When a mysterious alien race destroy an Earth colony, the Enterprise pursues, but Kirk and the alien captain are forced to fight each other by powerful aliens.

The Enterprise picks up a crew of genetic supermen from the 20th century... and their leader, Khan, plans to create a new empire.

The Enterprise arrives at a planet to establish diplomatic relations and finds itself in the middle of a "peaceful" war that threatens to destroy the ship.

Kirk investigates a series of grisly murders on a mining planet that are the work of a seemingly hostile alien creature.

The Federation and the Klingon Empire teeter on the brink of war as Kirk investigates Organia, a humble planet, inhabited by pacifists, that is unwittingly caught in the middle.

The crew of the Enterprise are held captive by an alien who turns out to be the Greek god Apollo.

The crew of the Enterprise visits a mysterious paradisical planet controlled by a computer that is served by the local inhabitants.

A shuttle crew from the USS Enterprise encounters a man out of history and his mysterious alien companion.

The Enterprise visits a planet with an Earth-like 1920s gangster culture.

The Enterprise crew investigates the disappearance of a ship's crew on a planet that is a modern version of the Roman Empire.

An alien female beams aboard the ship and, after incapacitating the rest of the crew, surgically removes Spock's brain. Kirk and the crew have just hours to locate and replace it before Spock's body dies.

Having been found trespassers into Melkotian space, Captain Kirk and his companions are sent to die in a re-enactment of the gunfight at the O.K. Corral.

Invisible "time-accelerated" aliens take over the Enterprise and attempt to abduct the crew for use as "genetic stock".

The Enterprise encounters two duo-chromatic and mutually belligerent aliens who put the ship in the middle of their old conflict.