This one starts off a bit like a bad John Candy vehicle but after a certain point all pretenses are dropped, the silliness level breaks past 10, and you find yourself wondering why they didn't do a Mudd episode in the 3rd season. Well, they kind of did - they just made him more deliciously and dastardly insane as Garth in From Whom The Gods Destroy.
Not a fan of this one, goes off on a ton of tangents and I feel like the woman in the underground society who says "Brain! What is brain?" a lot. No character knows anything when asked a question in this episode! Somehow, Spock gets his brain back and that's all that counts.
Kirk gets all sensitive with a tough, hard-bodied alien woman, breaks down her defenses, then outwits a bunch of colored brain blobs who live in one of those handle hockey arcade games. Meanwhile, Spock keeps telling everyone how stupid they are when he correctly tells them they need to travel a long ways to find the Captain.. Lesser fun episode.