1-03: Where No Man Has Gone Before
An incident on the edge of the galaxy transforms two crew members, one of whom is a long-time friend of Captain Kirk.
1-07: What Are Little Girls Made Of?
The Enterprise finds Nurse Chapel's long-lost fiance, Dr. Roger Korby, living isolated with advanced androids.
1-25: The Devil in the Dark
The Enterprise encounters a silicone-based life-form who is attacking pergium miners.