Kiranide Counterattack
In the episode, the inhabitants of the planet Platonius are found to have powerful psychokinetic abilities. The Enterprise landing party beams down in answer to a distress signal and discovers that the Platonian leader Parmen, played by Liam Sullivan, is suffering from a massive infection that Dr. McCoy successfully treats. During his illness-induced delirium, Parmen radiates such powerful and destructive psychokinetic energy that it threatens to damage or possibly destroy the Enterprise. After he recovers, Parmen feigns gratitude and peaceful benevolence but soon reveals his true despotic nature and forces the landing party, with his overwhelming psychokinetic power, into degrading acts that they are helpless to resist. Because Parmen realizes that he needs Dr. McCoy for future ailments, he refuses to let them leave. McCoy discovers a way to replicate the Platonian power in Kirk and Spock by injecting them with a native mineral known as Kiranide.
Once his own psychokinetic power manifests, Kirk battles Parmen, wins the landing party's freedom, and they depart.
What always interested me about this episode is the idea that Kirk and Spock are able to recreate the incredible mental superpower that the Platonians used to torture and intimidate the landing party and to subjugate Alexander, played by the brilliant Michael Dunn. By defeating Parmen with his own weapon, Kirk has gained a measure of ironic retribution for the humiliation that he and his crewmates had to endure. When I was a kid I especially enjoyed watching Kirk turn the tables on Parmen who I had come to despise by the end of the episode. As this was a Season 3 episode, no further mention of the Platonians or the Kiranide power is ever made or what became of Alexander after he departed with the Enterprise.
Plato's Stepchildren isn't among my favorite Star Trek TOS episodes but it did feature some very interesting ideas and of course has been a subject of past discussion because of the kiss between Uhura and Kirk.
