vehicles registered as active on UK DVLA website.
The scene where the Games Master quickly completes the jigsaw is actually footage of someone taking apart the jigsaw with the film reversed and speeded up.