1967: The first season ended with S01E29 “Operation: Annihilate!” [http://memory-alpha.wikia.com/wiki/Operation_–_Annihilate!_(episode)] Stardate 3287.2: The Deneva colony is attacked by neural parasites that cause mass insanity while the crew of Enterprise search for a way to stop them.
The episode featured Kirk’s nephew, Peter. However, a scene featuring dialogue between Kirk and his nephew that concerned Peter’s returning to Deneva to live with Sam Kirk’s partner was cut. Peter was played by Craig Hundley, who also played Tommy Stames in “And the Children Shall Lead“. Now a musician and going under the name Craig Huxley, he produced the music for the Genesis Project simulation that appeared in Star Treks II & III.