Easily one of the best of the third season. It gets some criticism for supposedly having Spock look stupid at the end of the episode, but dramatically could it really have been written any other way? It would also have been a better episode if they had let Garth in Kirk's guise get aboard the ship. What ever happened to the drug that seemed to work at the end of this episode? Dr. Sevrin ("The Way to Eden") and Janice Lester ("Turnabout Intruder") were both pronounced insane in episodes following this one, and no mention is made of using the drug to cure their insanity.