Brave New Episode (only better).
Oft-forgotten (by me, at least), and undeservedly so.
The Enterprise explores a planet where everyone seems placid and calm at all times except during “Festival”, when apparently all the sex, violence, and chaos happens at once. All the people are controlled by some being called “Landru” that Kirk and company try to find out about/fight against.
Highlights:
Sulu’s intro
plot/theme/general ideas
guest actors
Lowlights:
a relatively weak ending (sort of a ‘Changeling’ warmup)
Spockism: “This is a soulless society, Captain. It has no spirit, no spark. All is indeed peace and tranquility: the peace of the factory, the tranquility of the machine.”