With both their ships held captive by powerful beings, Kirk and the captain of the alien vessel are placed on an asteroid to fight for their lives and the lives of their crews.

The Enterprise encounters a seemingly peaceful civilization run by a "benevolent" being named Landru... who intends for them to join his people.

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.

Kirk and Spock must travel into the past in order to correct a change that will alter history.

First Officer Spock returns to his home world for a brutal Vulcan mating ritual.

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

Two powerful aliens threaten the well-being of the Enterprise and her crew.

The Enterprise must transport dignitaries to a peace conference, with an assassin on the loose.

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

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

A series of bizarre murders points to Mr. Scott as the prime suspect.

The Enterprise must protect a very important shipment of grain from both Klingons and some adorable creatures called tribbles.

The crew of the Enterprise encounters an energy-draining field which may be able to destroy the galaxy.