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

The crew of the USS Enterprise deals with an indestructible planet-destroying space probe.

A transporter mishap swaps Captain Kirk and his companions with their evil counterparts in a parallel universe. In the so-called Mirror Universe, the Enterprise is a ship of the Terran Empire, an organization as evil as the United Federation of Planets is benevolent.

Captain Kirk has a second run-in with the conman, Harry Mudd. Mudd is now the supreme ruler of a planet of androids who cater to his every whim.

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

Captain Kirk and his companions are abducted into slavery and trained to fight as gladiators for the gambling entertainment of three disembodied beings.

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

The crew of the Enterprise discovers Klingon interference in the development of a formerly peaceful planet and is forced to help maintain a balance of power.

Ancient alien minds are given control of Captain Kirk's and First Officer Spock's bodies.

The crew of the Enterprise tracks down a Federation observer on a planet dominated by a "Naziesque" regime.

Beings from another galaxy commandeer the Enterprise in an attempt to return home.

A skeleton Enterprise crew are assigned to test a revolutionary computer system that is given total control of the ship.

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

Kirk, McCoy, and Sulu are stranded on a barren planet where a mysterious woman attempts to kill them one at a time, while the Enterprise must travel halfway across the galaxy to rescue them.

Strange incorporeal aliens threaten the Memory Alpha station and the Enterprise.

The crew of the Enterprise encounter an immortal human in this science fiction variation on Shakespeare's The Tempest.

The Enterprise picks up a group of space "hippies" looking for Eden.

The Enterprise is in danger when Janice Lester, one of Kirk's former lovers, steals his body.