Not really looking forward to this one. I hope I can manage to watch at least semi-objectively.
"And the Children Shall Lead" by Edward J. Lakso
Responding to a distress signal, Kirk, Spock, and McCoy beam down to a research colony on Triacus. They find several dead bodies. One man gets up briefly and Kirk recognizes him as Professor Starnes, but Starnes doesn't seem to recognize Kirk and he collapses, dead. They determine that the dead committed mass suicide. Then the children of the colony come out. They are laughing and playing like nothing's happened. This continues as Kirk, Spock, and McCoy bury the bodies and then beam the children onto the ship. Spock speculates an outside force may be involved. Kirk feels a strange anxiety when entering the cave the children were playing in.
Later, the children are sent to bed, but instead chant and summon their "friendly angel." The "angel" lays out the plan - the children are to manipulate the crew and ship to go to a populous planet, where it will command millions and they will be its generals.
Spock managed to get logs from Starnes' tricorder and plays them for Kirk. Just as the last one is playing, the oldest child, Tommy, comes onto the bridge and stops it from working. Gradually, using illusions and the crew's fears, the kids take over the ship and send it where they want it to go. Spock breaks himself free and helps Kirk do the same.
Kirk eventually plays back the chant to summon what he suddenly calls the Gorgan and confronts it. Spock plays back footage from Starnes' tricorder showing the children laughing and playing with their parents, then the footage of them all dead. The children start crying, releasing the Gorgan's hold and showing it as the ugly, nasty thing it really is. It disappears and everyone is freed from the illusions and control.
So, the Gorgan is "the evil embodiment of an ancient group of space-warring marauders released by Starnes's archaeological survey." Weird, but Trek.
The episode is surprisingly watchable, up until they summon the Gorgan on the bridge and Sulu sees swords in space and Uhura sees herself old and sick. George and Nichelle do fairly well in those scenes. Belli is terrible throughout and his monologues are too long, destroying the mystery of the story on his first appearance. Shatner goes way overboard when his fears take control of him, but otherwise is fine. The kids were all pretty decent, especially when they finally react to their parents' deaths.
I won't go as far as others and say it's the worst TOS episode, but it definitely falls apart after the first half. I found the episode oddly resonant given current events in the world.