Telekinetic humanoids on Platonius torment the crew for sport.
The Enterprise answers a distress call from Platonius, home to a small group of humanoids who once lived on Earth in the age of ancient Greece and have since gained telekinetic powers. Their leader, Parmen, is seriously ill, and after McCoy treats him the Platonians demand that the doctor stay for good.
When Kirk refuses, they use their powers to humiliate Kirk, Spock, Uhura and Nurse Chapel, forcing Kirk and Uhura to kiss. Their dwarf servant Alexander, the only one without powers, helps the crew learn that the ability comes from kironide in the local food. The kiss is often cited as one of the earliest interracial kisses on American television.