Is this the "worse" Star Trek TOS episode? Maybe, at least it gets my vote as being in the bottom 5. I mean, this episode makes absolutely no freaking sense. Seeing something that makes you go mad? Give me a break. This episode also has a different feel to it, the music is heightened, almost forced to enhance a feeling of distress, to the point that it sucks. Give me some Klingons, Gorns, Tholians, Romulans, higher beings like Triskelion's or anything but Medusin's, these are very boring aliens to make an episode around. McCoy gets to utter his famous phrase "He's Dead, Jim". Spock puts on the protective goggles when transporting the ambassador away but Kirk does not. They go through that freaking "barrier" now for the third time that I can remember, boring. At least season three's next episodes would be "Spectre Of The Gun", and "Day of The Dove" and others to follow, making Trek a decent show to watch in syndication where it would pick people like me up as avid fans. Personal observations, Trek loved to use the color purple, its kind of a pinkish purple, like when they are in the corridor outside the compartment, the gangway that is normally grey is now purple. We never had a purple bridge but its interesting to see, I noticed it in several episodes, it was done by a light filter and it works very well but in this episode, in the ships corridor is pretty lame.