Alright the third trivia concerning devil in the dark was that it was tied with where no man has gone before and what are little girls made of as the first season episodes with the fewest number of recurring characters speaking. In where no man has gone before Kirk Spock Scott and Sulu all speak. In what are little girls made of Kirk Spock Uhura and Chapel all speak. And in Devil in the dark Kirk Spock McCoy and Scott all speak. But in none of those three episodes do any other recurring characters speak. I believe 4 is the minimum number that ever happened on the original series as far as regulars with speaking parts. I know that all our yesterdays had Kirk Spock McCoy and Scott speak even though Scott did not make a physical appearance. Was no one interested in making a guess on the number of episodes a Starfleet shuttle appeared on the series? I'm not including TOS remastered where they may have added shuttles for external scenes as I think they did in court-martial.