Star Trek S1:E12

Beyond the Farthest Star

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.

Yesteryear

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

One of Our Planets Is Missing

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

The Lorelei Signal

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

More Tribbles, More Troubles

Stardate: 5392.4 Cyrano Jones introduces tribbles that cannot reproduce.

The Survivor

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

The Infinite Vulcan

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

The Magicks of Megas-tu

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

Once Upon a Planet

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

Mudd's Passion

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

The Terratin Incident

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

The Ambergris Element

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

The Slaver Weapon

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

The Eye of the Beholder

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

The Jihad

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.