I read a book a few years ago by some insiders from the Star Trek show. It was fascinating to hear what they had to say about Roddenberry, Shatner and the whole experience. One of the things about the book that stood out in my mind was their opinion about the 3rd season. Although the show had almost been canceled early on and Gene Roddenberry instigated a letter-writing campaign to save the show, by the final season, they felt that Roddenberry had given up on the show and actually spend much of this season on other projects. This, they said, accounted for the often sub-par scripts used in them. And, looking back at it, season three had plenty of duds and plenty more only watchable episodes that were pretty easy to forget. This episode is one of the forgettable ones, as not a whole lot of energy is in it. There's a weird space killer that makes people talk in a goofy froggy voice and Scotty seems strangely attracted to a froggy-voiced lady that somehow has survived one of these attacks. That's it--the rest of it just isn't worth discussing, as it just seemed to go nowhere.
Review of The Lights of Zetar
