Season 2 (1974)
- 9/7/1974. The Pirates of Orion — When Spock is afflicted with a life-threatening illness, the Enterprise must engage Orion pirates who have stolen a shipment containing the rare drug needed to save Spock's life.
- 9/14/1974. Bem — The Enterprise takes on an independent observer from an alien world, who insists on accompanying the landing party on a research mission of a primitive alien civilization.
- 9/21/1974. The Practical Joker — When the Enterprise passes through an energy cloud, the computer begins malfunctioning and pulling practical jokes upon the crew.
- 9/28/1974. Albatross — McCoy is arrested by an alien government and accused of causing a deadly plague during a visit nearly two decades earlier.
- 10/5/1974. How Sharper Than a Serpent's Tooth — The Enterprise follows a probe of unknown origin into deep space, where they find an alien entity with mysterious ties to ancient Earth civilization.
- 10/12/1974. The Counter-Clock Incident — An alien ship pulls the Enterprise into a supernova, transporting the ship to an alternate universe where time runs backward.