“Friday’s Child” ***
The landing party must negotiate mining rights with a primitive people while the Enterprise is challenged by a Klingon warship.
All things considered this really is an average run-of-the mill episode, and yet it has quite a few fun moments in it. McCoy is a riot in his interactions with Eleen. And I really like Scotty's turn in command along with Sulu and Chekov and Uhura supporting. In this Scotty isn't yet the excitable engineer but has his own distinct professionalism and composure.
The primitive peoples in this are rather cardboard, though. And Tigre Andrews makes for a truly lousy Klingon.

He has no distinct speech manner and they couldn't even bother to give him some make-up. Additionally while some of the music was neat quite a bit of it was just a little too obtrusive and some of it didn't fit the story's setting and atmosphere.