Aired: 9/20/1968
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.
Aired: 9/27/1968
The crew of the Enterprise are on a secret mission to steal a Romulan cloaking device.
Aired: 10/4/1968
An alien device on a primitive planet erases Captain Kirk's memory, and he begins a new life with the planet's indigenous people.
Aired: 10/11/1968
On a distant planet, Kirk, Spock and McCoy find a scientific team dead, and their children who, unknown to the crew, have great powers at their disposal.
Aired: 10/18/1968
The Enterprise travels with an alien ambassador whose appearance induces madness.
Aired: 10/25/1968
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.
Aired: 11/1/1968
An alien force drives the crew of the Enterprise into brutal conflict with the Klingons.
Aired: 11/8/1968
The crew of the Enterprise rush to stop an asteroid from colliding with a Federation world, but discover the asteroid is actually an inhabited generation ship.
Aired: 11/15/1968
Captain Kirk is caught between dimensions while the crew of the Enterprise works to retrieve him. All the while, the Tholians demand that the Enterprise leave their space.
Aired: 11/22/1968
The crew of the Enterprise encounters an ageless and sadistic race of humanoids with the power of telekinesis and who claim to have organized their society around Ancient Greek ideals.
Aired: 11/29/1968
Invisible "time-accelerated" aliens take over the Enterprise and attempt to abduct the crew for use as "genetic stock".
Aired: 12/6/1968
While visiting a doomed planet, the landing party is subject to torturous experiments by powerful aliens.
Aired: 12/20/1968
The USS Enterprise ferries a spoiled princess whose betrothal to a royal Troyian is hoped will bring peace to a star system at war.
Aired: 1/3/1969
Captain Kirk faces off with a demented shape-shifting starship captain determined to control the universe.
Aired: 1/10/1969
The Enterprise encounters two duo-chromatic and mutually belligerent aliens who put the ship in the middle of their old conflict.
Aired: 1/17/1969
A race of overpopulated aliens abduct Captain Kirk to solve their problem.
Aired: 1/24/1969
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.
Aired: 1/31/1969
Strange incorporeal aliens threaten the Memory Alpha station and the Enterprise.
Aired: 2/14/1969
The crew of the Enterprise encounter an immortal human in this science fiction variation on Shakespeare's The Tempest.
Aired: 2/21/1969
The Enterprise picks up a group of space "hippies" looking for Eden.
Aired: 2/28/1969
Captain Kirk races against time to acquire plague-fighting minerals from a world in the midst of a civil uprising against a grievous social class disparity.
Aired: 3/7/1969
Aliens force Captain Kirk and First Officer Spock to join forces with "Abraham Lincoln" and "Surak" to battle villains in a contest of good vs. evil.
Aired: 3/14/1969
Kirk, Spock and McCoy are trapped in two parts of another planet's past - a world threatened with destruction when its sun goes supernova.
Aired: 6/3/1969
The Enterprise is in danger when Janice Lester, one of Kirk's former lovers, steals his body.
