Air date: 1973-09-08

Runtime: 24 min

Stardate: 5521.3 In orbit around a dead star, the Enterprise comes across a huge starship inhabited by a parasitic life form that threatens the entire ship.

Air date: 1973-09-15

Runtime: 24 min

Stardate: 5373.4 Spock travels back in time to prevent his death as a young Vulcan.

Air date: 1973-09-22

Runtime: 24 min

Stardate: 5371.3 The crew of the Enterprise races to find a way to stop a cloud from destroying inhabited planets.

Air date: 1973-09-29

Runtime: 24 min

Stardate: 5483.7 Female crew members must take over the Enterprise when the men are incapacitated by a race of sirens.

Air date: 1973-10-06

Runtime: 24 min

Stardate: 5392.4 Cyrano Jones introduces tribbles that cannot reproduce.

Air date: 1973-10-13

Runtime: 24 min

Stardate: 5143.3 The Enterprise finds a long-lost explorer.

Air date: 1973-10-20

Runtime: 24 min

Stardate: 5554.4 A race of plant people, and their master, have a plan to force peace onto the galaxy.

Air date: 1973-10-27

Runtime: 24 min

Stardate: 1254.4 At the center of the galaxy, the Enterprise discovers a race of powerful aliens.

Air date: 1973-11-03

Runtime: 24 min

Stardate: 5591.2 Kirk returns to the "shore leave" planet, but it's not as peaceful as it was when they last saw it.

Air date: 1973-11-10

Runtime: 24 min

Stardate: 4978.5 Space con artist Harry Mudd returns, selling a fake love potion.

Air date: 1973-11-17

Runtime: 24 min

Stardate: 5577.3 The Enterprise crew begins to shrink after radiation exposure.

Air date: 1973-11-24

Runtime: 24 min

Stardate: 5267.6 The Enterprise crew must work with Klingons to escape from a pocket universe.

Air date: 1973-12-01

Runtime: 24 min

Stardate: 5499.9 While exploring the planet Argo, Kirk and Spock are turned into water breathers.

Air date: 1973-12-15

Runtime: 24 min

Stardate: 4187.3 Spock, Sulu, and Uhura discover a time capsule from an ancient and technologically advanced race. However, it draws some unwanted attention.

Air date: 1974-01-05

Runtime: 24 min

Stardate: 5501.2 Telepathic aliens put Kirk, Spock and McCoy in a zoo.

Air date: 1974-01-12

Runtime: 24 min

Stardate: 5683.1 Kirk and Spock are recruited for a heist to recover a stolen relic, which if not recovered could spark an galactic jihad.