To get the mission briefing, Jim asks the store clerk for "Pavane in G", the same piece of music Dan Briggs asked for in Pilot (1966) .
Jim Phelps ( Peter Graves ) describes Cinnamon Carter ( Barbara Bain ) to Captain Olni ( Noah Keen ) as "in her late twenties". Bain was actually 37 at the time and did not look to be still in her twenties.
The testing room is reused, slightly redressed, as the master control room in The Glass Cage (1969).