Telepathic aliens take control of Kirk and Spock‘s bodies with the intention to build new, mechanized bodies for themselves.

Captain Kirk must decide how to save a primitive people from the technological interference of the Klingons.

The crew of the Enterprise encounters an energy-draining space creature.

The Enterprise visits a planet with a violent culture based on Americas 1920s prohibition era.

Mr. Scott is implicated in a series of bizarre murders.

Tribbles – purring, fluffy, and fertile creatures – disrupt the exploitation of a disputed planet between the Klingons and Federation

The crew of the Enterprise become entangled in a planet’s tribal power struggle.

Captain Kirk becomes obsessed with destroying a murderous entity that killed many of the crew of his old ship.

Strange radiation exposes the command crew of the Enterprise to the effects of rapid aging

A shuttle crew from the Enterprise encounters a castaway (who appears to be Zefram Cochran, the inventor of Warp Drive) and his mysterious alien companion.

While transporting dignitaries to an important peace conference the Enterprise is pursued by a mysterious vessel and an assassin is discovered among the passengers

Two powerful aliens threaten the well-being of the Enterprise and her crew with their magical powers.