Aired: 9/15/1967
First Officer Spock returns to his home world for a brutal Vulcan mating ritual.
Aired: 9/22/1967
The crew of the Enterprise are held captive by an alien who turns out to be the Greek god Apollo.
Aired: 9/29/1967
The crew of the USS Enterprise deals with an indestructible planet-destroying space probe.
Aired: 10/6/1967
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.
Aired: 10/13/1967
The crew of the Enterprise visits a mysterious paradisical planet controlled by a computer that is served by the local inhabitants.
Aired: 10/20/1967
The starship Enterprise and its heavily-damaged sister ship, the USS Constellation, must work together to stop an alien planet-killing machine headed for the heart of Federation territory.
Aired: 10/27/1967
Two powerful aliens threaten the well-being of the Enterprise and her crew.
Aired: 11/3/1967
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.
Aired: 11/10/1967
A shuttle crew from the USS Enterprise encounters a man out of history and his mysterious alien companion.
Aired: 11/17/1967
The Enterprise must transport dignitaries to a peace conference, with an assassin on the loose.
Aired: 12/1/1967
The crew of the Enterprise become entangled in a planet's tribal power struggle.
Aired: 12/8/1967
Strange radiation exposes the command crew of the Enterprise to the effects of rapid aging.
Aired: 12/15/1967
Captain James T. Kirk becomes obsessed with destroying a deadly entity he once encountered in his youth.
Aired: 12/22/1967
A series of bizarre murders points to Mr. Scott as the prime suspect.
Aired: 12/29/1967
The Enterprise must protect a very important shipment of grain from both Klingons and some adorable creatures called tribbles.
Aired: 1/5/1968
Captain Kirk and his companions are abducted into slavery and trained to fight as gladiators for the gambling entertainment of three disembodied beings.
Aired: 1/12/1968
The Enterprise visits a planet with an Earth-like 1920s gangster culture.
Aired: 1/19/1968
The crew of the Enterprise encounters an energy-draining field which may be able to destroy the galaxy.
Aired: 2/2/1968
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.
Aired: 2/9/1968
Ancient alien minds are given control of Captain Kirk's and First Officer Spock's bodies.
Aired: 2/16/1968
The crew of the Enterprise tracks down a Federation observer on a planet dominated by a "Naziesque" regime.
Aired: 2/23/1968
Beings from another galaxy commandeer the Enterprise in an attempt to return home.
Aired: 3/1/1968
Captain Kirk must find the cure to a deadly disease and put an end to another Starfleet captain's cultural interference.
Aired: 3/8/1968
A skeleton Enterprise crew are assigned to test a revolutionary computer system that is given total control of the ship.
Aired: 3/15/1968
The Enterprise crew investigates the disappearance of a ship's crew on a planet that is a modern version of the Roman Empire.
Aired: 3/29/1968
While back in time observing Earth in 1968, the Enterprise crew encounters the mysterious Gary Seven who has his own agenda on the planet.
